# Using RTA to position subs/mains



## jdeanmc (Aug 26, 2008)

Hey Guys,
If this isnt in the right area please let me know...
I have decided to start over with my setup.
Step one,i want to make sure ive got sub(s)in the best location for my room to get the best response.
Is using Rta in Rew my best bet for this?Put sub in lp and move the mic around to find smoothest response?then swap positions?
i have the HSU vtf mk3 ho and the MBM12.how do you do this with 2 subs?
Can i also us the Rta to get the mains in the best position.Toe in,distance apart,distance from wall etc...for the best soundstage?
Can someone please clue me in on the rta setup.ive looked through online help files,but dont see what i need,i did see a post from Brucek from 3/7/2009 on the subject(.RTA 1/24 octave.pink pn.fft 65536.average=2.window=rectangular.no bars.y axis=dbfs with scale -70 to 0)
Any thoughts?im i going about all this correctly?
Dean


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## brucek (Apr 11, 2006)

> Is using Rta in Rew my best bet for this?Put sub in lp and move the mic around to find smoothest response?then swap positions?


Yep.



> have the HSU vtf mk3 ho and the MBM12.how do you do this with 2 subs?


A lot of trial and error if you aren't planning on co-locating them.



> Can i also us the Rta to get the mains in the best position.Toe in,distance apart,distance from wall etc...for the best soundstage?


You can give it a shot, but again the problem with two mains will make it difficult. The RTA is certainly useful at the listening position to adjust the subs phase control when you have the sub and mains playing to obtain the smoothest crossover region.



> Can someone please clue me in on the rta setup.ive looked through online help files


Follow the info below on using the RTA:

_To use the RTA feature of REW, you must first setup the levels as if you were about to make a standard response measurement. 

This involves running the Check Levels routine for the mic at the listening position to 75dB and the Calibrate routine. You can even run a measure to have a reference.

Then, select the Spectrum tab in REW and setup the controls as shown in the picture below.

Then, select the REW Generator and select Pink PN and start the signal using the play button.

Press the Red record button on the Spectrum page.

You can monitor your Input Level on the Spectrum page in the bottom left hand corner. 

If it reads clip at any time (because you're moving the mic around when using the RTA), then simply turn down the REW input level a bit.

Below shows a response measure I took (that gets transferred to the RTA graph), and the black line is the RTA itself. Now I'm ready to move the mic around and watch the black line change._










brucek


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## Wayne A. Pflughaupt (Apr 13, 2006)

> i have the HSU vtf mk3 ho and the MBM12.how do you do this with 2 subs?


No different, since the two function to cover the entire low end: put them both at the listening position for testing, then put them both in the location with best response.



> Can i also us the Rta to get the mains in the best position.Toe in,distance apart,distance from wall etc...for the best soundstage?


Not sure there's a definitive answer for this - others may want to chime in with their thoughts. My thinking is that REW won't do anything to help determine the best soundstage, since it's a mono signal. That's something you'll just have to do by ear.

As far as determining the best position from walls, etc. REW can help there. Smooth your RTA reading to 1/3 octave (hopefully you can do that with the RTA? I've never used it full range) and look for the larger peaks or dips in response below 500 Hz or so (which is about the frequency that the room really starts to influence things). See if re-positioning can minimizing the peaks and dips, but not at the expense of placement for the best soundstage.

Regards,
Wayne


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## weverb (Aug 15, 2008)

Hey Dean,

We have not heard from you in awhile. Maybe post a full range graph of your current set-up and list some of things you are not happy with. Wayne and brucek are great at reading the graphs and making suggestions for improvement. Another option you may want to start researching is sound treatment panels. I have noticed an actual improvement in my current set-up with just a few diy panels.


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## jdeanmc (Aug 26, 2008)

I will try to get graphs up.
Its not that my setup doesnt sound good,it does.I just want more than good!!!
I still feel like im lacking that "room filling"low end,ive got descent bass,but no "pressure"
I can cut the HO off and there is really no audible difference whether its off or on.seems like the mbm does all the heavy lifting.
I did (for some reason)gut my mains and noticed that 2 screws on each woofer was pulled through.The woofers werent "sealed"to the cabinet.i fixed this and do notice a great deal of improvement in "clarity"now i want to start over and make sure im getting all i can from subs,location,setup etc...
I do have panels in the first reflection points and a few on the back wall.
I had considered adding another Ho but after speaking with Pete at HSU,he stated i should have plenty of sub for my size room?
I will try to get graphs up in a day or two.
Thanks for all the help.
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> I still feel like im lacking that "room filling"low end,ive got descent bass,but no "pressure"
> I can cut the HO off and there is really no audible difference whether its off or on.seems like the mbm does all the heavy lifting.


Hey Dean,

Can you post a layout and give us more details on your room. "Pressure" is going to be very difficult unless you have a "sealed" room. Mine opens to other areas of the house. No matter how many drivers I add, I will never pressurize my space. :sad2:


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## jdeanmc (Aug 26, 2008)

This would be the latest room layout i have on my computer however,things have changed.The Ho is now on the right wall almost below the first reflection panel.I have also moved and added panels.I now have 2 on each side wall.
The room is a basement room that does close off from upstairs.
Maybe trying to "pressurize"my room was a bad choice of words.I actually just feel the low end is still a little weak.maybe i need a "steeper" house curve?
I do feel like a problem is the "blend"between the mains and the subs.Ie.i set up the subs with rew and get "wall rattling"low end then after i add mains and actually watch a movie there is no "wall rattling"low end.same for music,i can crank the sub level(in the avr) from 0 db to 6.0 db and dont notice much difference.
Its like when i watch a movie or listen to music at normal level,the low-end disappears.like the mains overpower the subs??
This is what im trying to improve on.
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> Its like when i watch a movie or listen to music at normal level,the low-end disappears.like the mains overpower the subs??
> This is what im trying to improve on.
> Dean


Gotcha. We will have to wait and see your graphs. I am sure Wayne and brucek will be a big help then. I would just read Wayne's house curve post again and try his suggestion of playing something like 30Hz. and comparing it to something near your crossover point (like 90 or 100Hz.) and see if they "sound" like the same volume. That should help with your house curve.


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## jdeanmc (Aug 26, 2008)

o.k here is the mess im dealing with..
i set the subs only,check levels ,set target levels,have filters at ...
21 hz gain -16 bw 14
30.85 hz gain -6 bw 8
52.16 hz gain -12 bw 11
looked pretty good i thought.i have to set the avr volume to -18.5 to get to the proper level(at -18.5 with the mains added will run you outta the room,if not the house!!!)
then when i add the mains,set target level,check levels,i have to set the avr volume to -32
next is with the sub level maxed out
what am i missing?
makes since that when i set sub levels properly,then add mains and have to drop avr level so much here lies my problem.
i have got much better results than this before but the problem is the same.mains overpower the subs.
HELP.......
Dean


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## robbo266317 (Sep 22, 2008)

the dip between 80 Hz & 90 Hz doesn't look right. It's not evident in the sub only graph?
Have you tried inverting the phase of the subs?


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## brucek (Apr 11, 2006)

> the problem is the same.mains overpower the subs.


Why not simply reduce the level of the mains?

brucek


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## weverb (Aug 15, 2008)

Another question for you Dean. When you play your receiver's test tones, what reading do you get for your subs versus the mains? I would assume 75dB for the mains. Also, did you play just the MBM and set it to 75dB and then just the HO (and set it to 75dB)?

I would look at your phase setting on the MBM and the play with your crossover some. Try moving the MBM to one side of the couch versus behind it. Let's see if we can fix that dip. Also, what xo setting do you have on the HO? Your blend of the could be better.

What about trying both subs behind the couch? I have seen people have good results with them both back there.


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## jdeanmc (Aug 26, 2008)

robbo266317 said:


> the dip between 80 Hz & 90 Hz doesn't look right. It's not evident in the sub only graph?
> Have you tried inverting the phase of the subs?


I have switched the phase setting on both subs as well as played with the distance setting in the avr.this seems to be as good as it gets.
The thing is i can measure four or five times and this dip will only show maybe once or twice?the other times its gone?
Dean


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## jdeanmc (Aug 26, 2008)

brucek said:


> Why not simply reduce the level of the mains?
> 
> brucek


This brings a whole new level of confusion to me(yes,something this simple):unbelievable:
i run ypao.yamaha's auto calibration.to set the levels,it matches the speakers levels with each other spot on,but i dont know what level it sets them to 75db?to keep it from messing with the sub levels(as per my avr salesperson)i first set the fronts to large,lfe to fronts,i guess telling the avr i have no subs,then run ypao to do its thing,auto eq,levels etc.then turn on subs,set fronts to small set lfe to swfr.
I know i make things too complicated!!!!.point is if i lower the level of the mains,i will then have to manually set the levels of all other speakers(6.1 system)
if i do this .should i first get the subs set with a 75db target level,then without touching the avr volume,set all other speakers levels with the avr test tones(assuing thats 75 db)and at what point(what freq)are the subs at 75 db target level(10 db house curve)????
Dean


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## jdeanmc (Aug 26, 2008)

weverb said:


> Another question for you Dean. When you play your receiver's test tones, what reading do you get for your subs versus the mains? I would assume 75dB for the mains. Also, did you play just the MBM and set it to 75dB and then just the HO (and set it to 75dB)?
> 
> I would look at your phase setting on the MBM and the play with your crossover some. Try moving the MBM to one side of the couch versus behind it. Let's see if we can fix that dip. Also, what xo setting do you have on the HO? Your blend of the could be better.
> 
> What about trying both subs behind the couch? I have seen people have good results with them both back there.


I did just move the Ho from behind the couch and back to the current location.i felt that i had to have the level so low with it back there that maybe that was part of my problem?
i did measure both subs together,if i have a 10 db house curve should the level of the ho be higher than the mbm?if i ran the avr test tones to get 75 db on the mains should i be getting about 85 db on the subs?then doesnt the rat shack spl meter correction comes into play?
Sorry for making all this waaaay tooo complicated but im ready to jump into this with both feet and obsess till i put this to bed!!
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> I know i make things too complicated!!!!.point is if i lower the level of the mains,i will then have to manually set the levels of all other speakers(6.1 system)
> if i do this .should i first get the subs set with a 75db target level,then without touching the avr volume,set all other speakers levels with the avr test tones(assuing thats 75 db)and at what point(what freq)are the subs at 75 db target level(10 db house curve)????
> Dean


I would manually set the mains level to 75dB (set as "small")using the receivers test tones. Then do the same for the surround speakers. Once those sound level, I would turn the HO off and run the sub test tone and set the MBM to 75dB. After that, turn the MBM off and set the HO xo to bypass and set it to 75dB using the receiver's test tone. When you have these two set, turn the MBM back on, the HO xo on and check the level for the two together.


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## weverb (Aug 15, 2008)

jdeanmc said:


> I did just move the Ho from behind the couch and back to the current location.i felt that i had to have the level so low with it back there that maybe that was part of my problem?
> i did measure both subs together,if i have a 10 db house curve should the level of the ho be higher than the mbm?if i ran the avr test tones to get 75 db on the mains should i be getting about 85 db on the subs?then doesnt the rat shack spl meter correction comes into play?
> Sorry for making all this waaaay tooo complicated but im ready to jump into this with both feet and obsess till i put this to bed!!
> Dean


Let's just start simple and don't over think things. You need to start off with things balanced first. Are you able to test things now or are you at work?


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## jdeanmc (Aug 26, 2008)

weverb said:


> Let's just start simple and don't over think things. You need to start off with things balanced first. Are you able to test things now or are you at work?


I am at work,
I have a huge bump from 20-35 hz,that i now have eq'ed down with the bfd,should i bypass all my subs filters before i do this and set the subs at 75 with an uneq'ed measurement?
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> I am at work,
> I have a huge bump from 20-35 hz,that i now have eq'ed down with the bfd,should i bypass all my subs filters before i do this and set the subs at 75 with an uneq'ed measurement?
> Dean


Yes. Then you will redo the filters. After the new filters are applied, you may have to adjust the levels to get the subs back up to the 75dB reference level. Don't worry about the house curve yet. Once you get things balanced and hear it, then you can look into adding a house curve.


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## jdeanmc (Aug 26, 2008)

weverb said:


> Yes. Then you will redo the filters. After the new filters are applied, you may have to adjust the levels to get the subs back up to the 75dB reference level. Don't worry about the house curve yet. Once you get things balanced and hear it, then you can look into adding a house curve.


Im liking this"lets start from the beginning thing"why haven't i thought of that! 

I will try to do this tonight,however it may be a day or two.now that summer has started,it seems to be difficult to get the house quite enough to measure anything!!

So ill bypass filters,bypass the house curve,cut off subs,run receiver test tones to set all speakers levels to 75,then the ho,then the mbm,then both subs(i got the procedure on that down)get everything flat to 75 db and balanced.then run rew,get filters for subs so that they are as flat as possible,get their level back to 75 db after filters.then look at house curve.am i on the right track here??
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> am i on the right track here??


Sounds like it. I would still try other sub locations if you can. If you truly feel these are the best spots then don't worry about. Just use it as an excuse to purchase more subs to smooth things out! :bigsmile:

Also, you may want to make multiple readings so we can see what you described about the dip. :nerd:


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## jdeanmc (Aug 26, 2008)

weverb said:


> Sounds like it. I would still try other sub locations if you can. If you truly feel these are the best spots then don't worry about. Just use it as an excuse to purchase more subs to smooth things out! :bigsmile:
> 
> Also, you may want to make multiple readings so we can see what you described about the dip. :nerd:


I will do this
Ill get all this going as soon as i can
BTW,i noticed a while back you sold some subs and mbm'sif you dont mind me asking, what are running now?
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> I will do this
> Ill get all this going as soon as i can
> BTW,i noticed a while back you sold some subs and mbm'sif you dont mind me asking, what are running now?
> Dean


I am running two Fi IB318's in an infinite baffle set-up. :bigsmile:


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## jdeanmc (Aug 26, 2008)

i havent had a chance yet,to check my levels or take any measurements,however the last two nights i was able to go downstairs and watch some tv/listen to some music.
I turned off the BFD,cut off subs,set speakers to large and lfe to fronts.
WOW.this sounds very nice!this is what i want with the subs involved,the low end seamless with the midrange,these speakers do go low as well,not as low as the subs,but i wasnt missing much!!
I still notice that the highs seem to be weak,on music cymbal's seem like they're 10 feet behind the drums.I can turn the treble control from 0 db to 6 db(max)and dont really hear any difference?maybe its an eq thing with the ypao?
Anyway,i hope tonight or over the weekend to be able to rerun ypao,manually set levels to 75 db and start over with the subs.

One question...
when i set levels on the mains and surrounds,i want to make a mental note of the avr volume.then set subs at this same avr volume(in an attempt to get the subs/ mains to blend fairly well before i start playing with phase and filters etc...)then i want to use sub level(in avr)and gain on subs to get as smooth of a response as i can(without touching avr volume)then when i get response as smooth as i can without any eq filters,or house curve,ill post a graph.
Im thinking out loud,but when i get to the point of "level too low"do i use the sub out to raise level?(as i dont want to move the avr volume)???
Thanks Dean


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## brucek (Apr 11, 2006)

The AVR volume is set during the Check Levels routine, so that the SPL level at the listening position is 75dBSPL. Then it isn't touched.

The REW input volume is now set to a level on REW's VU meters to be about -12dB.

Then the Calibrate routine is run and the REW internal SPL meter adjusted to 75dBSPL.

If you do that the level won't be low.

brucek


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## jdeanmc (Aug 26, 2008)

Thanks Bruce,
something simple here is what i think ive been missing,as im always turning the volume up and down!!!
As its much easier for me to adjust the subs volume over the mains,should i first cut off subs and choose to use mains in the check level routine to establish the avr volume?then turn on subs and get them up to that level using the sub gain and sub level in avr?
Dean


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## brucek (Apr 11, 2006)

Depends on what range you're measuring. 

If you're measuring the sub only, or the sub plus mains, or the mains only up to 200Hz, then use the subwoofer test signal in REW. The only time the mains test signal is used is when you are measuring full range.

To set the levels of the mains and subs before testing, use your receiver test tones.

brucek


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## jdeanmc (Aug 26, 2008)

I havent been doing this,ive done everything from REW,maybe that will make my difference.
One more bonehead question,when i click "set target level"under target setting tab,where does it "see"the level?at what freq?it seems after i hit this button,sometimes i can look at the graph and it will be at 80 hz ,sometimes its the max spl(20-25hz)in other words if it says target level for this channel is 78.4 db,what exactly is 78.4 db?an average,a particular freq?a maximum spl?
Dean


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## brucek (Apr 11, 2006)

> when i click "set target level"under target setting tab,where does it "see"the level?at what freq?


You can manually set the target level with the thumbwheels provided or you can run the Set Target Level routine that sets it automatically. 

The target level routine positions the measurement trace with respect to the target line to create optimum filters (after a band limited pink noise is generated at the sweep level).

If you're creating filters and you don't like the trace position with respect to the target line that the auto method produced, you can adjust it manually.

brucek


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## jdeanmc (Aug 26, 2008)

Thanks Bruce,
this is starting to sink in ( i think)
My problem thus far,getting the subs and mains to blend,is that ive been constantly changing the mains volume while trying to eq subs!!!
All your recent comments and guidance have sort of cleared this up.
I think you've answered all my questions
Now i need to find the time to put all this in practice and see where i go from here.
Thanks Again for your patience and expertise.
Dean


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## weverb (Aug 15, 2008)

Dean,

Looks like brucek has got you going. I would not worry about REW until you can get your mains and surrounds balanced at 75dB at the listening position using the receiver's test tones. Remember to then add the MBM first and finally the Ho. Also make sure of your procedure of turning the MBM off and the Ho xo to bypass when you start adding the main sub. Try to keep your receiver's sub setting to 0dB and use the knobs on the subs mostly. You should only be "touching" the receiver at this point to start and stop the test tones. After you have everything "playing" at 75dB at the listening position, then start measuring with REW. I am sure you are going to find that you will have to raise the Ho knob a little more after applying your filters. Don't get too hung up on the 75dB mark though. Make sure to also listen to some reference material. Case in point, my subs only reach 74dB (versus 75dB for the mains) when I play my test tones and show to be 8-10dB higher than the mains when I graph them in REW. :huh: Go figure. It sounds good to me and that's what is most important. Not the look of the graph.

Good Luck!


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## jdeanmc (Aug 26, 2008)

maybe thats due to the calibration file when using rew and nothing when doing test tones/meter?
Anyway YES,between you and Bruce,i think i have a pretty good handle on what i need to do.I thought i did before but i havent run test tones before rew,so basically i was trying to look at the graph and trying to get everything to proper levels?i dont have enough experience with that obviously.
I cant wait to give this a go and see what kind of gains i get.
Thanks for all your input
No thanks thought for getting me spending hours looking through the "build your own ib thread"i am intrigued though!!!Maybe at a later date.
Thanks again
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> No thanks thought for getting me spending hours looking through the "build your own ib thread"i am intrigued though!!!Maybe at a later date.


:bigsmile: I have already thought about your room and how an IB would do. :demon:


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## jdeanmc (Aug 26, 2008)

As i said i am intrigued with this.
At some point this may be a possibility.My Ht room backs up to a basement garage,so i could do something on the back wall,however,with my luck,the back wall would surely be the worst place for the sub.I dont really have options otherwise.
I'll make do for now and try to get the best out of what ive got,if i can get this thing sounded well enough to suite me, the next step is a projector.maybe then i can entertain the idea of cutting an Ib into a wall. 
Thanks
Dean


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## jdeanmc (Aug 26, 2008)

Hey guys,
i finally got a chance to rerun REW.
i first ran test tones to get everyhthing to 75 db
Graphs are...
1.1st measurement
2.then moved subs around to get as smooth as i could(this seems to be as good as it gets)
3.subs only.1 filter 21hz gain -8 bw 15
4.subs only 2 filters 21hz and 61.2 hz gain -1 bw 12
5.subs and mains
6.subs and mains phase set to reverse in avr
7. full range smoothed 1/3
i did cut the 61.2 hz filter after adding the mains and the "hump" reappeared so i cut it back on.it does seem to help.
after i ran test tones, to get to 75db,my avr volume was at -6.5.
i never touched it again.my rew settings were as follows...
wave volume -.398
output volume 0.200
input volume 1.000
sweep level -12
these seem strange,i had to turn the thumbwheel down to get to 75 db,i did calibrate the meter.
I havent played much source material(i ran straight upstairs to post this)but i will say what i did play so far sounds better than i've ever gotten yet.the subs do seem to have some life to them and they sound like the do blend with the mains better than they ever have.
how does all this look?
Dean


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## weverb (Aug 15, 2008)

Sorry I did not respond sooner Dean. Couple questions for you before I comment.

1. What xo setting are you using for the lfe channel? 80, 90 100Hz.?
2. What xo setting are you using for the Ho?
3. Have you tried graphing just the MBM with your current settings?
4. Have you tried graphing just the Ho with your current settings?
5. Have you tried graphing just your mains with your current settings?


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## jdeanmc (Aug 26, 2008)

Hi Weverb,
my xover is set to 80 hz.in the avr,i think i have the HO set to @ 45 hz xover "in"no turbo in mo mode
i have not graphted ho,mbm or mains alone,sounds like a good idea.
my graph looks terrible,i know.the 55 to 150 and 30 to 50 regions look way too low however me and my wife just watched taken.i have seen it before,it was her first,i can say it sounded much,much better than the first time i watched it,she commented that she thought she was about to have an anxiety attack!!!this was strictly because of the soundtrack.i have had better looking graphs but nothing has sounded close to this yet.i think its because im finally getting the mains and subs to play together(thanks brucek and you)now if i can just get everything fine tuned,maybe ill be set.come on with the suggestions
Thanks Dean


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## weverb (Aug 15, 2008)

Sorry for the delay Dean.

Your 30Hz. does not look too bad until you applied your filter at 21Hz (second graph versus third). It looks like you have more than one filter being applied there. I would double check that and try different filter settings so that you don't pull that 30Hz. area down so much. 

As for the other area, did you try different phase settings on the MBM? Have you tried it without the MBM and only the Ho? I assume the Ho is in max output mode and not max extension mode.

I was asking about the different xo settings and graphs because you can graph them alone and see where the correct xo point should be. You may be able to have a lower xo between your mains and Ho and not need the MBM. :huh: At least give it a look and listen if you have not already.


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## jdeanmc (Aug 26, 2008)

weverb said:


> Sorry for the delay Dean.
> 
> Your 30Hz. does not look too bad until you applied your filter at 21Hz (second graph versus third). It looks like you have more than one filter being applied there. I would double check that and try different filter settings so that you don't pull that 30Hz. area down so much.
> 
> ...


My 21 hz filter has a pretty wide bandwidth?also the second graphs has the target line at 75 hz third has a 80 hz target(applied house curve,i think)maybe thats why the 30 hz looks different.
So you'd like to see the ho,mbm and mains seperately?i'll try to get graphs on this.
I moved subs around slightly,but if need be i can start over and do the rta "crawl"i could also try to co-locate the subs,the only time they have been close is both next to each other behind the sofa.

Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> My 21 hz filter has a pretty wide bandwidth?also the second graphs has the target line at 75 hz third has a 80 hz target(applied house curve,i think)maybe thats why the 30 hz looks different.


You are right. :coocoo: On my part.



jdeanmc said:


> So you'd like to see the ho,mbm and mains seperately?i'll try to get graphs on this.


What we are trying to do is blend the Ho and MBM better to reduce/eliminate that dip at 30-45Hz. Same goes for that MBM to main transition. Have you tried adjusting the xo knob on the Ho to see what happens?


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## weverb (Aug 15, 2008)

Also try that last graph with a target of 72dB versus 75dB and see what it looks like. 72dB seems to split the difference of your mains better.


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## jdeanmc (Aug 26, 2008)

I have played with the Ho,s crossover,ive moved it from about 40hz to 55 hz,this seems to be as good as it gets,ive contemplated trying to get rta running and moving subs to make sure they are in the best locations,i dont think ill gain much with,phase,distance settings(ive played with these at every possible setting)
i do see your point about losing the mbm,ill give that a try.
any other suggestions before i disconnect subs and start with the moving?
Thanks for all the attention
Dean


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## jdeanmc (Aug 26, 2008)

to whom it may concern.
1st graph mains only.
red-left only.green right only.blue-both mains to 200 hz
next graph same but full range
does it not look like left and right are out of phase?


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## jdeanmc (Aug 26, 2008)

subs only
light purple-HO only 48 hx crossover
dark purple-MBM only
blue-both subs


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## jdeanmc (Aug 26, 2008)

subs and mains
first to 200 hz unsmoothed
next to 3k hz smoothed by 1/3
im not quite there yet,but ive considered...
$3-$400 each for adcom or yamaha amps(wayne,you,ve cleared me up on that)
$1200 to $1300 to upgrade to klipsch rf-7 fronts PLUS $400 to $500 for rc-7 center.
$1300 to $1600 for sub upgrade
or getting Weverb,Brucek,Wayne to fly to huntsville international airport(HSV)picking you guys up(its only 10 mins away)spending an evening getting me the best out of what i have,feeding you filet's(big green egg style)and sending you back home!!!
What would be the cost???
Please help
i have become obssessed with this!!!!
Dean


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## brucek (Apr 11, 2006)

Those plots look quite good now. Hopefully, it sounds good too.

brucek


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## weverb (Aug 15, 2008)

jdeanmc said:


> im not quite there yet,but ive considered...
> or getting Weverb,Brucek,Wayne to fly to huntsville international airport(HSV)picking you guys up(its only 10 mins away)spending an evening getting me the best out of what i have,feeding you filet's(big green egg style)and sending you back home!!!
> What would be the cost???


:bigsmile: Dean that is funny. Atlanta is only about 6 hours from home!

I have to agree with brucek. That last plot is looking good. I know you listed a bunch of possible upgrades, but I think there is one route you missed. You already started some. I think sound panels will help a lot more in your room. You have very reflective walls with all that wood paneling. You really could use a lot more treatment. I would look at diy or at ATS to help keep the cost way down.

http://www.atsacoustics.com/

I noticed a huge difference in my room with the little sound treatments I have done. brucek posted about another really cool feature in REW called Energy Time plots (ETC). It will help show you if you have addressed all your reflection points. Here is the post I am referring to:

http://www.hometheatershack.com/for...rew-analysis-voiceover-studio.html#post170156

Besides the reflection points, you have a lot of corners in that room. Bass trapping is going to help the bass a lot. You can get very creative to help make any type of treatment blend in the room.

If you are not ready or the WAF prohibits sound panels, you can start adding another MBM to help smooth things out. What's most important though is how it sounds to you. Don't get too caught up in how the graph looks. Worry more about how it sounds. I would spend some more time listening/watching some reference material and really pay attention to see if any thing is lacking or is too much. You should feel :yay2: with the headway you have made so far.


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## Synthsayer (Dec 19, 2007)

TRY THIS, IT WORKED FOR ME: If your sub amp has a continuous or variable phase control set it to about 90 degrees, and then start adjusting in slightly increasing amounts. Most likely you will wind up with a setting around 135 degrees. This combines the 90 degree phase shift of the 1st order crossover and the natural ACOUSTIC PHASE differences between mains and subwoofer of approximately 45 degrees.
I have been working with subwoofer placement and phase alignment between main speakers and subwoofer for several years. Getting my system adjusted to where it sounds like all of the sound is coming from the fronts, center, and rear speakers with the sub really being almost inaudible until some strong low end kicks in has been a big challenge. But, after a lot of research, crawling around the room, and calculations, the system sounds very good.
Sure, people say to 'put the sub in your listening position, crawl around the room on your hands and knees until your hear the sub the way you think it sounds best' and bingo put the sub woofer in that spot and you're done. HA! Don't believe it for a moment. Not to mention the fact that my sub is a 3 cubic foot cabinet weighing 90 lbs. Sure, I can put that on my couch.???
Some people will say that bass signals below 300Hz are non-directional. But with Room Modes and other acoustic anomalies it is not always true. Give strong consideration to using bass traps in corners nearest the subwoofer, along walls, and other corners. This will make an incredible difference getting your system aligned without a bunch of moving the sub all over the room until your back gives out. For excellent videos of 



 check out this YouTube Site
Now it's time to get technical and bring up some relative factors that will impact your ability to properly place and 'phase align' your sub and main speakers. 
You can see my post about considering the natural phase characteristics of the passive crossovers of the main speakers at this thread
To be brief and not overly technical the main point is this: Your powered subwoofer has no passive crossover components and likely uses a fourth order, 24db/octave Linkwitz/Riley active crossover which is 'in phase'.
Your main speakers may only have First Order 6db/octave PASSIVE Crossovers (Crossovers made with combinations of inductor coils and capacitors). This type crossover has a phase shift of 90 degrees. If you have more expensive high-end mains, then you may have 2nd, 3rd, or even 4th order PASSIVE Crossovers.
For this example I focus on 1st and second order PASSIVE crossovers since they are the most common.
Consider this: The sub amp contains the 24db Linkwitz/Riley ACTIVE crossover, phase inversion switch or continuous phase control, and maybe a parametric EQ. We consider the subwoofer's input and output to be 'in phase'. Say your main speakers have Passive first order crossovers. (The main part of the crossover we are concerned with is the Low Pass section). *The 1st order crossover is 90 degrees 'out of phase' compared with the subwoofer.*
If your subwoofer has no phase adjustment or only a phase reverse switch then you will have a tough time getting the phase problem solved and achieving the best sound reproduction. I am going to consult a friend who has done electronics design for Elan Home Systems to see if adding a small inductor in series with the subwoofer voice coil would solve the problem and post another reply.
The most important thing is to know the type of PASSIVE crossover used in your main speakers and whether they are 1st, 2nd, 3rd, or 4th order.


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## JimP (May 18, 2006)

Dean,

Are you in Huntsville Alabama or Huntsville Texas? I'm in Wetumpka AL north of Montgomery.

Back to you problem. First, I went through the whole MBM thing with a Velodyne HGS15. Talk about struggling with it. I think part of the problem that you're experiencing may be in timing differences between the MBM-12 and your deep sub. I don't honestly believe that a phase adjustment does the same thing. At one time, I added a Behringer something in other (still have it in junk room) in order to play with trying to get the same amount of delay between the two subs (includes the mbm). It helped only a little. One thing I think we're overlooking is that depending on volume, your group delay changes and keeps you from keeping the mbm and sub properly time aligned and causes cancellations. You're also dealing with different slopes and their interactions. In my configuration, I guess I didn't really need the mbm as my sub was pretty good at mid bass. I wound up ebaying the mbm and went back to using just the sub. Since then, I bought a SVS PB Ultra 13 which knowing what I know now I might not have done. (If you're interested in a HGS15, let me know.) 

If you're in Huntsville Alabama, I could drive up there to help, but if the problem is as I'm suggesting, its not really fixable with your current equipment configuration.


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## weverb (Aug 15, 2008)

Synthsayer said:


> If your sub amp has a continuous or variable phase control set it to about 90 degrees, and then start adjusting in slightly increasing amounts. Most likely you will wind up with a setting around 135 degrees.


The HSU Ho sub only has a phase setting of 0 or 180 degrees. Nothing in between.


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## jdeanmc (Aug 26, 2008)

brucek said:


> Those plots look quite good now. Hopefully, it sounds good too.
> 
> brucek


Actually it does sound better than it ever has,i am pleased.I just wanted to make sure im not missing something(freq.wise)
Thanks btw for all the help
Dean


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## jdeanmc (Aug 26, 2008)

weverb said:


> :bigsmile: Dean that is funny. Atlanta is only about 6 hours from home!
> Funny you say,i meant not to be funny!!!
> 
> Actually,i do have some OC703 left.so i could make a few more panels.
> ...


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## jdeanmc (Aug 26, 2008)

JimP said:


> Dean,
> 
> Are you in Huntsville Alabama or Huntsville Texas? I'm in Wetumpka AL north of Montgomery.
> 
> ...



i am in Decatur Alabama,10 mins from Hunstville.I did live in Montgomery for a year(several years back)and went to Wetumpka weekly with my job(worked for IBM,servicing your Wal-mart's euipment)
I may take you up on the drive up thing.
One problem i have,is that Po-dunk Decatur(though i do love it)has no Home Theater dealers,i have never even been in a Home theater(other than mine)so how the would i know when to stop!!!
I think it sounds good.but Does it?HMMmmmm!!
Thanks Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> Actually,i do have some OC703 left.so i could make a few more panels.


If you can, don't forget to have at least a 2" gap behind the reflection panels. This will help reach down into the higher mid bass region.


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## weverb (Aug 15, 2008)

jdeanmc said:


> i am in Decatur Alabama,10 mins from Hunstville.I did live in Montgomery for a year(several years back)and went to Wetumpka weekly with my job(worked for IBM,servicing your Wal-mart's euipment)
> I may take you up on the drive up thing.
> One problem i have,is that Po-dunk Decatur(though i do love it)has no Home Theater dealers,i have never even been in a Home theater(other than mine)so how the would i know when to stop!!!
> I think it sounds good.but Does it?HMMmmmm!!
> Thanks Dean


How about a "good" movie theater? How odes your room sound compared to the best theater you have been to?


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## jdeanmc (Aug 26, 2008)

weverb said:


> If you can, don't forget to have at least a 2" gap behind the reflection panels. This will help reach down into the higher mid bass region.


Gotcha.My first panels i built,i did this .i built a frame out of 1x2's and put the 703 on top of this.then i redid frames and built the frame around the 703.so now they have no gap.Back to the drawing board!!!
Thanks Dean


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## JimP (May 18, 2006)

dean,

You're welcome to come visit.

By the way, I tried the hard knee house curve and found that it was too much. But I do run the sub a few dbs hotter than the mains.


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## jdeanmc (Aug 26, 2008)

weverb said:


> How about a "good" movie theater? How odes your room sound compared to the best theater you have been to?


Actually,it sounds better than any theater ive been to.Does that mean my system is awesome?or that the theaters ive been to were ?

O.k. so no takers on me flying everyone in,so bruce,wayne and you should send me your addressess,ill mapquest,come over unannounced and listen to your systems,one by one(i'll then need each of you to grill ME a filet though!!!)although ill have to bring each of you a big green egg and boy,you thing subs are heavy!!!

Anyway i really have become impressed within the last week or so.Mainly i think due to Bruce and you answering post after post after post and getting my head around what i was doing wrong.Ie.running test tones first then getting subs to 'match"the levels of mains better.
Before all my graphs looked alright,every post said "looks good"but it sounded like .mains overpowered the subs so bad that if i cranked the avr volume up enough to get the subs levels where the graphs showed they were(88-80db at 25 hz)you'd have to go in the backyard because the mains would run you out of the room!!!!!!!!i thought "this can't be right!!"
Again thanks so much for all the help.
Dean


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## brucek (Apr 11, 2006)

Synthsayer said:


> If your subwoofer has no phase adjustment or only a phase reverse switch then you will have a tough time getting the phase problem solved and achieving the best sound reproduction.............
> The most important thing is to know the type of PASSIVE crossover used in your main speakers and whether they are 1st, 2nd, 3rd, or 4th order.


The receivers subwoofer distance trim is an excellent proxy for a phase control, so no problem that a sub doesn't have its own variable control.

Certainly the box enclosure has the largest effect on the speakers rolloff, where vented can be twice the rolloff of a closed box. Either way, the receivers 2nd order crossover for the mains is half that of the standard 4th order of the receivers subwoofers crossover. This 2nd order is chosen to theoretically combine with a mains natural rolloff to attempt to achieve the 4th order 24dB/octave that the subwoofer already enjoys.

Since it ain't a perfect world, and combined with the different rolloffs that different mains speakers may offer, the phase or time (distance) adjustment is there to balance the phase out between the sub and mains to obtain the smoothest response.

Enter the MBM and it throws a huge wrench into the works. I won't make a speech about what I think about the MBM theory, other than to say a single capable sub is your best bet to achieve a smooth transition over the low frequency range.

brucek


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## Synthsayer (Dec 19, 2007)

Do you know the slope of the main speaker crossover? Is it 6db, 12db per octave? What kind of main speakers do you use? The type of crossover information should be in the spec sheet from the manufacturer. The only other way to find out is to contact the manufacturer via email, ask forum members, or open one the speakers and visually examine the crossover. If it comes to that I can describe to you how to distinguish what type crossover it is.
This is the real rub with phase problems. Just like yours, many powered subs only have the 0 or 180 switch, not a variable control. Some have no control at all. 
Another problem is that without the Thiele/Small parameters for the woofers in the main speakers, and the subwoofer driver it is practically, if not totally impossible to calculate or plot phase angles using speaker system design tools like the free WinISDbeta from Linearteam or others. On top of all that, this does not include the phase characteristics of the crossover thats built into your AVR. I won't even get into that part of this. We can only assume that the AVR crossover is in phase.
Sorry, I know this sounds like an impossible situation to resolve, but there is bound to be a solution, somewhere.
Loudspeaker phase is one of the most mysterious and problematic areas of loudspeaker design. It is one reason 'Full-Range' drivers have regained popularity with home theater systems. No crossovers means no, or at least less, phase problem.Jim Thiel of Thiel Audio, (which I used to sell years ago) has been working in this area for the last 20 years. 
I know you just want to get your system adjusted to where the sub does not sound totally seperate from the mains. There are some tricks that might let you work around the phase adjustments. Look at this Web page for RhythmicAudio and how to use an AVR speaker DISTANCE setting to compensate for phase and group delay problems. Without the woofer and subwoofer phase graphs you are kind of shooting in the dark, but if you make small, 1 foot adjustments to the distance setting for the subwoofer, it may be possible to bring everything together. As the RhythmicAudio site states, the end distance setting on the AVR may be nowhere near the actual physical distance between you and the sub.
TIP: When male and female voices in dialogue or music sound full, without the sub standing out in the mix, you are very close to being in phase. When you get the right setting your sub should disappear until the real lown end content comes in. If it is out of phase you will notice that the voices seem to lose definition at certain frequencies around the frequency your AVR sub crossover or powered sub crossover is set.
Once you have it right the bass will seem to come from out of nowhere and should even surprise or startle you when it does.
If you really want to see how in-depth Thiel and other top designers, including Zigfried Linkwitz, one of the developers of the Linkwitz/Riley crossover theory, and Elliot Sound in Australia, get into this problem and the solutions, click the links to see their sites.
Also, I strongly suggest some type of bass trap. You will probably need 2 or 3 of them, but they can be made for little cost and very easily. If you want more info about that let me know, or look up DIY Bass Traps on YouTUBE. I didn't believe it until I tried it. I made 2 big corner traps for under $65. I could have done it for less. Now my friends come over and make comments like, "Where is that bass coming from?" and they are sitting 2 feet from the subwoofer.


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## weverb (Aug 15, 2008)

jdeanmc said:


> O.k. so no takers on me flying everyone in,so bruce,wayne and you should send me your addressess,ill mapquest,come over unannounced and listen to your systems,one by one(i'll then need each of you to grill ME a filet though!!!)although ill have to bring each of you a big green egg and boy,you thing subs are heavy!!!


You are always welcome to come take a listen. :bigsmile: I can smoke us some ribs/brisket/pulled pork or grill up some fillets. :meal: Just PM me for address and you can plan on taking the family to Disney too. It's just 1.5 hours away.



jdeanmc said:


> Actually,it sounds better than any theater ive been to.Does that mean my system is awesome?or that the theaters ive been to were ?


It means you are on the right track! There has to be some good stereo shops within 1-2 hours drive from you? I know there is a guy in Alabama currently building an IB ht room. :nerd:


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## Synthsayer (Dec 19, 2007)

BRAVO Brucek!!! I am in total agreement. Thank you for pointing out the rolloff characteristics. In my last post I included a link to a site that allows you to calculate distance and phase angle when using the distance control on an AVR.
For those in Alabama, check out Auburn, Alabama for audiophile and HT gear. Depending on whether you are 'Bama fans you may curse at me, but one of my oldest friends is an Auburn grad and bought some great gear there when he was in school.
( I live outside Lexington, Kentucky and am a big UK Wildcats fan, so being cursed at is nothing new. No offense intended).


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## JimP (May 18, 2006)

brucek said:


> Enter the MBM and it throws a huge wrench into the works. I won't make a speech about what I think about the MBM theory, other than to say a single capable sub is your best bet to achieve a smooth transition over the low frequency range.
> 
> brucek


I have to strongly agreely with brucek. 

For several months I tried to make it work and I argued with those like brucek, but ultimately I found that they were right. Granted, I could get a certain frequeny range in the MBM to sound slightly better, but it also squashed other frequencies.


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## weverb (Aug 15, 2008)

Could he use the Paradigm X-30 to adjust the phase between 0 and 180? Would it really help much?


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## brucek (Apr 11, 2006)

> Could he use the Paradigm X-30 to adjust the phase between 0 and 180?


He could, but it adds a somewhat unnecessary device in the chain. The distance control of the receiver would work as well.

brucek


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## weverb (Aug 15, 2008)

brucek said:


> He could, but it adds a somewhat unnecessary device in the chain. The distance control of the receiver would work as well.
> 
> brucek


I am not familiar with his receiver. I know my NAD will not let you adjust any type of sub distance. You can only do the mains and surrounds.


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## brucek (Apr 11, 2006)

> I know my NAD will not let you adjust any type of sub distance


Really, I've never heard of such a thing. How does NAD propose that you set the sub distance? Are they relying on a subs phase control?

brucek


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## weverb (Aug 15, 2008)

brucek said:


> Really, I've never heard of such a thing. How does NAD propose that you set the sub distance? Are they relying on a subs phase control?
> 
> brucek


According to page 17 of the T754 manual, you can only set a distance for the front (both mains, cannot do individual front speakers), center, surround, and back (rear center). :huh: So I guess you have to rely on the the subs phase control. :thumbsdown:

http://nadelectronics.com/img/manual/NAD-T754-EN.pdf

Looks like the higher end models like the T775 let you set the sub distance.


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## jdeanmc (Aug 26, 2008)

weverb said:


> You are always welcome to come take a listen. :bigsmile: I can smoke us some ribs/brisket/pulled pork or grill up some fillets. :meal: Just PM me for address and you can plan on taking the family to Disney too. It's just 1.5 hours away.
> 
> 
> 
> It means you are on the right track! There has to be some good stereo shops within 1-2 hours drive from you? I know there is a guy in Alabama currently building an IB ht room. :nerd:


Great A free place to stay as well as free ribs one night,brisket the next,then fillet!!!i wouldnt want to impose:heehee:
seriously we have thought of going to Disney,probably be next year though,however if,on vacation i even brought up this home theater obsession,i may be looking for a ride back home!!!
My Avr is the Yamaha rx-v1800,it does have distance settings for the subs,ive changed it from 1 foot to about 20 feet and the above graphs seem to be as good as i can get,i think its currently at about 4-5 feet.
Maybe i jumped too soon when i grabbed the Mbm,i had less of a handle than i do even now on sub setup,not that i now know what im doing ,by any means but i probably was premature on adding more in the equation.
Boy info is hard to come by on that Velodyne sub!!!wondering if it would "fill"the room better than the Hsu?I really like the Ho but im always ready to swap something out
As far as mains slope.I have no idea i'd have to make a call i suppose to Klipsch.They're Klipsch Rf-3II's
Dean
P.s.you do charcoal not gas right?:scratch:WOW ,free food and then i complain about how you cook it!!!


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## weverb (Aug 15, 2008)

jdeanmc said:


> P.s.you do charcoal not gas right?:scratch:


Gas is what you get after eating too much! :rofl2: I use charcoal to get things started and then just use wood (oak, hickory, apple, cherry, etc.) from there on out. I want to try this next:

http://www.bbqaddicts.com/blog/recipes/bacon-explosion/

:meal:


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## jdeanmc (Aug 26, 2008)

weverb said:


> Gas is what you get after eating too much! :rofl2: I use charcoal to get things started and then just use wood (oak, hickory, apple, cherry, etc.) from there on out. I want to try this next:
> 
> http://www.bbqaddicts.com/blog/recipes/bacon-explosion/
> 
> :meal:


Well i dont mean to get us too far off topic but it seems we have 2 of the same passions!!!
I don't hate the looks of that at ALL!!!!
Dean
Btw Decatur is home to Chris Lilly and Big Bob Gibsons,ever heard of them?


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## weverb (Aug 15, 2008)

jdeanmc said:


> Well i dont mean to get us too far off topic but it seems we have 2 of the same passions!!!
> I don't hate the looks of that at ALL!!!!
> Dean


Let me guess, or at least if I were you, you go to Big Bob Gibson's BBQ all the time!


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## jdeanmc (Aug 26, 2008)

weverb said:


> Let me guess, or at least if I were you, you go to Big Bob Gibson's BBQ all the time!


Actually.No.haven't been in probably 2 years!I prefer to go home from work,do my own grillin' and then
go downstairs and try to figure out these confounded speakers!!!!
We moved about 2 years ago into the house were in now and danged if i hate leaving!!!(first house with a basement/Ht room)we havent been out to a movie in probably 2 years as well.
Dean


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## Synthsayer (Dec 19, 2007)

Very nice room! 
I see you have 2 traps; one on each side of the room. You may want to give some thought to using a couple of more of them, or repositioning the ones you have. Consider the wavelengths and amplitudes you are trying to control. Two traps just wont do it.
It appears that your sofa could be in a null area where the dimension of one area of the room changes to a smaller area where the rest room is located at the back of the room.
The sofa looks like it cannot go further back into the room so consider moving it closer to the front speakers in 6 inch increments. If this changes the distance between your listening point and the front and center speakers to where you are 11.5 feet from fronts and centers, just move the sub and rear surrounds in or out 6 inches so everything is offset by 6 inches. Then set the LR Front and center speaker distance at either 11 feet or 12 feet and the sub and rears using the same method and use whatever sounds the best for you. Experiment with both settings and listen to one for about 30 minutes, and then switch to the other after another 30 minutes. Take a break and have dinner or do something else for about 30-40 minutes to prevent ear fatigue and go back to see if everything still sounds okay.
Also, remember that wine or any alcohol will make getting the right setting much more difficult. Get everything set up then have a nice drink if you are so inclined.
I would bet that if you moved the sofa to 12 feet, brought the front L+R towards each other about 1-1.5 feet, then added a floor to ceiling 6" thick corner bass trap in the corner where the treadmill is you would get very good results. You could put another bass trap or two in the back of the room, too. In fact, more bass traps in the back section of the room and the corner where the treadmill are may solve almost all of your problems.
The VTF-3 Subwoofer looks very nice and should give you excellent results. Ported subs tend to be more problematic than sealed enclosures when it comes to phase and group delay. With the ported systems multiple impedance peaks affect the amplifier load and acoustic output of the sub at frequencies where the impedance peaks exist.
Best regards.


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## jdeanmc (Aug 26, 2008)

Synthsayer said:


> Very nice room!
> I see you have 2 traps; one on each side of the room. You may want to give some thought to using a couple of more of them, or repositioning the ones you have. Consider the wavelengths and amplitudes you are trying to control. Two traps just wont do it.
> It appears that your sofa could be in a null area where the dimension of one area of the room changes to a smaller area where the rest room is located at the back of the room.
> The sofa looks like it cannot go further back into the room so consider moving it closer to the front speakers in 6 inch increments. If this changes the distance between your listening point and the front and center speakers to where you are 11.5 feet from fronts and centers, just move the sub and rear surrounds in or out 6 inches so everything is offset by 6 inches. Then set the LR Front and center speaker distance at either 11 feet or 12 feet and the sub and rears using the same method and use whatever sounds the best for you. Experiment with both settings and listen to one for about 30 minutes, and then switch to the other after another 30 minutes. Take a break and have dinner or do something else for about 30-40 minutes to prevent ear fatigue and go back to see if everything still sounds okay.
> ...


Thanks,
I have in fact added some traps since the picture was taken.i now have 2 on each side wall and 2 on the rear wall however only the two on the rear are 4 inch the others are 2inch.I have some oc703 left so i will redo and add some panels.The sofa also has been moved up slightly but i dont remember what the measurement is now also the audio rack is now in the room behind the tv which opened up the front wall and the mains are now about 2 feet closer together.
I actually got some uhaul golf club boxes,12x12x48 i think,stuffed them full of insulation and placed one on top of the other in each rear corner and all along the ceiling,wall union on the rear wall and didnt really notice any difference.the wife really didnt just love the look of this so now their just taking up space in the garage.basically i was trying to imitate a soffit trap.
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> I actually got some uhaul golf club boxes,12x12x48 i think,stuffed them full of insulation and placed one on top of the other in each rear corner and all along the ceiling,wall union on the rear wall and didnt really notice any difference.


You could possibly reuse that insulation and make some diy bass trap panels.


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## jdeanmc (Aug 26, 2008)

weverb said:


> You could possibly reuse that insulation and make some diy bass trap panels.


i wasnt aware this would be effective in a bass trap ,its r-25(i think)i thought i had to use the oc 703 panels?do you have any links showing a diy build using this?i guess im wondering how much to stuff in and how to hold it in place?
Thanks
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> i wasnt aware this would be effective in a bass trap ,its r-25(i think)i thought i had to use the oc 703 panels?do you have any links showing a diy build using this?i guess im wondering how much to stuff in and how to hold it in place?
> Thanks
> Dean


No problem Dean. All of my traps so far have been made from R-30. They are my current ht project. Here is picture of my biggest trap made from 1"x6"'s.



I have also done some nice tri-corner ones too.



But here are some links for you.

http://www.geocities.com/jonrisch/a1.htm
http://webpages.charter.net/jdgeisen/BassTraps/BassTrap1.htm
http://www.bobgolds.com/Absorber/home.htm
http://geekwithfamily.com/2006/09/22/audiophile/how-to-build-jon-rischs-diy-acoustic-panels/
http://www.haoleb.com/acousticpanels.htm

I am going to try and build two ceiling clouds and two small "super chunck" style traps using Roxul material from ATS. I think I will be done after that. The wife has not been to happy and has started calling our living room the "Enterprise" from Star Trek due to the four triangle shaped traps. :sad2:

As you can see. You can get very creative in hiding, placing, and constructing sound panels. Have fun and try thinking outside the "golf club box"! :bigsmile:


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## jdeanmc (Aug 26, 2008)

Sorry for the delayed response.
Those are nice.great job on the corner traps.
I appreciate the links,i will look into adding more traps,im actually pretty pleased with my sound now.i still would like to move the mbm from behind the lp though,it seems no matter where i set the xover point its still too easy to locate.i was thinking of co locating it with the ho or moving it down around the same side wall as the ho and seeing if that would smooth things a little.
Ill be sure to mark the spot where it is now as its not bad and i really am pleased with the overall sound otherwise.
Thanks
Dean


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## weverb (Aug 15, 2008)

jdeanmc said:


> Sorry for the delayed response.
> Those are nice.great job on the corner traps.
> I appreciate the links,i will look into adding more traps,im actually pretty pleased with my sound now.i still would like to move the mbm from behind the lp though,it seems no matter where i set the xover point its still too easy to locate.i was thinking of co locating it with the ho or moving it down around the same side wall as the ho and seeing if that would smooth things a little.
> Ill be sure to mark the spot where it is now as its not bad and i really am pleased with the overall sound otherwise.
> ...


Hey Dean,

Glad to hear your are pleased with the results so far.


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