# My GIK Pillar Trap Review



## thewire

I had pretty much dismised the idea that I could sit anywhere near the front of my room. My room is under a garage and has concrete on every side with some added reinforcement of 2" thick steel on the ceiling. I had installed Helmholtz Resonators in the back of my room, some GIK 244's centered on the back wall, a drop ceiling by Ceilume with a direct mount system using back panels filled with insulation, then Quiet Batt or insulation above that. I also had each tri-corner stacked with 12" Roxul 60, a stage filled with tons of insulation, riser with lots of insulation, and four 2" panels at each of my first reflection points, with another 2X2 2" panel under my center channel. I used my equalizer to cut the peaks in my room.

I won a GIK Pillar Trap in the Shack giveaway and gave that a try in my front right corner, where I had found needed the most improvement. The bass would all the sudden get real loud from the corner and overpower the rest of the sound without the trap there. When I first placed it there I noticed that there was more life to sounds from that direction. I would measure that it was eliminating all kinds of peaks in the corner when I used REW.

I tried the trap in my left corner where I less problems feeling bass from, but instead where I heard more midbass punchiness. I decided I wanted another one there also. I won yet again another Shack giveaway and used the money to get a second GIK Pillar Trap and another pair of GIK 244's. I also received another pair of GIK 244's as a gift from my family. I used one pair of my new GIK 244's spaced away from the walls at my first reflection points, and placed the new trap in the left corner. I decided to raise it up some using some methods and am in the proccess of treating some more area under my screen. I placed my four subwoofers at each walls (pretty close to being :innocent midpoints per Bryan's recommendations and adjusted my seating, and the ringing is gone from when I had tried this before. :yay2: REW will now recommend a filter at 25Hz but I am not hearing this problem yet and I am currently watching movies without the use of equalization. I am still trying things with the second pair of GIK 244's which I have placed over the large openings in the back of my room that are some openings into the Helmholtz Resonators in the middle of the room bellow my other GIK 244's. I have tried many things with the Helmholtz Resonators and may try filling those with insulation again.
I am still in the experemental stage, treatment stage, but the room sounds fabulous right now. :T

Edit: I will post some photos of the rooms progress and a couple measurements later this AM.


----------



## thewire

Here are photos of the rooms progress and a measurement of the front rows center seat with the left channel with subs, and right channel with subs. The measurement is taken as is.. I think I will trying some more concrete tiles under the sub on the stage. As it is one layer is helping for the back row, but I have some others not in use I may as well try placing under there as well. I have the needed materials to finish making the frame for the stage traps and the fabric has been ordered.

There are small holes in the corners of the room behind the carpet with the Helmholtz Resonators, and there are holes in the stage behind that opening in the center that were big enough to place my hand inside, then stuff more insulation. I can't fit anymore insulation in that stage.
































































Spectral decay of the left and right channel. Notice in the frequency response how close left and right match. That was my primary objective so to speak as I always had problems with this in my last HT. My other goal was tight bass to at least 25Hz and no audible distortion. My other goals are surround sound music, and video games. I have not yet gotten to the games, but the surround sound music was accomplished awhile back, and will need to check on that again.


----------



## bpape

Looking good. Glad things are working for you. 

Getting the subs right makes a ton of difference. 

Bryan


----------



## thewire

Yes it does, and I now have more room to bring other seats in when we need to do so. I think I knocked loose one of the bi-wiring in my right surround inside the ceiling when I was moving materials up there. I'm having to connect that right surround to the rear right surround. The subs wiring I can run to the older wiring between the Helmholtz Resonators and move the wire from the left surround I'm using for that currently. You can see some of it there in the photo hanging out of the wall. I'm not sure it will be worth to fix the surrounds wiring since I will be moving that later anyway. I may just run one of my black wires until then, but if I am in the ceiling already, I may as well.

The 12' fabric 56" wide will be enough to cover the front area, then using some left cover the stands for the Pillar Traps that I used to elevate them. Then if I can clean things up some it will be in good shape I beleave. Firing the two subs at the left and right walls midpoints resulted in a 5dB dip at 70Hz hence they are about half a foot apart. I will let you know how it turns out, and be sure to get some better photos.


----------



## thewire

I am think that cutting out the front of the stage and the platforms, then placing some fabric over those as well might be benificial to the 30Hz - 40Hz, and 70Hz area. I don't see how it would hurt anything, and if the dip from 30Hz and 40Hz decay (which is a smooth dip in the response) is improved by doing so, as was adding more insulation inside the stage, I could move my front back 1', and my back row forward 1'. When I had all the subs at the walls midpoints, the ringing at 25Hz was substantially lower in my measurements, so if getting rid of some resonances means being able to do, I think it may help. I did not notice any changes when placing the GIK 244's across my front stage, which makes me curious whether the zero point energy is being directly reflected off the front of the stage in these frequencies, or it is a resonance. My modes are spaced fairly far appart there.

Here is a mode calculator example of what I am thinking may help at the front wall/floor.


----------



## thewire

I'm now in the testing phase with framing the front stage bass traps. I decided to remove the upper portion of the stage, and took a couple 2X4's flanking out the front of my wall with it. I'm will be testing with the entire thing of R19 there this time. That's cardboard at the top there that is stapled to the framing in the front.


----------



## thewire

Sorry I had to do these with my hush box fan running. I was able to reduce the ringing down low as I was hoping. The ringing low was removed prior to moving the subwoofer so they were firing at the same points along the walls. The mains are not calibrated as of yet, and it seems they went down in level. It might have been the small amount of insulation I removed from the corners, or I need to adjust the traps again. I doubt it was anything to do with the cable management I have been working on. I adjusted the gain a couple decibals higher. Here is a comparrison of before and after what I just did looking at the lower range. I almost gained 1Hz lower extention, and the 30Hz - 40Hz area is improved. I noticed that the other gain went up overall after moving the subwoofer, and positioning the seating effects the 50Hz - 200 Hz area gain. I saw very little change to 30Hz - 40Hz this time, but moving the seating was effecting my left right speakers response more, which I did not move. 

Before










After


----------



## bpape

Nicely done. This is a perfect example of a very methodical exploration of, and finding solutions to low end issues.

Bryan


----------



## fredk

And a fine example of exaclty how much bass trapping is required to tame a nasty room. Sigh... That doesn't bode well for me as I do not have the kind of room thewire does.

Nice job on the HT my friend. It has been an interesting read.


----------



## thewire

fredk said:


> And a fine example of exaclty how much bass trapping is required to tame a nasty room. Sigh... That doesn't bode well for me as I do not have the kind of room thewire does.
> 
> Nice job on the HT my friend. It has been an interesting read.


Thank you. I have also measured results using one subwoofer in a much larger space in my living room. I placed a sub in at the right wall and the GIK Pillar Trap in my kitchen, and observed the best improved decay with it there having the mic near the dinning table. I concluded that would be a difficult area for me treat then. This area is meant to be a game room in the future and the kitchen is suppossed to become the snack area. I am still trying to learn in preperation for the media room project which is in the planning stages. I also hope that my room treatments will give me as good as results should I take them to another room in the future. 

The 50Hz and 80Hz area is espicially difficult to treat as that would require lots of absorption on my back wall.

The only changes I have made since to the room was placing the sub under the new bass trap at the front of the room with the 2" panel behind it, and removing the stack of concrete behind it to see what difference this makes. I also removed some insulation above my projector since the tubes have been shutting on/off, and I thought it might be something to do with heat, regardless that my hush box fan is attempting to remove the hot air inside.


----------



## thewire

To be fair to others, and since I have been contimplating the idea to move my seats back a foot, here is with the GIK Pillars now stacked on the back center wall onto the 4 other GIK 244's. I moved the left and right speakers away from the walls as well, and moved my surrounds behind the back row.

You can see how the 250Hz area in the decay now results in a better match, and the lower ringing has changed. The ringing is so low that I must zoom into 200ms with the waterfall to observe the decay more closely. This is again with the hush box fan running. The lower ringing now moves to the 20Hz area, bellow my first room mode.


----------



## thewire

Some photos also for better understanding of the layout measured. :whistling:


----------



## thewire

This sounds very good also, espicially in the LFE. Simply moving my speakers out however does not seem to be addressing the issues I heard in the front corners in my first post. I'm thinking then it must be related to the subwoofers output, somewhere in the range of 90Hz, - 120Hz, but it also treated much higher for the mains response, and much lower for the subwoofers response. If the problem in the right corner that I am feeling can't be heard, then these traps must be treating very low.


----------



## thewire

I isolated my subwoofers on the platforms and the stage using my subdude and put holes in the stage. It seems I now have no need to adjust the trim for the left or right speakers to match. Drilling all these holes without moving the speakers was difficult.

I had to arrange the panels so that reflections from the ports at the bottom of the speakers would be absorbed, and I moved the subwoofers slightly. These measurements were after equalizing the subs.


----------



## thewire

Next I might like doing something like this with more trapping. The rear traps I could optionaly place insulation behind. A false wall was out of the question back there because of the sconces. There seems to be a slight bit more bass from the sub on the right wall when in the right seat, and sitting in eather the left or right seat up front which are closer to the walls, the spaciousness seems about lost as more bass seems to come from the speakers closest. Having traps above the subwoofers at the walls midpoints seems to help that but not 100% sure. It just seems to make the balance from the mains to the subs more smoothed out for those seats. That seems to happen at around 92dB or more. It could be something to do with second reflection points but I suspect it's just some sound off the walls moving. More traps would deffinitly help the back wall.


----------



## thewire

I'm ordering some Roxul and then I will be adjusting the other room treatments to see what results I can get.

Anyone know where I can get 6 Roxul Rockboard 60 2 inch, Case of 6 for less than $461.44 shipped to area code 65072?


----------



## bpape

Roxul - probably not. If you can use IIG, I know I can get some for you for better than that. 

I have a commercial FedEx account for my business. I'm getting about $19.50 per box for shipping so that'd be about $117 for the 6 boxes. I'm guessing I could get you the mineral wool for around $300

I used to carry it but have been having QC issues and problems with the warehouse so I discontinued it. I'd be willing to grab you some though and ship to you. We're not that far away - It would be just as easy to meet somewhere in the middle if you have a truck and we can figure out a time.

Bryan


----------



## thewire

bpape said:


> Roxul - probably not. If you can use IIG, I know I can get some for you for better than that.
> 
> I have a commercial FedEx account for my business. I'm getting about $19.50 per box for shipping so that'd be about $117 for the 6 boxes. I'm guessing I could get you the mineral wool for around $300
> 
> I used to carry it but have been having QC issues and problems with the warehouse so I discontinued it. I'd be willing to grab you some though and ship to you. We're not that far away - It would be just as easy to meet somewhere in the middle if you have a truck and we can figure out a time.
> 
> Bryan


I'm without any kind of transportation for awhile until we replace my van that just went into retirement. I'm not familiar with IIG. Is that acoustical cotton? For some reason the more coverage I get in the back of the room the better results I measure. It needs to be very thick according to measurements. My projector also just went into retirement and until we can get a 1080P DLP after the tax season and paying off some dentist bills for our family I will be using my 32" flat screen with progressive input and anamorphic sqeeze for the HT. The good news is that I can treat the front wall or the back wall, and move my speakers away from the walls. As they had to be they were 20" from my side walls for the best response, but it landed them right into a null from my axial width modes.

I really need as much as I could get my hands on. Having this room size is espicially challenging and I need to have a live-end dead-end approach to get it sounding anywhere good for movies I think. My front wall and back walls modes are so bad that I have them all the way up into the 120Hz area. 

You can see the modes that I am currently after in this image. If I have any left-over but which I doubt I would have there is plenty of room in the ceiling to deal with the third order and first order modes.










When I tried 4' thick pink R19 in the rear of the room I had very impressive results but not down to 57Hz as much as I would have liked. It did very well for the 80Hz area in my mesurements. I tried some Quiet Batt back there also but it didn't sound right for some reason. I tried filling those Helmholtz Resonators with pink also but it did not improve the decay much and it somehow seemed to do more harm than good as they seem to effect the 67Hz first order ceiling mode in a negative way, espicially if I change the volume inside. I had not tried any Roxul in that before, but I see the treatments helping over a more larger area, espicially on the sides of where the GIK 244's are currently back there. The biggest problem I have with those is that they are flanking the back wall some. It actually travels right up the wall through the garage and into my room in the back right corner away from the door. My projector hush-box also has some issues with flanking but that's not as difficult to deal with. 

I thought Roxul 60 might work well for a cost effective approach in covering such a large area. If your willing to pick some up for me and ship it also that would be great. I'm still open to other ideas however. I will probobly need to wait until monday before I could order anything over $400, and I need to check what I have in there after some recent expenses.


----------



## bpape

IIG is just a different brand of mineral wool instead of Roxul brand.

Rear wall is fine for thicker. Doing too much on the front will skew too much of the boundary effects IMO. Usually we just do 2" on the front in most rooms.

Bryan


----------



## thewire

bpape said:


> IIG is just a different brand of mineral wool instead of Roxul brand.
> 
> Rear wall is fine for thicker. Doing too much on the front will skew too much of the boundary effects IMO. Usually we just do 2" on the front in most rooms.
> 
> Bryan


I see. The MinWool-1200® Industrial Board looks like I would need then. If that is easiest for you to get I will go with that then. I don't really have a preferance for which brand.


----------



## bpape

Lemme check with my supplier and see what they have in stock

Bryan


----------



## thewire

Checked my account this AM. Are you able to get the $300.00 of the mineral wool? I wanted to set some aside in case I needed an extra pair of 244's.


----------



## bpape

Check your PM


----------



## thewire

If shipping is more that is alright by me. The Pink insulation in the back didn't seem to help more than 2' thick but I'm not sure the difference with mineral wool. If it is enough to go 2' thick, 4' high, and however wide stacking them would be so that I cover the back wall around 10' wide I would be happy. That would be plenty to try out in other areas also. If shipping is more that is alright, or if I don't have enough I could wait until next week or later if that will help. I will have the other pair of 244's on the back wall to see if adding more may help, but it will take longer for me to determine if more will help or not. I will first try without covering the center area where the 244's are currently which I did last time. I thought it might be better to think ahead just in case, but the back wall is the main agenda.


----------



## thewire

I could also instead make it look nicer and place a second pair of 244's spaced on the back wall, then fill in the area behind them with as much Mineral wool as I could get, disregarding the side walls for now. I'm sure that would look nicer and I don't think I have the needed materials for the another frame, and I certainly don't have enough fabric although I have some black curtains that may work.

This is the left and right speakers with some 244's moving absorption to left or right side walls as shown in the previous image. The mains have a X-over of 80Hz.










These RT60 measurements never seem to change much, or if they do, I can't remeasure the same thing twice. They look similar having my my subs on also. The panels depending on where they are placed on the side walls makes the area around 250Hz go lower.










This is how the subwoofer measured with absorption on both side walls and with them also spaced more than 1' off the back wall on each side of the other 244's. The x-over on the sub is 80Hz but 120Hz is also sent tracking a 120Hz X-over.

green is with them on the back wall
blue is with them on the side walls


----------



## thewire

Placing the 244's over my stage now gives me reults I like. I moved out the subwoofer out from between the stage, placed insulation in there instead, and placed the other couch back in since I had a complaint about that. Checking the ceiling above the back row there is zero abrorption back there. I found some blankets that I stuffed up in the corners.

This is with four 244's across the front stage with some pink behind them in the center, a small amount of pink laying on the back center wall above the sub there, and the seats, and subs moved again. The stage has a 1 3/4" thick peice of plywood added to the top. The roll-off of the subwoofers in the front of the room looks really good. There are a few tiles missing in the back of the room.

Front row with a quick setup. No eq was done, and it doesn't look equalizable.










The back row looks scarry now. I have never seen such a lack of extention back there. This was without the small absorption on the back wall.


----------



## bpape

Sorry - been buried. I'll do some checking today.

Bryan


----------



## thewire

The highs didn't sound right. The best I could get it to sound was when I placed two 244's at the first reflection points with and additonal one stacked on each pair horizontal, then placed the 2" around my surrounds.


----------



## thewire

bpape said:


> Sorry - been buried. I'll do some checking today.
> 
> Bryan


That's alright. I appreciate it.


----------



## thewire

Here is my 2" on the front wall give or take some adjustments. I had to roll the High Power Screen against the wall while feeding the foam into it and then placing it back into my original box with a foam tube I wrapped in paper towls. The screws holding the frame in place are stripped and my drill will not open to put in a new bit. I have a second frame which was originally designed for it becuase this was a replacement screen from when I had help painting the room and they had painted the previous one on accident.


----------



## thewire

Did you check on mineral wool today? I tried calling IIG but the message said they were not in the office.


----------



## bpape

Actually, I went to call and realized I don't have the contact info in my new phone. Going back through my files from last year to get the info.

Bryan


----------



## thewire

I burned some custom ticks and beats to CD and I notice that placing absorption at the side walls in the middle corrects some coloration in the 80Hz area where it instead of sounding localizable from the front to the back of the room it sounds like it is more in phase. I notice that the 250Hz seems to reflect of my ceiling and bounce to the floors corners with some build up there. There is some higher pitched reverberation that seems to dominate on the right side of the room in the front, and the left side of the room in the back. This seems related to the second reflection points. If I were to address these problems, I wonder if adding standard R19 insulation in the back of the room would sound alright and less punchy.


----------



## thewire

Very interesting. I checked the reference material for which I had the problem with and placing some the 244's at the side walls midpoints the bass sound very even thoughout the room now but there is some deep sounding bass? from the left or right channels. It does not feel distracting that way. That has to be something with the 244's on the front wall. I think I just need some more 244's and I have listened to alot of material with them at each location, so I will go ahead and order a couple more pair of those for now unless anyone would suggest otherwise.


----------



## hjones4841

I don't have any experience with the 244s, so I cannot offer suggestions. As posted elsewhere, all of mine are Monsters. It seems that we both have done our share recently to keep GIK in business:whew:

I notice that your avatar lists media reviewer. Is that your profession? Is your room used in your business? I am an electrical engineer in nuclear power generating plant design. I always envisioned a career in electronics, but when I graduated from college in 1971, the space program was almost over and few electronics firms in the Southeast were hiring. So, power engineering pays the bills for the electronics addiction:nerd:


----------



## thewire

hjones4841 said:


> I don't have any experience with the 244s, so I cannot offer suggestions. As posted elsewhere, all of mine are Monsters. It seems that we both have done our share recently to keep GIK in business:whew:
> 
> I notice that your avatar lists media reviewer. Is that your profession? Is your room used in your business? I am an electrical engineer in nuclear power generating plant design. I always envisioned a career in electronics, but when I graduated from college in 1971, the space program was almost over and few electronics firms in the Southeast were hiring. So, power engineering pays the bills for the electronics addiction:nerd:


Yes I review movies here over in the Media Review forum. If not I would be unemployed like the other 85% in my area during the winter months. Hopefully it will be a better season here at the lake than last summer when it had seemed to rain or storm just about every day. My grandfather always tinkered with electronics and gadgets and my great great grandfather had contributed to MGM for them to get started so it has always been a hobby of mine. It makes my other family members are very jealous when they come over. :bigsmile: I recently took a trip up midwest and got THX certified. A couple summers ago I had inventation from the academy awards to review movies which I would have taken but my family wanted me to have a "normal" job. I might have to write them back to see if they are still interested or not some time.


----------



## thewire

I Ordered two Monster traps, but I will get some more 244's later this week. I could probobly get the insulation free.


----------



## hjones4841

I think you will be pleased with the performance. At least on paper, they are quite a bit more effective in the lower octaves than the 244s. Bryan indicated that stuffing some pink insulation behind them may improve absorption performance in the lowest bass. I haven't tried that yet.

There is about an inch or so gap at the back of the trap between the back of the material and the back edge of the frame. I suppose the intent is to provide that as an air space even if the trap is pushed against the wall. That may even be there on the 244s.

Something to remember is that GIK will make a custom size of any of their traps for a very nominal fee (I suppose as long as it is within the 24x48 standard). And if you buy more than one, the surcharge for the other custom ones of the same size is even less.


----------



## thewire

hjones4841 said:


> I think you will be pleased with the performance. At least on paper, they are quite a bit more effective in the lower octaves than the 244s. Bryan indicated that stuffing some pink insulation behind them may improve absorption performance in the lowest bass. I haven't tried that yet.
> 
> There is about an inch or so gap at the back of the trap between the back of the material and the back edge of the frame. I suppose the intent is to provide that as an air space even if the trap is pushed against the wall. That may even be there on the 244s.
> 
> Something to remember is that GIK will make a custom size of any of their traps for a very nominal fee (I suppose as long as it is within the 24x48 standard). And if you buy more than one, the surcharge for the other custom ones of the same size is even less.


I thought about trying some insulation behind the 244's. It is also 1", 1" 1/4" I think actually. I could fit some pink behind it but I don't have much to spare at the moment. I was looking at the absorption coefficients yesterday of the 244 again and I saw the Monster and looking at them they seem to center right around the problem target frequency in my room. I kept putting them in the checkout, leaving awhile comming back, putting them back in. I'm glad those are ordered finally. I talked to Bryan before about custom sized traps for the small area on my stage, but the cost was out of my price range at the time. Those are still on file should I decide to do that, but with the new Pillar traps there they would be slightly smaller. I'm pretty sure the insulation on there does at least at decent enough amount of absorption.

I could see the Monsters helping above the 244's at the first reflection points or on the front wall. Since I can freely move the speakers I'm not sure I would benifit having them at the first reflection points. My speakers mostly are performers in the mid-bass area although they do go down to 28Hz. It's all these subwoofers in a concrete room that are so difficult. Having the subs at each walls midpoint is suppossed to loose around 12dB - 18dB that way, but I think that I did not loose near that much.


----------



## thewire

Replaced a tile on my ceiling with a panel, moved insulation from the front stage (except corners) to the rear of the room, placed left reflection point panels on the stage with the other 244's and took the other 2" panel at the top of the screen wall into the other room to at least maintain symmetry on the front wall. I lost a couple decibals of SPL and equalized to a lower target loosing some headroom but I'm not sure how much. I turned my subwoofer level up so that is nearly +4 higher than the mains. I probobly should just eq to 25Hz which I may do next time but I thought it might be interesting to equalize some around the first room mode. This one is +-9dB. What is more important is what this sounds like.


----------



## hjones4841

I had thought about putting a couple of Pillar or Table Top traps in the room to replace two tables that I removed. I would be interested in your take on the peformance of the Monster vs. the Pillar. From the website, it seems they are similar since there is absorption from all sides on the Pillar.

I am still simply amazed at the difference traps made in my room. Wife and I watched AI last night and I kept having to turn the sub down (and the volume down on some singers:bigsmile. The bass is so much more omnidirectional now, probably due to taming peaks in the mid bass more than anything else.


----------



## thewire

hjones4841 said:


> I had thought about putting a couple of Pillar or Table Top traps in the room to replace two tables that I removed. I would be interested in your take on the peformance of the Monster vs. the Pillar. From the website, it seems they are similar since there is absorption from all sides on the Pillar.
> 
> I am still simply amazed at the difference traps made in my room. Wife and I watched AI last night and I kept having to turn the sub down (and the volume down on some singers:bigsmile. The bass is so much more omnidirectional now, probably due to taming peaks in the mid bass more than anything else.


I will do a comparrison when they arrive. :T I think that I will have to measure/listen to the performance of each in a different room to base my opinion on the two, but I'm not entirely sure. With the Pillar Traps I just move them around the room and listen to the improvements, then measure. It was much easier than to measure, place them, then have to move them again to improve the results. It's not as quick a proccess to do that with the 244's, but if the Monsters are close to being like the Pillars, setup should be simple.


----------



## thewire

This is with 3 GIK 244's hung vertical at the first reflection points on each left or right wall, the 2" panels along the stage, Pillar Traps in the front corners with the insulation under them, added insulation inside the right ceilings corner, and insulation in the corners inside the Helmholtz Resonators in the back. I removed the reflective board in the ceiling above the left center and right speakers as well.

This gave me a large dip from the ports at the bottom of the speakers again.










I measured at 12" for the left speaker, then again at the floor.










I borrowed a 244 from the furthest first reflection point on the right wall and placed it on the floor horizontal next to the speaker, then remeasured. I then measured from the seat again. I looked at the the back row and the front row again. The Monster traps should be here tommorow. I still think I need another pair of 244's after seeing this problem come up again, and treating the back wall and front wall could wait. Suggestions are welcome, and I am undecided after several days of thinking about this which is more important. I tried with the insulation behind a couple of the 244's.


----------



## hjones4841

I am sure you thought of this already, but take some measurements of the 244 vs. Monster in the same location. It would be interesting to see how well the performance difference in your room correlates to the test reports. The test reports are what convinced me to go all Monster, since I was starting from scratch with traps and needed to maximize absorption per unit size. I suppose there is a tradeoff, tho. Absorption distributed thruout the room vs. more concentrated absorption at fewer places.


----------



## thewire

hjones4841 said:


> I am sure you thought of this already, but take some measurements of the 244 vs. Monster in the same location. It would be interesting to see how well the performance difference in your room correlates to the test reports. The test reports are what convinced me to go all Monster, since I was starting from scratch with traps and needed to maximize absorption per unit size. I suppose there is a tradeoff, tho. Absorption distributed thruout the room vs. more concentrated absorption at fewer places.


7" is as thick it goes for first reflection points I think. The Monsters control a more broad-range of frequencies, and are highly effective in those where music is critical. Right around the left and right speakers from where those sounds are coming from where I have boundary interferance could very well be a good place for them, and it could avoid exciting some slightly my room modes that are critical to left and right stereo imaging. As the pressure changes in the corners the percieved tonal balance from them changes, and this effects the important acoustic foci. I will give them a try there. :yes:

The back of my rooms corners effect the same frequencies, which is why I placed some insulation there.


----------



## thewire

This morning I have done my best to decouple the subwoofers from the side walls. The side walls are not attached to the ceiling except in small areas with caulk to prevent rattles, that are partially sealed off using fabric. The left wall is staggered, and the right, front, back walls are semi staggered with the framing attached to the concrete using liquid nails. Each board inside the HT is caulked or glued then nailed into place.

The subwoofer in the back I removed the stage, then sat the subwoofer on half dozen or so concrete tiles that I surrounded with insulation. The side ones I cut a hole under the Subdudes, added more insulation, then screwed them into the platforms using many nails so that I could space them from the wall, allowing the ports to breath. There is some area to absorb some energy from the ports on the side walls as well. The insulation will later be covered in fabric and I will refinish the subwoofers eventually with paint instead of the layer on them.



















This should help for the testing purposes, and I might gain back some acoustic energy from the subwoofers.


----------



## thewire

Here are the test results with the traps next to my main speakers ports at the floor on concrete. I placed a 244 or Monster in each corner in front of the corner trapping laying horizontal on the floor. They were beside the bottom of the 244's and spaced from the wall the distance of the 244's but the 244's are not perfectly flat against the wall. I measured each speaker with and without the subwoofers on, the subwoofers by themselves, and then repeated the test for each different trap. When a different trap was tested, it was removed from the area and brought into the house, not into the lobby next to the theater. The mic was not moved, and levels were not adjusted. You can click the thumbnails to see the larger images.

244 Traps

*right no subs 244* 1 sweep at 256K 1/24 smoothing


*right xo 244* 1 sweep at 256K 1/24 smoothing


*left no subs 244* 1 sweep at 256K 1/24 smoothing


*left xo 244* 1 sweep at 256K 1/24 smoothing


*before equalization subwoofers with 244 traps*5 sweeps at 256K


Monster Traps

*right monster no subs* 1 sweep at 256K 1/24 smoothing


*right monster xo* 1 sweep at 256K 1/24 smoothing


*left no subs monster* 1 sweep at 256K 1/24 smoothing


*left xo monster* 1 sweep at 256K 1/24 smoothing


*before equalization subwoofers with monster traps* 5 sweeps at 256K


*example subwoofer equalization with monster traps* 1 sweep at 256K


*example after subwoofer equalization with one main* 1 sweep at 256K


----------



## hjones4841

Interesting. Looks like narrower ringing frequency distribution in the 23-24 Hz range with the Monsters but with a higher amplitude. I think that happened in my room for the mods done last weekend. However, on mine the whole amplitude from 20-40 or so went up on the FR response plot. I am not seeing that on yours, unless you normalized the volume.

How many filters did it take to flatten the FR? Looks good.


----------



## thewire

hjones4841 said:


> Interesting. Looks like narrower ringing frequency distribution in the 23-24 Hz range with the Monsters but with a higher amplitude. I think that happened in my room for the mods done last weekend. However, on mine the whole amplitude from 20-40 or so went up on the FR response plot. I am not seeing that on yours, unless you normalized the volume.
> 
> How many filters did it take to flatten the FR? Looks good.


I'm not sure how accurate that is under 35Hz - 40Hz. Each time I measure the ringing changes from around at least 3 and up to 5 or 6 of the slices in the waterfalls. I did notice the response changing when I went from the 244's to the monsters quite easily, espicially in the room modes I was targeting for the test. I used 6 filters for my subwoofer. The target is a 120Hz crossover slope for LFE so I need to add some more filters than if I were to use a crossover from something such as a CD input. The desription of the optional settings on my Outlaw 950 are:



> 6-channel analog input
> bass management off: full-range speakers receive full-range signal, subwoofer receives LFE signal plus information below 80Hz from the other five full-range speakers ("double bass" condition); subwoofer also has a filter that discards material above 120Hz on the LFE input signal (material that subs typically can't reproduce well)
> bass management on: full-range speakers receive all information above 80Hz, subwoofer receives LFE signal plus information below 80Hz from other five full-range speakers; subwoofer also has a filter that discards material above 120Hz on the LFE input signal (material that subs typically can't reproduce well)


I have it set to the on position. The subwoofers themselves have no crossover, and are only powered by mono amps.

More on that here. To measure a more accurate reading I use a CD that I burned with REW of Pink PN in my CD player to check things when I am happy with results I get in the sweeps. 

I didn't touch any volume except that I calibrated levels of the mains to the target before I began measuring while I had the 244's in place. The settings were pre/pro master gain -10, subwoofer 0, mains +3 or +2. I have the gain turned up in REW so that it is a 75dB target instead of raising the gain on my pre/pro and lowering the volume in REW for the 85dB target.


----------



## thewire

I think that I see what you are saying about being effective down at 40Hz. In my measurements if I zoom in to 40Hz - 200Hz, and then lower the graph down I can see that there is a pretty effective amount of absorption around that range in the waterfall graphs.

yellow = Monster Traps
blue = 244 Traps


----------



## hjones4841

That is what I thought by just eyeballing the two waterfalls. Bet that is enough difference to be audible.


----------



## thewire

Yes they help quite alot. I was very impressed with listening to the entire Transformers movie while watching speakers move. :coocoo: I ordered a case of 6 2" OC 705 and am buying a Rane SSE-35 Home Theater Equalizer. I was not pleased with sound from the front wall with my compressed insulation, and the back of the rooms upper corners sounded like the bass was lacking somewhat, so I want to put the rest of my insulation back there again. I hope that my screen will act similar to having a layer of FSK. I may end up leaving the back of my room without absorption and get some dipole surrounds. The back row is not real concerned about having more treatments, and they are already happy with the improvements thus far and think it is fine how it is. I will listen carefully for slap echos off the back wall again, but I didn't hear it last I checked, and it may have had something to do with how I have changed the riser more recently.


----------



## hjones4841

My other two Monsters shipped today, so I should have them tomorrow afternoon (just one night to here from Atlanta). I will make a few measurements this weekend and post them. As stated earlier, I am limited as to where they will fit. Try putting a R30 batt behind the Monsters - Bryan said that might help in the lower freqs.

Not sure what you mean about the screen acting as FSK. Is it vinyl on a frame? If so, it should be reflective to mids/highs and not do much below that.


----------



## thewire

hjones4841 said:


> My other two Monsters shipped today, so I should have them tomorrow afternoon (just one night to here from Atlanta). I will make a few measurements this weekend and post them. As stated earlier, I am limited as to where they will fit. Try putting a R30 batt behind the Monsters - Bryan said that might help in the lower freqs.
> 
> Not sure what you mean about the screen acting as FSK. Is it vinyl on a frame? If so, it should be reflective to mids/highs and not do much below that.


Good idea. I have more than enough for that area on my stage, and I don't like it compressed, so I will put that behind the Monsters. I actually forgot to try that I was so busy.

The screen is a High Power Da-Lite screen that has a vinyl back on it. I think that I remember reading that FSK was not needed with a screen in front of it, but I don't recall the difference between a vinyl screen and FSK. I'm just hoping it reflects enough back above ear level. 

I have been busy today trying to get things setup. It seems easier to hear higher q resonances after adding the Monsters. I'm trying a couple layers of wood (over 3") added to the face of my Helmholtz Resonators and stacking the concrete tiles on the top of it. It sounds like it is helping in the back of the room at least. I'm also going to try various things above the first reflection points to see if I can improve anything with that, and make them more decorative. That's something I have not tried yet so I will give it a try. I hope to have things setup with what I have by the end of the night.

Do you have planned where you are putting the next Monster traps when those arrive?


----------



## hjones4841

I will probably start with them in the center rear wall, in front of a brick fireplace on the GIK stands. That is where Bryan initially recommended them for absorption from that wall to the center recliner. They worked well there, but are the ones I mounted horizontally in the rear corners. I can slide them around easily to find the 1/8th wavelength for the 27Hz peak that I have. Don't know what the point of diminishing returns is for my room; I will have 5 Monsters along that 12.5ft wall, counting the ceiling corners and the ceiling center, plus the two up front in the corners. 

(Hey, GIK, how's about a quantity discount for thewire and me:yes

I sent Glenn an e-mail about a simple mod to the GIK stands. Due to moving the first traps around, the wood blocks that fasten the stands to the traps were coming loose. They are held in place with two short nails. I drilled a small pilot hole between the brads and put in a 1" drywall screw. Sure tightened them up. I had thought about using wood glue, but was out of it. Glenn replied that they will look at using that mod.


----------



## hjones4841

thewire: I meant to ask you what brand/color of black paint worked best for you? Folks at AVSforums like Behr Mouse Ears, but say that it badly shows marks. I used a Glidden flat with a Behr color that Home Depot mixed for me. Color is fine, but has a slight sheen where light from the screen hits it.

Before I blacked out the whole ceiling, I covered two rows of tiles closest to the screen with Parts Express black grill cloth - looked great with no reflection or sheen, but too expensive to do the whole room.


----------



## thewire

hjones4841 said:


> I will probably start with them in the center rear wall, in front of a brick fireplace on the GIK stands. That is where Bryan initially recommended them for absorption from that wall to the center recliner. They worked well there, but are the ones I mounted horizontally in the rear corners. I can slide them around easily to find the 1/8th wavelength for the 27Hz peak that I have. Don't know what the point of diminishing returns is for my room; I will have 5 Monsters along that 12.5ft wall, counting the ceiling corners and the ceiling center, plus the two up front in the corners.
> 
> (Hey, GIK, how's about a quantity discount for thewire and me:yes
> 
> I sent Glenn an e-mail about a simple mod to the GIK stands. Due to moving the first traps around, the wood blocks that fasten the stands to the traps were coming loose. They are held in place with two short nails. I drilled a small pilot hole between the brads and put in a 1" drywall screw. Sure tightened them up. I had thought about using wood glue, but was out of it. Glenn replied that they will look at using that mod.


There is such thing as to much and there is also to little. The tonal balance and decay is important but there is a an amount that you will have to decide what sounds right. There are recommendations for how many sabins to absorb and also how it placed in the room. Many acousticians have a set of guidelines for how much to use and in what ways. You will want to find what works. It really takes more than one person to complete a room. It is a collabrative effort and I think that Bryan or others will tell you if you have overdone something and I read him telling someone when something is too much. 

Some goals of home theater are:


Clear dialog
Precise sound localization
Spacious surround
Smooth sound movement
Even tonal balance
Full dynamics
Transparency
Every seat a good seat


----------



## hjones4841

Interesting point that you made about dialog. I would have never believed that bass traps could increase clarity in the center channel, but that is what happened. I originally thought that I had overdone it in mid/high absorption but after listening for a while I think it is just fine.

Dynamics in my system have never been a problem. The speakers are extremely efficient (104db/1watt/1meter) so getting very loud is easy, although at times I wish I had a second sub. I played an old CD of organ music Sunday at high volume and could tell the Velodyne was limiting itself. 99% of the other times it is enough, tho.

The Monsters may have been delayed by Fedex - multiple severe weather events last night between here and Atlanta, including tornadoes. News said that I-20 was shut down both directions about 60 miles east of here; never heard why.


----------



## thewire

hjones4841 said:


> thewire: I meant to ask you what brand/color of black paint worked best for you? Folks at AVSforums like Behr Mouse Ears, but say that it badly shows marks. I used a Glidden flat with a Behr color that Home Depot mixed for me. Color is fine, but has a slight sheen where light from the screen hits it.
> 
> Before I blacked out the whole ceiling, I covered two rows of tiles closest to the screen with Parts Express black grill cloth - looked great with no reflection or sheen, but too expensive to do the whole room.


I switched to Disney "Lamp Black" because the Home Depot in our area said they did not carry it anymore. I had my previous can for them to match which had been the Behr Mouse Ears. I have to keep the paint on hand to touch up the walls if they get dirty or scratched. I went to a paint store and they said they didn't carry black so I looked at Wal-Mart and Lowes, then Home Depot where I found the Disney Mouse ears. I thought it was best so I went with that. I was not bias because I had not researched it. I figured nobody used black but I had forgotten about ceilings and screen walls then. I had not visited the forums for a few years when we had the HT first built. I had a few weeks to get it done with the framing, electrical, walls, HVAC, and so on with help from the construction crew.

I used a grey primer because the walls sucked up the black very quickly and because they were textured it made it more difficult. I used a black light to find places that I missed. I had to apply three coats of the Mouse Ears after the primer. The extra coat was after someone decided to sweep the room.

It's not reflective much, and not enough to cause a distraction in my room. It sucks up alot of light so I had to get some track lighting in the back of the room. That worked out really well because I can aim it down and watch a movie without the room getting fully lit up, ruining the image, or having to bring a lamp into the room to take photos. The photos really make the room 10X more a mess than it is. I seldom take as much time to clean between projects as I used to.


I removed the face of my Helmholtz Resonators for which I will cover in a fabric frame. I reinforced the left and right walls with very heavy wood on the left wall and some 1 3/4" plywood on the right wall behind the panels. I moved the insulation off my stage to the rear corners inside the now...traps. They are about 1/4 full of insulation each. The insulation behind the Monster Traps helps also for the very low ringing, but the mains response is now very sensitive to the back of the room after reinforcing the walls behind the panels and there isn't enough insulation to fix the dip at around 168 Hz. It's not as bad as it was to start with. The response went up 5dB. I added 3 or filters but I forget. I will get back to that later, but the 40Hz dip is better which I am proud to have accomplished today. This is the one that REW recommended. 



















I could not buy the Rane eq. During the last 3 hours people started bidding and the price doubled so I woln't be getting that soon. The person selling has been selling many of them lately so I will keep an eye open. I will probobly get something else besides an eq. It would be nice to eq the center channel.


----------



## bpape

A comment on the dialog...

That actually is one of the most commone 'symptoms' of a room that has too little bottom end control. It's a lack of clarity in the center. It's also that 'can't hear the dialog so we turn it up - but then the effects are too loud so we turn it down' syndrome.

What's happening is that the bass decay time is out of control and the ringing is masking the dialog. People don't realize that male voice can easily go below 200Hz.

Bryan


----------



## thewire

Good analysis. I have tried a matching center channel and I had similar results. I hope treating the front wall helps.

I just noticed that my speaker ports on the bottom were both plugged with foam. That should raise the bottom frequencies some. For some reason my surrounds drivers and mains drivers do not look alike. In bringing the speakers into the room my mains did not match, and I had brought the surround up front thinking by other speaker was a main. I had checked the ports, but I did not check close enough obviously. That could explain the 250Hz ringing in the graphs. With DVE at high levels my speakers did not pass the buzz test at 250Hz. My previous review of the GIK traps still stands as I had that problem prior to plugging the ports, but I will give my impressions of with and without them again.


----------



## hjones4841

Fedex delivered the other two Monsters at 9 this morning - not bad since they only left Atlanta around 3 this morning. I will at least put them in the room tonight. Kinda limited on "play" time after work. Wife expects the system to be ready for the evening TV viewing by 7 p.m.


----------



## hjones4841

bpape said:


> A comment on the dialog...
> 
> That actually is one of the most commone 'symptoms' of a room that has too little bottom end control. It's a lack of clarity in the center. It's also that 'can't hear the dialog so we turn it up - but then the effects are too loud so we turn it down' syndrome.
> 
> What's happening is that the bass decay time is out of control and the ringing is masking the dialog. People don't realize that male voice can easily go below 200Hz.
> 
> Bryan


This may explain something that happened 10 years ago. I had a Klipsch Academy for center channel that I sold (sure wish I had kept it!) and replaced it with a Belle Klipsch (gussied up La Scala). I expected greater dialog clarity with the Belle but actually the Academy was better. The Academy had been on a stand about 18" or so off the floor. 

The Belle is floor standing, putting the bass horn very near the floor. I bet that excites more room modes than the Academy did and could be the reason I am getting better dialog clarity now that I have traps in the room. Interesting.


----------



## thewire

I took some new measurements this morning after after taking the foam out of the left and right speakers. I found some in the back left surround also. That fixed the dip around 168Hz for the left and right speakers. :jump: Here is a decay of every channel. onder: I used a 80dB target by turning down the level in the pre/pro after I calibrated levels with my THX optimizer. The level of the pre/pro after that was -3 for the subs and -3 to -2 for the other channels.

*Left channel*


*Right Channel*


*Center channel*


*Right surround*


*Left surround*
​


----------



## hjones4841

What was the purpose of the foam? Were you using it to change port tuning?


----------



## thewire

hjones4841 said:


> What was the purpose of the foam? Were you using it to change port tuning?


My surrounds used to be on some steel stands and I could hear more lower bass from the surrounds since the ports were at ear level.


----------



## thewire

Here are photos of the new bass traps in the back of the room. I want to add some cherry stained trim. I finished the fabric already but I need to trim off some of the extra.
The holes behind the couches (there are a total of 4 on each) near the subwoofer raised the 40Hz dip and adding insulation to the corners improved the ringing.



















Here is how the traps look right now in the front of the room. I need to put some of my leftover carpet, fabric, reflective material, larger carpet and recarpet the whole areas, or something to hide the holes where my other 2" panels were hung. There is some insulation or something on the wall near one of the holes that have a couple of the screw anchors you can see above the traps.


----------



## keelay

My jaw drops. 

Nice work. Thanks for sharing


----------



## hjones4841

thewire: Please help me understand how to interpret the spectral decay plots. Here is mine with center & sub driven. What am I looking at/looking for? Thanks.


----------



## thewire

keelay said:


> My jaw drops.
> 
> Nice work. Thanks for sharing


Thanks. Action scenes in the HT are starting to be pretty realistic.



hjones4841 said:


> thewire: Please help me understand how to interpret the spectral decay plots. Here is mine with center & sub driven. What am I looking at/looking for? Thanks.


I use spectral decay to look for an even amount of absorption and to compare that with reflections trying to balance the tone. The blue ones at the bottom go up when I treat I null, and they also go can go down when I treat a peak. I study the spectral decay and look for modes nearby when I am treating a null or peak to see how the effectiveness directly related to the nearby modes. When they seperate and the different colors are spaced futher apart then there is less coloration to the sound and it sounds smoother. If there are valleys or peaks that are not falling directly bellow previous ones above that the bass does not feel right as it decays away.


----------



## thewire

Here is an example of decay that does not sound smooth, and that does not feel right.


----------



## thewire

I picked up four things of R30 unfaced, paneling nails, and trim for the rear traps from Lowes. The trim has a smooth curve to it. The insulation should allow me to get the concrete off the rear traps, and remove the plywood in the ceiling in the back of the room above the center/rear wall, then fill the corner there. I need some around the tri-corners in the back of the room also. I hope that this will improve the surrounds some. If the rear corners are anything like the front corners, it should trap some around 90Hz.


----------



## thewire

Here are the new results after putting in the insulation. I had some extra to place above the right subwoofer where there was none. 










These were the filters.










The intro to Star Wars EP3 at reference level sounded fantastic but the track lighting was shaking around like a leaf. I will do my best to secure that. We will be replacing the hole in the ceiling where I have taken down the hush box and the projector still is hanging with more Ceilume Ceiling Tiles/Back Panels, and insulation.

The surrounds seem to have improved but it looks like my single 2" 2X2 panel that I forgot was in the corner next to my right surround is helping more than treating above the ceiling helps.

*Surround right*


*Surround left*


*Center*
​


----------



## robbo266317

That is getting very smooth, you must be impressed with the results. :yes:


----------



## thewire

robbo266317 said:


> That is getting very smooth, you must be impressed with the results. :yes:


I think that I must spend at least a few hours in the HT listening to music and it sounds even better than before. The room sounds less bright than it did now since I have completed putting up the fabric on the rear traps. 

In an odd note I found my settings in the pre/pro to be different than I setup last time, or at least wat I thought I set them to. :huh: The subwoofer level was -5 and the mains were not adjusted like I had them. This has happened before that I can remember. I will need to check a manual and see if I can figure out the memory button. It could be I made so many adjustments I forgot.

Right now I would give the sound in the room :4stars:


----------



## thewire

It could also sound less bright since I took all the concrete out the back of the room. :yes:


----------



## thewire

There is no cutting of OC 705 required. :whistling: It would help if I could remove the old screen frame which I might end up doing. That would allow it be inserted with a friction fit.










Here is one of the rear traps being built. I had an espicially difficult time with the left side because my stapler began to jam no matter if I put in newer staples or not. It was also difficult on the left side because the jigsaw is missing the peice to hold it straight and the angle of the blade was not ideal for cutting angles on that side of the room when I needed to keep the blade angled away from studs. At least the drill is fixed, but we did get a new cordless also. The trim does not match perfectly but it was as close to deep cherry as they had. I am wondering if I could not spray a transparent red over it to make it look cherry. I have never stained before but I know that it is difficult to match a stain. Maybe I should not worry about that. At any rate I got them cut pretty close to being flush but I'm sure I will do better without having to worry about the straight cuts and fabric on the next one. I might need more trim to finish, and I am debating whether to cut my losses and return what I have then stain some instead. I had not realized that the cut edges of the fake wood would look like unpainted cardboard.


----------



## thewire

I had to do more corrections. Everytime I change something I have to go back and change 10 times as much. 


Took the kraft paper off insulation in the stage & uncompressed it some
Moved more 2" panels over the stage
Covered the front wall with OC 705 2"
Moved the Pillar Traps away from the corners some & removed insulation under them
Moved speakers away from the listening position inches
Didn't equalize bellow 50Hz

Hope this looks alright. This is the left speaker.










My right speaker shown in this graph I had to go back and take extra absorption out from behind the speaker that I added inside the cabinet. :whistling: This shows just how sensitive these graphs are to my speakers from around 7' away pretty well. 










I fixed that so hope it looks better and more like the left speaker next time I measure.

Here is a new RT60 graph (interpret at your own discretion). The area above 1Khz went down in level after removing the kraft paper and moving the speaker and not just after adding the 6 panels of OC 705, which I had done earlier.


----------



## hjones4841

I admire your determination (and energy level!) in getting your room treatments right. You have me thinking about treating my ceiling after all.

In a previous post you mentioned track lighting. What brand/style did you use and do they rattle? I have recessed cans in the ceiling that supplied enough light until I blacked out the ceiling. Some track lights around the room perimiter would help.


----------



## bpape

I would strongly recommend against track lighting - exactly for the reasons that are being described here. Just their basic design and flexibility (advantages) make them inherently non-rigid. I had track lighting in one house many years ago and whenever I'd get the sub up and moving, not only would I get buzzes and rattles, I'd pop bulbs unless I used the rough service ones.

Bryan


----------



## thewire

hjones4841 said:


> I admire your determination (and energy level!) in getting your room treatments right. You have me thinking about treating my ceiling after all.
> 
> In a previous post you mentioned track lighting. What brand/style did you use and do they rattle? I have recessed cans in the ceiling that supplied enough light until I blacked out the ceiling. Some track lights around the room perimiter would help.


Bryan is right they are not good for HT. When I shopped for track lighting I had a sales representative allow me to climb the latter and physically shake each of the lighting to test them for rattles. The ones that gave me least rattles were the style I choose. The ceiling joist are all decoupled from the walls and they are secured further by furring strips that are wedged from the joist into ridges that are on the steel ceiling. That helps prevent the entire joist from physically bowing around with sine waves and aids in the perfomance of my ceiling tiles but does that help the plastic track lighting? Nope. I have placed a small amount of cardboard under them, but the fact that there is loose tile between the wood and the parts attached to the track lighting gives them no support in those areas. What I found shaking was the parts that contain the bulbs, but this is something I notice sitting in the rear of the room, not the front of the room. I need to be sitting under them because otherwise I have not heard it up until now. My sconces are caulked to the walls except in the front where there is carpet behind them. I tried all forms of lighting before I got the track lighting. Lamps, flourecent lighting, night lights. Some battery powered LED lighting would be best but it isn't going to fully light my room, and it isn't cheap. That's way low down at near 20Hz that shook the track lighting. It isn't sound I'm able to hear well. It is mostly felt.

I got mine at Lowes. Here is a photo of it.










I have an example here with what happens when I remove treatments from the room. Removing the extra absorption behind the speaker in the cabinet made the right speaker worse, so I am going to try and see what I can do to improve the results more. As I removed all the treatments, then began to add them, the room began to sound larger and bass became more easy to hear. It also sounded like I was adding larger speakers.

Room treatments where they are.









Removed 2" panels from the front of the stage.









Removed a pair of 2" ATS panels and 6 GIK 244's from first reflection points.









Removed the pair of GIK Pillar Traps. Ouch!









Removed the pair of GIK Moster Traps.









Removed the 6 panels of OC 705 from the front wall.


----------



## thewire

It looks like adding some Rockwool 60 to the speaker cabinets moved the resonance down near 100Hz. I noticed that the response looks more flat with the wires reversed from however they are (not sure at this time). I thought the idea is to get the crossover area the highest in SPL but this looks better to me. There were low frequencies that were effected with my mains ran in full range mode with the subwoofers getting double bass but perhaps that was normal. These might be the correct results.

*Left + subwoofers*










*Right + subwoofers*










edit: the center channel was added back in the room for these also. Mic was pointed at an angle for these also. Can't wait to start watching movies!


----------



## hjones4841

thewire said:


> I switched to Disney "Lamp Black" because the Home Depot in our area said they did not carry it anymore.


Is Lamp Black a Behr color? I may pick up some cheap ceiling tiles and try painting them. I don't have a spray gun, so I will either have to roll it on or use flat black spray cans. The old tiles were USG Radar style. They had holes for "acoustics" and never would paint well. If I can find some smoother surface tiles, then painting may work OK.


----------



## thewire

hjones4841 said:


> Is Lamp Black a Behr color? I may pick up some cheap ceiling tiles and try painting them. I don't have a spray gun, so I will either have to roll it on or use flat black spray cans. The old tiles were USG Radar style. They had holes for "acoustics" and never would paint well. If I can find some smoother surface tiles, then painting may work OK.


Those tiles are for things like classrooms. I would recommend some Sonex ceiling tiles.

http://www.sonex-online.com/SONEX Ceilings.htm

The Lamp Black was BEHR Premium.


----------



## hjones4841

thewire said:


> Those tiles are for things like classrooms. I would recommend some Sonex ceiling tiles.


Shhhhhhh... Recommending foam acoustic products will get you banned from this forum for LIFE:bigsmile:

That stuff is way too expensive for me. Painted regular ceiling tiles with R30 over it wil be fine.


----------



## thewire

hjones4841 said:


> Shhhhhhh... Recommending foam acoustic products will get you banned from this forum for LIFE:bigsmile:
> 
> That stuff is way too expensive for me. Painted regular ceiling tiles with R30 over it wil be fine.


:hide: Regular tiles will be better than drywall, but I thought you already tried that and had problems with them rattling. Are you going to glue them?


----------



## hjones4841

Well, something is still rattling up there when I do LF sweeps - either the grid or the sheetrock "tiles." 

The sheetrock tiles just don't look very good - the beveled edges where the tape and mud go in normal use are up against the grid and are quite visible. Did not bother me at first, but now it does. Plus, I need something acoustically "porus" for the R30 to go on top.

Can't glue some of them due to needing access to pipes, otherwise the whole ceiling would be solid sheetrock. I am toying with building wood frames instead and covering them with grill cloth - Ethan's site has photos of a studio done that way.


----------



## thewire

hjones4841 said:


> Well, something is still rattling up there when I do LF sweeps - either the grid or the sheetrock "tiles."
> 
> The sheetrock tiles just don't look very good - the beveled edges where the tape and mud go in normal use are up against the grid and are quite visible. Did not bother me at first, but now it does. Plus, I need something acoustically "porus" for the R30 to go on top.
> 
> Can't glue some of them due to needing access to pipes, otherwise the whole ceiling would be solid sheetrock. I am toying with building wood frames instead and covering them with grill cloth - Ethan's site has photos of a studio done that way.


That's the problem with the ones I see at the local hardware stores. They are not porus. I was doing my best to find you some Mineral Wool Ceiling tiles but I am having trouble finding any. You could also cut your own out of Mineral Wool and cover it with fabric. If I remember right it was around $300.00 if I wanted to cover my entire ceiling with Rockwool 60 2". This is a cost effective way to have tiles and I have seen members on this site with mineral wool ceiling tiles but they were able to get them easy from the location they lived at. :yes: The bass passes through my tiles like they are nothing. They are after all close to paper thin PVC.


----------



## hjones4841

I am really beginnng to like the idea of making ceiling tiles from mineral wool, 703 or 705, cover them with black cloth and line the perimeter of the room. Then I could use the same black cloth and cover the remaining sheetrock panels to match.

A question about cutting various materials: I will need to cut 1/4" off each dimension to fit into the grids. Which material will be the best for that? I heard that mineral wool panels are kinda brittle. Would 703 or 705 work better in the long run? Might be worth the extra $s to put up something that 1) works and 2) wont' sag over time.


----------



## thewire

hjones4841 said:


> I am really beginnng to like the idea of making ceiling tiles from mineral wool, 703 or 705, cover them with black cloth and line the perimeter of the room. Then I could use the same black cloth and cover the remaining sheetrock panels to match.
> 
> A question about cutting various materials: I will need to cut 1/4" off each dimension to fit into the grids. Which material will be the best for that? I heard that mineral wool panels are kinda brittle. Would 703 or 705 work better in the long run? Might be worth the extra $s to put up something that 1) works and 2) wont' sag over time.


I'm not sure why OC would not work just as well. I think that it was just recommended to use mineral wool because it is just as effective as using the OC for the ceiling. I forget exactly how to apply the fabric but I think that spray adhiesive might work. The mineral wool I am thinking of comes with a paper facing on it. I did a search in google and had a hit to the Roxul site but it did not show a picture of it. When I did a search for faced Roxul I also got hits for some but they are sites in the UK and china. 

One idea however that may work. onder: I acutally wrapped Roxul in newspaper then I tapped it so that I could wedge it between my projector and the ceiling without worrying about it crumbling. I'm sure you could spray some adheisive on some 2" Roxul Rockboard (this stuff I have to cut with a hacksaw) and put some newspaper on it, then put some fabric on it and glue that somehow if you are worried about it crumbling. :scratch: I should have paid better attention to that part in THX training. :sad:


----------



## bpape

The idea with the drywall is to maintain mass, minimize high frequency absorption, and still allow the cavity above (insulated) to provide some bass control. 

Sonex is way too expensive and also is very high frequency absorbant. Standard firmer ceiling tiles faced with something like FSK and then covered in cloth will be quiet, high frequency reflective, and allow good bass control with just pink stuff up above.

Bryan


----------



## hjones4841

OK, part 1 is done: Joann's on-line has a 40 yard bolt of Bengal burlap 10oz, 35" wide on sale for $72 plus tax and shipping (about $90 total). I just ordered one bolt in black, which will almost do the whole ceiling (won't quite do the rear-most row, but I can buy more by the yard). I plan to wrap the 35" width around the 24" dimension of the sheetrock pieces in the center of the room and then pick up some lay-in tiles for the perimeter and use the burlap around them as well. 

That price is more than re-painting the existing sheetrock pieces, but I think that the burlap will cover the beveled edges and look better. Plus, it should not have any sheen, which is a problem with the existing paint. Having the fabric around the edges of the sheetrock may help prevent rattles as well.

Bryan: I suppose there is no need to put R30 above the sheetrock (5/8") panels since they won't pass bass very well, right? Also, I should not need to put R30 above the tiles in the center of the room anyway since bass peaks will be around the room perimeter, correct?


----------



## bpape

Well, that's a tough call. While it won't pass it as well as a ceiling tile, it can still be a resonating cavity. 

If it were me, I'd likely try it at least across the front of the room since you have most of your treatments now in the rear.

Bryan


----------



## hjones4841

Bryan: Posterboard should be an acceptable substitute for FSK for the ceiling tiles, right? I thought it would provide a better, no wrinkle surface to glue the burlap to. Also, I could use black posterboard to make sure that the white tile does not show thru the burlap.


----------



## bpape

That should work OK.


----------



## thewire

Since my subwoofers don't have a limiter or anything, would one of these help protect my subwoofers, or prevent low frequencies from possibly harming my projector, or burning out bulbs in my room, shaking track lighting, etc?

http://store.hlabs.com/pk4/store.pl?view_product=12


----------



## robbo266317

Good call.
I hadn't considered the fact that the bass would shake the filament, potentially downgrading it's lifespan, or even worse, causing catastrophic failure!


----------



## thewire

robbo266317 said:


> Good call.
> I hadn't considered the fact that the bass would shake the filament, potentially downgrading it's lifespan, or even worse, causing catastrophic failure!


I'm almost 100% certain it is what has caused my projector to stop working. The second bookshelf I had in the back of my room was starting to fall apart so I took it out before it was destroyed like the other one. I'm very nervous about putting this new projector right above my subwoofer in the back of the room.  I am going to try and build the shelf like a tank but I don't exactly have a plan how to do that yet. I don't think it would be covered under warranty if my new pj was destroyed. I have never burned out any track lighting bulbs but the ones in my sconces go out around twice a month. The dishes in the kitchen shake on the other side of the concrete wall if I leave the HT door open and the candy counter in the lobby is lucky to be intact. I burned out a light on the deck outside once when I turned that on during some movie previews.

edit: I have a couple of subdudes left that I might use for the pj.


----------



## thewire

This is the back row LFE response with the master volume at 0.










This is the back wall where the projector will be. It looks like the mic could hear the track lighting hum possibly. I can't say that I ever noticed that unless I dimmed them alot and listened very close. It might be because the mic was hanging next to Romex that powered them.


----------



## thewire

I went and ordered one of those subsonic filters to see what I can do. My subwoofers are suppossed to be rolling off at 35Hz to be flat to 20Hz so it will be interesting to see what a high pass filter will help accomplish. My amps are flat from 20Hz.


----------



## bpape

You can try it but it kinda defeats the purpose of a good sub. Build a decent hushbox around the PJ that's solid and then have a suspended platform (like a board on foam or something) inside the box. That will damp the low frequencies coming from the box itself and still isolate the PJ from airborne waves somewhat.

Bryan


----------



## thewire

bpape said:


> You can try it but it kinda defeats the purpose of a good sub. Build a decent hushbox around the PJ that's solid and then have a suspended platform (like a board on foam or something) inside the box. That will damp the low frequencies coming from the box itself and still isolate the PJ from airborne waves somewhat.
> 
> Bryan


Thanks Bryan. My old hush box placed above the subwoofer would cause a dip of around 5dB around 40Hz. I will see what we can do otherwise with different materials. The subwoofers don't have usuable response bellow 18Hz.


----------



## thewire

It looks like a ceiling mount would only run me 30 dollars and shipping. That is near five times cheaper than my CRT ceiling mount was. Amazing! I did not realize these were so cheap. I may end up doing that instead. I also don't see much option for the back wall except to hang a curtain, blanket, or new panels. I have never seen anyone successfully build a rear wall projector booth (without being in a next room) with results that worked for acoustics. I have only seen them go back to have it corrected by the pros, something I would like to avoid having to do myself, or having to hire someone to correct later. It looks like I still have enough fabric that I will need.


----------



## hjones4841

I don't know what projector you are going to hang, but I would be very wary of a $30 ceiling mount. The good ones (Chief, Peerless) are $150-170 or so. Even at that price, there are really bad ones. When I got my Sony PJ in December, I ordered a mount from a place in Canada - sure looked great on the web. When I hung the projector it was very wobbly. I ended up modding my old NEC mount and re-using it.


----------



## thewire

hjones4841 said:


> I don't know what projector you are going to hang, but I would be very wary of a $30 ceiling mount. The good ones (Chief, Peerless) are $150-170 or so. Even at that price, there are really bad ones. When I got my Sony PJ in December, I ordered a mount from a place in Canada - sure looked great on the web. When I hung the projector it was very wobbly. I ended up modding my old NEC mount and re-using it.


It was ebay item 200315704484. It is for a BenQ W5000 projector. I was checking the sellers feedback and the people that bought projector mounts seem happy with them. It's a little strange that the seller says the other people are selling ones made out of a garage and the ones that I find from other sellers cost $150.00. I did not find $14.00 ones. :huh:


----------



## hjones4841

thewire: Do you have any type of tactile transducers? I am ordering Berkline recliners and really cannot justify the cost of Buttkickers. Not sure my back can take much vibration, but wanted to try something. So, I ordered the less expensive Aura Pros from Parts Express. I read that they have a resonance of 40Hz that needs to be tamed - guess that is what I can use the other BFD channel for.


----------



## bpape

Go old-school. If you want to be rocked, buy enough sub to do the job. Butt-kickers are a cheat. If you want bass get the right sub(s).

Bryan


----------



## thewire

I don't think that I would mind some butt-kickers but it's very low on my priority of things to get. I'm much more interested in getting some newer surrounds that I could mount on the wall for example. As far as low sounding subwoofage goes I am yelled at and ridiculed for any bass that is felt in the HT more than a rumble. :sad: They yell "that is ridiculous your gonna blow your speakers!" or "loud enough?!" or even "whooooaahh" and meanwhile I'm just trying to enjoy the movie. :shh: If I didn't watch 90% of the content with my folks when they are visiting (they are in late 50's) then I would have large and powerful subs :flex: ...with low distortion :innocent: and my room would look very different. :sob: There would most importantly be less seats to worry about thus giving me alot more room to work with. Beggers canno't be choosers however. My hopes are that I will have a place of my own but I don't expect that the room will be as large as this one. I'm amazed that I am at least allowed to watch movies at reference level, until the seats start to move. :thud:


----------



## hjones4841

bpape said:


> Go old-school.


I agree completely, but I have the amp and crossover already, so the price of admission is at the "toy" level. When I tire of them, there is always the kid down the street:bigsmile:

BTW, the chairs are coming from RSH - glad to support a forum supporter.


----------



## hjones4841

thewire said:


> (they are in late 50's)


Hey, watch it, Bub:foottap: Us old folks like our subs, too:jump:

Watch the episode of Home Improvement called "The Look" sometime. That is what I get from wifey when she walks into the HT - that turn that thing down look:gah:


----------



## thewire

hjones4841 said:


> Hey, watch it, Bub:foottap: Us old folks like our subs, too:jump:
> 
> Watch the episode of Home Improvement called "The Look" sometime. That is what I get from wifey when she walks into the HT - that turn that thing down look:gah:


They already enjoyed subs, perhaps too much. They did alot of clubbing and used to dance right in front of the stacks of 18"s. :hsd: Not that they do not enjoy the subwoofers, just perhaps maybe a little critical of bass the way it is nowadays. They thought UB571, The Matrix Trilogy, and such movies were fine but when you get into some like War of the Worlds, Master and Commander, The Hulk, for example it is :surrender:. The comment I got from that last demo of the start of Star Wars EP3 was "it's got kick".

Something I learned was that to save valuable headroom and decrease the load on the driver was to limit frequencies for which were not needed. The THX subs are suppossed to have a 12dB Octave roll-off at 20Hz. That is not bad in my opinion and with no limiter on them I think I could probobly shoot a golf ball across our cove with one. :bigsmile: I don't think that people realize just how much a driver will not move with a limiter on.:whistling: 

I was a fan of that show. I also read Tim Alens book.


----------



## thewire

I am in the proccess of getting the new projector installed and I have a question. The track lighting is being taken out and could be relocated somewhere because it can't be located right next to the pj. I was thinking of installing it near the rear row or placing it on the back wall further away. I could also attach some power cords to them and wire an outlet, that way I could remove them from the room if I wanted like if I was not working in the room on something. :dunno: As it is they are more like work lights, less like lighting might be in a mulit-purpose room. I will see if they can stay where they are first, but I thought I would ask.


----------



## thewire

I forgot I already asked that.... Sorry, I will just remove the lighting out of the tracks when I am not using it.


----------



## thewire

Here is a photo of the progress on the front wall. I may be ordering some more tiles this week and I did not have enough fabric, so I will probobly order some of that also soon. This is a screen shot from "The Terminal" (2004) on DVD.


----------



## hjones4841

I see that you have your new projector installed. Happy with it?

For your ceiling, I am having good luck with the R30 if there is a way to add it to your room. I am now getting reduction in ringing in the 30-40 Hz range. R30's relative lack of absorption in bass is being made up in square footage.


----------



## thewire

hjones4841 said:


> I see that you have your new projector installed. Happy with it?
> 
> For your ceiling, I am having good luck with the R30 if there is a way to add it to your room. I am now getting reduction in ringing in the 30-40 Hz range. R30's relative lack of absorption in bass is being made up in square footage.


So far so good with the projector. It came with 1 hour on the bulb. One of the downsides with DLP besides needing a well light controlled enviornment is that the bulbs need to broken in 100-200 hours. Many custom installers will actually run the projectors in the show room before installing them for customers. After my calibration, I have contrast down to 41, and brightness at 49 with 0 manual iris for the photo I took. I will do some further calibration after the bulb is broken in with DVE, then decide if I am trully keeping it. I really don't think I could deal with an LCD, LCOS, or other technology, and so far the RBE is pretty minimal, but it does seem to an issue with some material. Only time will tell. The contrast is now better than my CRT was, with the warn out 6" tubes that it had. The blacks now appear to be darker without the hallows and horizontal white lines across the screen that I had. The resolution in my photos still looks about the same, but my new projector is also sharper since I never had the older projector proffessionaly calibrated. 

Screen shots don't really do justice much but you can observe the difference of my older projector versus the new one (how it is so far) here with a still from "Transformers" on HD-DVD.

*NEC 6PG+ (1080i)*










*BenQ W5000 (1080P XA2 in auto for both Hz rate and pull down)*










Here is another from "The Terminal" I took recently. I'm using the Reon upscalling in the XA2 because my RGBHV cable does not reach the projector right now.








The store was out of R30 last weekend but I hope to get some more this weekend.:yes:


----------



## hjones4841

As you know, RBE is more visible to some folks than others. My previous projector was a DLP -- NEC HT-1100. My son and I could see rainbows when I first got it; my wife never did. Later on I did not notice them myself at all unless I forced a rapid eye scan from side to side. I now have a Sony VPL-HW10 with their variation of LCD - very pleased with it.


----------



## thewire

hjones4841 said:


> As you know, RBE is more visible to some folks than others. My previous projector was a DLP -- NEC HT-1100. My son and I could see rainbows when I first got it; my wife never did. Later on I did not notice them myself at all unless I forced a rapid eye scan from side to side. I now have a Sony VPL-HW10 with their variation of LCD - very pleased with it.


I would love to have a VPL-HW10, although if it does have the .1 pixel adjustments that I am reading about that is way overkill. Your up in the high-end projector class where they are comparably as close to a DLP or the king of projection a CRT. An advantage of the new projectors like the VPL-HW10 is not a huge upgrade difference from say the VP-60, but I did hear they offer better compatabilty, and are more reliable.


----------



## thewire

I have had the projector up and running for quite awhile these past few days. I began to become impressed with the image after 30 hours so I decided to do a calibration with DVE setting the color levels and the gamma to the appropriate settings. Now approaching 40 hours I have to say that has to be plenty of time for me to be able to say.... how great the theater sounds! I'm very satisfied with the way the theater is sounding so far thanks to GIK acoustics (other treatments) and REW! :T I did some basic calibration of the levels using an optimizer and it sounds quite fair compared to other calibrations I have done in the past. Even the THX Amazing Life trailor sounds clear and undistorted. I highly recommend anyone that is thinking about the Pillar Traps get them not for just their great looks, but because they are really excellent performers. Back to more movies. :clock:


----------



## bpape

Thanks for the kind words. You deserve a lot of the credit as you've spent a lot of time experimenting and getting things just right.

Glad you're enjoying it.

Bryan


----------



## hjones4841

thewire said:


> how great the theater sounds!


Glad that you are pleased with the results of your work. Nothing like having a project go well (to counter all the times they don't:hissyfit.

I plan to finish my ceiling treatment this weekend - the rest of the burlap came in so all I need now is some time.

By far, the most audible improvement came from putting the Monster traps in. The benefits from the ceiling traps are certainly showing up on the waterfalls but they are not as audible as what I noticed when the first 5 traps were put in the room. I suppose that means that the most audible ringing was suppressed early in the treatment process and what I am getting is now icing on the cake.

I am having thoughts about adding another sub sometime, but no definate plans right now. A DIY IB or LLT would be fun, but also physically challenging for me. I will either watch for a good used 18" Velodyne (no way on the $5k new Velo prices now) similar to the one I have now or maybe try a Hsu or SVS later in the year.


----------



## hjones4841

thewire said:


> The store was out of R30 last weekend but I hope to get some more this weekend.:yes:


Did you start working on the added treatments? Are you putting them on the ceiling?


----------



## thewire

hjones4841 said:


> Did you start working on the added treatments? Are you putting them on the ceiling?


Not yet but they are ordered. When I ordered the back panels for them I have to order a case of what I think was 30 of them. I thought well, I have to have those so I went and got those also. I ordered yet another pair of GIK 244's also which will arrive soon. I have the fabric here already for that to be installed also.


----------



## thewire

I installed the new 244's on the back wall and plan to equalize the subwoofer soon, but I ordered the wrong color tile which by mistake was the pic used for my last order, so I will have to wait until I have returned the wrong ones for new ones. It would not make a decent photo until I could get the ceiling up next to the back wall finished but I will try and get some photos of the installation eventually.


----------



## thewire

They have corrected my order for the ceiling tiles near a week ago but they still have not shipped.  There is a roll of insulation I have had for what seems like forever sitting out waiting to be put in and I will pick up some more. 

On another note I have ordered a Panasonic LX3K camera with a 6 hour battery and 2G memory card that they said would arrive in about a week but that is being shipped to another location so it could take longer to receive. I should be able to get some much better photos then.


----------



## thewire

The new tiles will be here tommorow and I will try and get some new measurements then when I am done placing those in. I might need to pick up another roll of R19 as well.


----------



## hjones4841

Glad you are making progress.


----------



## thewire

I went and ordered a Sigma DP2 camera instead of the LX3K and that should arrive in 1-3 months. It's good for shooting in low light situations. :nerd:

The tiles have been here for quite awhile but I have not got around to installing them yet. I will do that when the new camera arrives. I have not redone the equilization filters yet and that really needs to be done but I almost feel like it's measuring a final measurement which goes against my morals because a pro with $$$ gear should do an official measurement. I do not have the extra cash laying around for doing that but if I did I would. :innocent: I thought I would just say the tiles arrived for now and checking them they are the right ones this time. When I do install them I will try with the single R19 roll since it could be enough.


----------

