# Acoustic Treatment Phase 2



## Peter Loeser

I caught the upgrade bug this year and decided to go from 5.1 to 7.1 to 9.1 to 11.1 :gulp: and buy or build some larger subs. I sold my 7.1 pre/pro and one sub and bought some extra surround speakers. Long story short, I am now wired and "speakered" for up to 11.1, but have not yet purchased a new receiver or subs. I am stalled partially due to funding but also due to the realization that I need to improve my room acoustics first, or I may just be wasting money on equipment upgrades. I think now is the best time to do it, but I want to throw a few ideas out there and get some feedback before I start. For reference, there are some fairly recent photos of my room here (latest photos toward the bottom). The panels on the side walls are 2 inch thick OC 703 and they are flush mounted. The placement is based partially on aesthetics, and partially on the first reflection points of an earlier seating arrangement. To give you an idea of my starting point, I have included some REW measurements below.


*Measurement Graphs* 



*The graphs represent response from several different system configurations (including several different subs in different locations, several different receivers/processors, and a few different main listening positions). These measurements were all taken without EQ or room correction applied. The side wall panels were installed before all of these measurements.*

Full Range Frequency Response
 

Bass Only Frequency Response
 

*The waterfalls correspond to four of the FR curves on the graphs above*

Waterfall 1
 

Waterfall 2
 

Waterfall 3
 

Waterfall 4
 




*Based on listening/measuring, my target areas are (in this order):*

1st - 30-60Hz
2nd - 100-200Hz
3rd - 200-1kHz (if it is still an issue after treating 1 & 2)


*So here are some ideas I'm kicking around...*

1. Double the 2" panels on the side walls (2 panels each in a 4" deep wood frame) and mount them with a 2"-4" air gap to the wall (meaning the frame is open front and back).

2. Add diffusers between existing panels on side walls. My initial thought would be the 2'x2' DIY wooden QRD "skyline" diffuser panels - 4 total.

3a. Triangular bass traps in the rear corners (can't do front corner placement due to existing doors). I'm thinking DIY, either mineral wool or pink fluffy, probably about 4' tall with a 24" wide face.

3b. OR move the side wall panels closest to the back wall into the back corners and make them thicker (i.e. like step 1 - 4" or 6" thickness) for bass trapping.

4. Add damping to the 1st ceiling reflection, probably 2 or 3 panels, 2" or 4" thick, something similar to what I end up with on the side walls.

5. Damping/Diffusion behind front speakers? This is a maybe since I plan to cover the entire front wall/doors with heavy curtains, mostly for aesthetics/light reflection.


Ideally I would have the budget and time to do all of these, and maybe someday I'll get there. I guess what I'm looking for in terms of feedback is - if I could pick two, maybe 3 to do first, which will give me the best bang for my buck? I'm thinking 3a, 1, and 2 in that order to start. I assume triangular corner traps are my best bet for the 30-60Hz range. Will they be effective in the back corners if my subs are at the front of the room? Will option 1 improve my 200-2kHz response, or will the difference be negligible?


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## bpape

*Re: Acoutic Treatment Phase 2*

5a. Damp the entire front wall to address reflections from the surrounds messing up the front soundstage.

In the rear, stay with the triangular chunks. Better performance for the same $$$ as 6" straddling. 

Side wall panels - going to 4" is good. Probably a 2" gap is fine. 

I would do side wall and corners first. Diffusion probably last.


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## Peter Loeser

*Re: Acoutic Treatment Phase 2*

Thanks for the feedback Bryan. When I get around to treating the front wall, will 2" thick panels be sufficient?


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## bpape

*Re: Acoutic Treatment Phase 2*

Generally speaking, yes. 2' will be fine. You can go thicker but I'd want to know what else is going to be going on in the room overall.

Bryan


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## Peter Loeser

*Re: Acoutic Treatment Phase 2*

Thanks again Bryan. I think I will start with options 3a and 1 as suggested, and decide what is needed from there. Front wall treatment would not be too difficult, and sounds as though it would be worth the effort. That may be phase 3 for me.


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## Peter Loeser

Gave it some thought and kicked around the idea of building my own bass traps, but the longer I think about it the more he GIK tri-traps look like the way to go. I ordered a couple fabric samples this week, to get the color right. This will most likely be the next purchase for my HT. After that I'm going to get some pre-built 4" deep frames and 6 more 2" panels to expand my side wall absorption panels.

Bryan - what's the best way to mount tri-traps to the wall (sheetrock)?


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## bpape

Tri Traps have no provision to mount. They're designed to sit on the floor and stack. If you need to get them up, you'd just need to build a small corner shelf for them to sit on.

Bryan


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## Peter Loeser

Old thread here but I'm finally ready to pull the trigger on some acoustic updates. I want to get this done correctly before the subwoofer and Atmos upgrades I'm hoping to do possibly early next year. I'm going to forgo the DIY option and get GIK 244 panels for the side walls first and re-evaluate. Next step will be tri-traps in the back corners if needed.


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## bpape

Both are good things to do. Which first is personal preference.


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## Peter Loeser

Ordered 3 sets of 244 panels this morning. I will follow up here once I have them installed.


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## Peter Loeser

My panels arrived last week and I installed them over the weekend. Installation was pretty easy. I used two screws with Sheetrock anchors per panel. The only real time consuming part is measuring for screw/hook locations on the wall and keeping them lined up and level. Each panel hangs with a wire across the back like a large picture frame (which also allows for easy height tweaking). As you can see I have three panels on each side wall positioned to catch first reflections from the left, right, and center channels for all seating positions. I kept my 2" thick DIY panels and have them stacked in the back corners to see if they'll help a bit with bass trapping as well. I have not had a chance yet to do any listening or measurements but I plan to do that pretty soon and post results here. Stay tuned! In the meantime, enjoy some poorly lit phone camera pictures!


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## Peter Loeser

Ok, I've hung my new panels, moved some things around and taken some new REW measurements. With reference to my original post, I'm still focusing on my first target (30-60Hz range), even though it's not the only issue.

First - what I've changed. As stated above, I mounted 6 GIK 244 bass traps and moved my existing 2" panels to the back corners (stacked 3 deep for 6" thickness in each corner). I currently also have the privilege of borrowing a pair of Chane SBE-118 subs for an upcoming review, so I decided to see if dual subs could help with some of my problems. Turns out it helped more than anything I've tried so far, but I'm not convinced I'm anywhere near done with acoustic treatments. After trying a bunch of different configurations and EQ settings, I settled on placing the subs in the back corners of my room, and adding a boost at 18Hz on the Dayton amp. Below is a comparison of the single sub responses (various locations in the room) to the dual sub response I'm getting now.


*Measurement Graphs* 




Single sub, 2" panels (x6)
 

Dual sub/rear corners, GIK 244 (x6) plus 2" panels (x6)
 

 



The good news: response from 20Hz up to almost 70Hz is about +/-3dB (compared to +/-10db worst case before). It sounds much better at the MLP too, of course.

The not great but not surprising news: this confirms my suspicion that dual subs are basically a necessity for me.

The bad news: issue #2 (100-200Hz) response looks awful, if not worse than before. Moving the mic around the seating area didn't make any major improvements in this area. I had anticipated the 244 panels to improve response in the 100-300Hz range a bit more than I'm seeing. How much do panel quantity, panel placement, speaker placement, and seating placement effect response in this region? I guess what I'm getting at is, do I need to add more panels/bass traps or is the room arrangement at play? Just to clarify, I have not bothered trying to EQ the big dip. I have tried 2 or 3 different speakers with similar results here too, which makes me think it's almost completely a room issue. I know room correction and EQ is always an option, but I personally want to get the room as good as I can without the use of EQ.


edit: I should add that I have tried different sub crossover and phase settings as well, and nothing made much of an improvement without messing up response above or below. I also added a waterfall graph for the current setup.


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## bpape

Looks to me like the bottom end of your current trough might be a phase issue between mains and sub(s). Try reversing the phase on 1 then on both of them and see if you can at least get a part of it better. Above that it's likely boundary related phase issues (SBIR).


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## Peter Loeser

Bryan - thanks for your quick response last week. I had some time last night to move things around a bit and take more measurements.

First, I tried reversing polarity on just one and then both subs. It did nothing to help the trough from crossover up to about 200Hz, and made things below 50Hz much worse. I played some more with the crossover settings and PEQ but couldn't get even marginal improvement in that area.

Since you mentioned SBIR, I took a quick look at GIK's page on the subject. I tried moving my loose 2" panels behind and beside the main, in the front corner, and on the side wall at the front of the room. It didn't seem to help much, but I wasn't being very scientific about it. Throughout the process I have tried two different types of speakers for the mains and a few different mic positions within the seating area.

After a while of that, I took measurements of the subs alone and the speaker alone. The sub-only curve looked very good up to 120Hz or so. The main-only curve still had the awful dip. I tried moving the main side-to-side a couple feet, and even about 2-3 feet into the room (very unpractical placement) and it did change, but I wouldn't call it better. See the graph below for before and after. The pink trace is the normal spot, pretty close to the front wall, on either side of my TV. The blue trace is probably about 30-36" out from the front wall, and probably about 2-3 feet from the mic.

 

I'm coming to the conclusion that my room dimensions combined with speaker placement are causing some major issues. Is it too much to correct with more bass trapping? I don't have much freedom with placement of the main speakers. Sub location is pretty flexible, but they seem happy in the back corners.


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## bpape

If the sub is OK and the mains are bad, then either positioning or you need to work with thicker panels on the front wall or side walls pending where it's coming from. It's possible that you had problems in that general range for both front and side that were somewhat cancelling. When you fixed one, the other was no longer cancelled. It happens sometimes. Need to try something much thicker than 2" to try to fix that on the front wall.


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## Peter Loeser

Even with the improved response of the subs being placed in the back corners, I wasn't satisfied, so I did some more rearranging. Turns out placing on sub at the center of the front wall and the back wall improved response even more. Still not perfect, but much better. Two PEQ filters and I'm a pretty happy camper considering what I started with. Too bad these subs aren't mine :sad:

Anyway, here is the resulting response up to 200Hz. Target response was around 75db with 20Hz being about +6db compared to 100Hz. Again, you can see the 100-200Hz range still needs some improvement.
edit: just want to point out my target curve was based on FR graph and listening/tweaking.
 

For comparison:
Blue - subs in rear corners
Purple - subs centered F&R
Green subs centered F&R with EQ


Relocating the subs seems to have compensated for the mains dropping off so steeply around the crossover point (80Hz in this case). I also found that putting 4"-6" thickness of damping material directly behind the mains and on the side walls directly adjacent to the mains seemed to even things out a bit above the crossover point, but that area still needs some work. Another huge benefit of this placement is that the bass is very consistent between the front and back rows now. Previously there was a huge variation.

I think the next step is indeed to get some substantial damping on the front wall, and possibly still do some corner traps. Making progress though.


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## bpape

Looking good. 5db range from 20 to over 100 is great.

BTW, that's one of the suggested positioning strategies identified in the Harman white paper. The other is the center of the 2 side walls.


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## Peter Loeser

bpape said:


> Looking good. 5db range from 20 to over 100 is great.
> 
> BTW, that's one of the suggested positioning strategies identified in the Harman white paper. The other is the center of the 2 side walls.


Yep, that's where I had originally heard of it. Initially I hadn't planned to try it for a few reasons. First, I had tried the centers of the side walls and it didn't work any better than the rear corner placement. Second, the dual Chane subs are powered by a single Dayton SA1000 which makes for a long exposed wire run. Last, I had to slide the rear seat up a few inches to fit one behind it. Having tried most everything else I figured I'd at least give it a shot. I'm glad I did. Supposedly one sub centered on each of the four walls is a good option too.


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## bpape

As is 1 in each of the 4 corners - but you found the one that works best for you which is good.


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## Peter Loeser

Ok, moving on to the next step with the assumption that I'll settle on a dual sub setup for good response below 100Hz and maybe add corner traps in the back later. Now looking at the response of the mains from 80Hz to 400Hz. It appears I need treatment on the front wall now since moving the mains side-to-side or out into the room isn't practical and didn't provide a measurable improvement. So I'm looking at GIK 242 panels compared to 244 panels, for the front. The test graphs look to be given with different units, so I'm not sure what the difference is between the two in the range I'm concerned about. Do I...

1. move some or all of my existing 244 panels to the front wall and get some 242 panels for the side walls? (easy on budget)

2. leave 244 panels on side walls and add 242 panels to the front wall? (easy on budget)

3. leave 244 panels on side walls and add 244 panels to the front wall? (stretching budget)

4. something totally different?

Couple details - I can't do corner traps in the front vertical corners, and I don't want to go too thick with treatments on the front walls since I currently have a curtain hung for aesthetics. 244 panel thickness might be pushing it there.


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## bpape

242's won't get down to 80 and doubt that the problems down there are front wall anyway. If you can move the speakers closer or farther from the wall to see what issues are coming from that, we can give a better recommendation on what would work. Could also be the ceiling if a peak or cancellation off the wall behind you if a null.


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## Peter Loeser

Thanks as always for the quick and helpful response last week Bryan. I had a chance tonight to do some more measuring. I have moved my Paradigms back into place as my review of the Chane speakers is finished (although I still temporarily have the subs hooked up and one PEQ filter to tame a peak around 70Hz). I played around a bit with the placement of the front right speaker and did some full range sweeps of the right channel plus subs. Turns out moving the front speaker out into the room (while maintaining same distance from the side wall) makes a drastic difference in the response between 100Hz and 400Hz - i.e. my problem area. So I guess this is good news in the sense that it should help narrow down the issue, but not great news in the sense that it's not practical to leave the front speakers in the position that gave the best response.

Here are the measurements. Distances are from front wall to roughly front panel of the speaker. In all cases the speaker is 1/4 of the room width from the side wall.

24" from front wall (most convenient location, worst response)
 

31" from front wall (not great placement, better response)
 

42" from front wall (worst location, best response :rolleyesno
 

Combined (including 47.5" from wall which was no better than 42")
 

Waterfall for the 42" location
 

Does this confirm that the front wall needs to be treated with something pretty thick? I would like to achieve the response of the third graph at the speaker location of the first graph, if possible.


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## NBPk402

Question: When you are measuring from the back wall... Is it to the front of the speaker or the rear? My speakers are currently 2' from the rear of the speaker but will be within inches when i move the screen back. If I measure from the front of the speaker I am 6' from the wall, and later will be 4' from the back wall.


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## Peter Loeser

ellisr63 said:


> Question: When you are measuring from the back wall... Is it to the front of the speaker or the rear? My speakers are currently 2' from the rear of the speaker but will be within inches when i move the screen back. If I measure from the front of the speaker I am 6' from the wall, and later will be 4' from the back wall.


Ron - all of my measurements are from the front wall to the front of the speaker, so as you said the gap between the front wall and back of my speaker would be smaller by 18" or so. Unfortunately my room arrangement makes it extremely impractical to put them 3'-4' out into the room where the response is clearly much better.

The actual distances in this case are mostly arbitrary, and the purpose of the experiment was to determine if the speaker's proximity to the front wall was affecting it's response from 100Hz-400Hz. Once I've added appropriate treatments I'll still tweak the final position of the speakers to balance good response and aesthetics/convenience.

edit: my goal here is not only to have good response from my mains and subs, but to also end up with a room that is much less sensitive to placement of mains and subs.


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## NBPk402

Peter Loeser said:


> Ron - all of my measurements are from the front wall to the front of the speaker, so as you said the gap between the front wall and back of my speaker would be smaller by 18" or so. Unfortunately my room arrangement makes it extremely impractical to put them 3'-4' out into the room where the response is clearly much better.
> 
> The actual distances in this case are mostly arbitrary, and the purpose of the experiment was to determine if the speaker's proximity to the front wall was affecting it's response from 100Hz-400Hz. Once I've added appropriate treatments I'll still tweak the final position of the speakers to balance good response and aesthetics/convenience.
> 
> edit: my goal here is not only to have good response from my mains and subs, but to also end up with a room that is much less sensitive to placement of mains and subs.


Thanks for the info Peter... I am assuming your speakers are maybe a foot or so deep? What would happen if you made a acoustic baffle wall sealing off the speakers from the rear wall, but at the same time you would have a cavity for the return waves to be absorbed? You could then wrap the baffle wall with GOM (if you don't have a AT screen)... I am thinking that it might work nicely as a bass trap too. :T


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## Peter Loeser

ellisr63 said:


> Thanks for the info Peter... I am assuming your speakers are maybe a foot or so deep? What would happen if you made a acoustic baffle wall sealing off the speakers from the rear wall, but at the same time you would have a cavity for the return waves to be absorbed? You could then wrap the baffle wall with GOM (if you don't have a AT screen)... I am thinking that it might work nicely as a bass trap too. :T


They are 17"-18" deep. The baffle wall could potentially help. I'm not using a projector and my front wall has doors on either side, just outside my mains. Since the TV and door locations plus room layout don't give me a lot of freedom to move the speakers around, I'm hoping I can do something with the room itself to cut back on its effects on the mains' response. If I had the front corners free (no doors) I'd stack some corner traps there. In hindsight flipping the room 180º might have been a better option, but I'd have had to hang the TV over a window and run a lot more wiring to the opposite side of the room. I might still do that someday.

Here is a current pic of my front wall to give you an idea.
 

Door locations for reference. Mains are hard to see but are positioned between display and doors.


I would eventually like to do a PJ and AT screen with mains and CC behind. I could fit about 120"-130" (don't remember what I calculated) diagonal screen in the space between the doors. I would bump the whole curtain/false wall out into the room deep enough to fit the mains and CC behind the screen and front sub behind the curtain below the screen. I could then very easily acoustically treat that whole front wall and maybe even do some kind of baffle as you suggested.


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## Peter Loeser

Bryan - any suggestions based on the latest set of graphs comparing the mains close to the wall vs out in the room?


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## bpape

42" is most definitely the best response and not at all too far forward from a performance and depth of imaging standpoint. Why is this not practical? 

Try moving them back to the moderate position and playing with the distance to the side wall and see if you can balance it out between the 2.


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## Peter Loeser

bpape said:


> 42" is most definitely the best response and not at all too far forward from a performance and depth of imaging standpoint. Why is this not practical? Try moving them back to the moderate position and playing with the distance to the side wall and see if you can balance it out between the 2.


The 42" position puts the left speaker directly in the path of anyone coming into or out of the room. It wouldn't be catastrophic, just not convenient. I guess I could stick them there for a couple weeks and see if I can tolerate it.


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## phazewolf

So how is it going with the speaker placement issue's you have been dealing with? Have you thought about going 30" from the wall and placing a monster trap behind them? Maybe try a 242 and a 244 behind each main andifference see how it sounds.

Just a thought.


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## phillihp23

Now you got me thinking about tweaking my speaker placement Peter :nono:
I have restricted speaker place options also. My front wall is 10' from my seat. If I moved the speaker further into the room, away from the front wall, I worry when I recline the speaker may become a footrest.
:yikes:


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## Peter Loeser

phazewolf said:


> So how is it going with the speaker placement issue's you have been dealing with? Have you thought about going 30" from the wall and placing a monster trap behind them? Maybe try a 242 and a 244 behind each main andifference see how it sounds. Just a thought.


Since my last post here I have made a couple changes. The Chane subs are gone so I'm running my Studio 100s full range until my new subs arrive in a few days. I also have a Yamaha RX-A3040 in the system for review. My mains are currently spaced out 33 inches (front of speaker to front wall). I have not done any REW sweeps of this setup but for music it is sounding as good as I've ever heard it sound. I don't know if it's a matter of finding a sweet spot for the speakers or if the Yamaha is just a much better match for them. I mean, I'm _really_ pleased with the sound as it is right now. I am still planning to put some panels behind the mains and possibly some corner traps in the back of the room. I'd still like to get the room to a point where acoustics are less affected by speaker placement. I have six 2" thick OC panels that I will probably use to make some panels for the front wall. 




phillihp23 said:


> Now you got me thinking about tweaking my speaker placement Peter :nono: I have restricted speaker place options also. My front wall is 10' from my seat. If I moved the speaker further into the room, away from the front wall, I worry when I recline the speaker may become a footrest. :yikes:


Your situation is somewhat similar to mine, but it sounds like I have a bit more room up front. I can live with the mains out into the room a bit, it's just a matter of having to walk around one when coming into the room. If it sounds this good though that is a small price to pay. If I can get good results with panels on the front wall and move the mains back a bit, I'll be a happy camper. I'm going to leave things as they are until my subs are set up. I'll play with crossover settings to see what I come up with and go from there.


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## NBPk402

Peter Loeser said:


> Since my last post here I have made a couple changes. The Chane subs are gone so I'm running my Studio 100s full range until my new subs arrive in a few days. I also have a Yamaha RX-A3040 in the system for review. My mains are currently spaced out 33 inches (front of speaker to front wall). I have not done any REW sweeps of this setup but for music it is sounding as good as I've ever heard it sound. I don't know if it's a matter of finding a sweet spot for the speakers or if the Yamaha is just a much better match for them. I mean, I'm _really_ pleased with the sound as it is right now. I am still planning to put some panels behind the mains and possibly some corner traps in the back of the room. I'd still like to get the room to a point where acoustics are less affected by speaker placement. I have six 2" thick OC panels that I will probably use to make some panels for the front wall.
> 
> 
> Your situation is somewhat similar to mine, but it sounds like I have a bit more room up front. I can live with the mains out into the room a bit, it's just a matter of having to walk around one when coming into the room. If it sounds this good though that is a small price to pay. If I can get good results with panels on the front wall and move the mains back a bit, I'll be a happy camper. I'm going to leave things as they are until my subs are set up. I'll play with crossover settings to see what I come up with and go from there.


Would treating the wall behind the speakers alleviate having to bring the speakers out into the room?


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## Peter Loeser

ellisr63 said:


> Would treating the wall behind the speakers alleviate having to bring the speakers out into the room?


Potentially yes. In my case I think reflections off the front wall are causing some cancellation in the 100Hz-400Hz range at the MLP. Some bass trapping on the front wall should improve that in theory.


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## Dwight Angus

I treated my front wall without moving speakers out in the room & noticed big improvement in the low to mid range frequencies


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## Peter Loeser

Good to know. I think I will end up treating most of the front wall with 2" thick panels, and use 4" thickness behind the speakers and see if that improves the mid-bass response enough to move the mains a bit closer to the wall.


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## Dwight Angus

I treated the entire front wall with 2 inch linacoustic 1st & then installed corner front bass traps. Big improvement. I have a false wall with acoustic screen so the installation is behind acoustic screen.


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## Dwight Angus

My back of the mains are 12 inch from back wall.


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## Peter Loeser

My current display is a 60" plasma, so I could do a partial false wall, which Ron suggested earlier in this thread. I have some ideas for that option which I may explore down the road. It would allow me to easily treat the whole front wall and bring the TV out into alignment with the front of the speakers. Eventually I would like to go to a projector setup, but probably not until 4k prices come way down. I will probably order some DIY frames soon for the OC boards I have left, and at least mount a panel behind each speaker and see where that gets me.


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## NBPk402

I am looking at treating the whole wall behind the screen with either 1 layer of 3" Roxul R60 or 1 layer of 9" Fiberglass insulation (fluffy). :T


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## Peter Loeser

How would you attach the R60 if you go that route?


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## phazewolf

You would take the fluffy and put it in sacks think of large pillows but filled with pink fiberglass.


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## NBPk402

Peter Loeser said:


> How would you attach the R60 if you go that route?


I am thinking of making a 2"x4" frame for the single R60, going from one wall to the other, and floor to ceiling, and then boxing the outer frame to 2'x4' sections. Once that is done I would stuff the chambers with the R60, and then staple Black Commando Cloth over the whole wall.

If I do the 9" fluffy... I would space out a false wall from the wall, staple the fluffy to the frame, cover this with thin rubber (to avoid to much high frequency absorption), and then staple the Black Commando Cloth to cover the insulation.


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## Peter Loeser

I have some ideas for changing up the front of the room a bit, most likely moving the curtain wall (and TV) out into the a bit to match up with the mains which I pulled away from the wall a bit. Something along the lines of what Ron has suggested above.

In the meantime, I still have some nulls that I'm hoping to correct with treatments. I ordered a set of Tri-Traps for the rear corners and some hooks to convert my original wall panels to ceiling panels.


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## NBPk402

Peter Loeser said:


> I have some ideas for changing up the front of the room a bit, most likely moving the curtain wall (and TV) out into the a bit to match up with the mains which I pulled away from the wall a bit. Something along the lines of what Ron has suggested above.
> 
> In the meantime, I still have some nulls that I'm hoping to correct with treatments. I ordered a set of Tri-Traps for the rear corners and some hooks to convert my original wall panels to ceiling panels.


What we ended up doing was... Framing out the wall with 2x4's, and then stuffing R60 into the cavities. We then covered the whole wall with black commando cloth. :T


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## Peter Loeser

My GIK Tri Traps came today and I finished mounting some 2" thick panels at the first reflection points overhead. Too late to listen/measure by the time I was done but hopefully I'll have a chance later this week. The Tri Traps are temporarily propped up on tables I already had in the corners. Once I find the best spots I'll do something more permanent. I think I have enough height to stack two in each corner, so I'm keeping that option open as well.

The ceiling panels are the ones that used to be on the side walls. They're hacked together and don't have good straight edges, so they look a little funny for now. My plan is to get some frames to put them in so they look nice and square. Bryan, if you're still here - can I order the cloth GIK uses for their panels? I'd like to wrap my DIY panels to match the ones from GIK.


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## Peter Loeser

Photos


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## bpape

Sure - I can work that out for you. Drop me an email.


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## Peter Loeser

Update and pics. I was still getting a lot of slap echo in the back of the room and felt bass response could still be improved, so I ordered a second set of Tri-Traps and another pair of 244 panels. Traps are stacked two in each corner and each side wall has four 244 panels. Haven't taken measurements yet, but will be doing it soon for my Anthem MRX-710 setup and review. I will take treatments out to get a "before" measurement too. I have new frames for the ceiling panels, I just need to assemble them with the other spare 705 panels and get some of the GIK fabric to wrap them. Stay tuned for some graphs.


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## Jedi940

Just read through your thread. Some excellent stuff here. Looking forward to your upcoming measurements.


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## Peter Loeser

Jedi940 said:


> Just read through your thread. Some excellent stuff here. Looking forward to your upcoming measurements.


Thanks, it has definitely been a learning process. If I have the opportunity to build another HT in the future, I'll start with proper room treatments rather than the flimsy DIY panels I originally made.


Here's a question for the experts. I'm planning to add a slanted section to the left wall (when facing the TV) to match the slant on the right and back walls. I don't plan to demo the existing wall since it's all blown insulation above and I don't want the mess. As a result, I'll end up with a cavity between the existing wall and the new slanted section. Should I expect that to cause any acoustic problems if I just leave it hollow i.e. unwanted resonance, etc? Is it worth trying to fill with some kind of insulation? Would that act as a bass trap or just be a waste of time/money?

If you look in the picture above the black curtain you can see the angled section to the right, but not the left. I'm just planning to make it symmetrical from left to right.


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