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Discussion Starter · #1 ·
Hello all...


Love and respect the folks on this site, have helped me so much in pre build prep. I am starting my DSX 11.2 CIH theater build with a 30k budget and wanted to gauge if there was any interest in me keeping a progress log and if folks would be open to giving some guidance as I have more money than sense but have a love of theater and music and saved my pennies and worked my butt off to get here. Any suggestions for doing a good journal would be appreciated as well.


If no one cares, I just don't want to put in the effort to post as I don't do any social network stuff normally but some of u guys really know your stuff and I could use the support.


T
 

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Quote:
Originally Posted by grasswaiting  /t/1470177/dsx-11-2-cih-theater-build#post_23250998


Hello all...


Love and respect the folks on this site, have helped me so much in pre build prep. I am starting my DSX 11.2 CIH theater build with a 30k budget and wanted to gauge if there was any interest in me keeping a progress log and if folks would be open to giving some guidance as I have more money than sense but have a love of theater and music and saved my pennies and worked my butt off to get here. Any suggestions for doing a good journal would be appreciated as well.


If no one cares, I just don't want to put in the effort to post as I don't do any social network stuff normally but some of u guys really know your stuff and I could use the support.


T

If you have $30k budget, but "more money than sense", then I suggest getting some Pro theater plans, then following them with input from people here.


Learning while doing is what many of us do here, but having a good foundation to work from ensures you a successful result.
 

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Discussion Starter · #3 ·
Thank you for the comment. I have read everything I can get my hands on, master handbook of acoustics (recommended here) etc. Attached is my basic room schematic, three walls are concrete, one drywall. Dimensions are 8hx18wx24l. The red dot is a post I am moving out of the way, already adjusted the structural by sandwiching some plywood to span the length up to code.


Thanks again for comments, really appreciate guys

 

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Discussion Starter · #7 ·
Well ordered up the 11.2 speakers and amps today, so I have about a month to finish this build so its ready when they get here. After looking at speakers and amps at all levels, I settled on sonus Faber Veneres (3-3.0 floorstanders for LCR, 4-2.0 bookshelfs for wides and sides, 4-1.5 bookshelfs for heights and rears), rogue audio atlas Magnum tube amp for L&R and 2-5150 butler 5 channel tube hybrid amps for the rest. The Fabers loved the tubes, not my fault! I'm still searching for the right sealed subs. There went 2/3 of my remaining budget fast! But doing good as I only have minor construction and already have the acoustic treatments and screen covered.


?'s

1)Can anyone provide guidance on whether I should put all 3 floorstanders behind the 12' wide screen (seating area 16ft back) or just the center and bring the L&R out farther for better staging, the angle recommendations put me right on the edge of the screen? (Thank u all for teaching me that horizontal center channel speakers are a compromise, I see the light now)


2)Also how far out is the minimum I can build the false front wall with front ported fabers?Chris at screen excellence said the Center Stage XD AT screen only needs a couple inches. I would like as tight as possible without killing the beautiful sound.


3) Last I was going to use all absorption on the front wall and first reflections with 2" of auralex foam over 2" of 703 fiberglass with 4" of air gap in modular 2x4 panels and large auralex/703 bass traps in the corner and use diffusion on back wall and rear sides as needed. Any one have comments here, wondering if I should use some diffusion on the front wall? (Auralex T-Fusors/1" of 703 in the cavity)


Will post picks of the room and hot chicks as this build progresses and to reward good comments. Will do a few starting pics tomorrow. Thx all
 

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Quote:
Originally Posted by grasswaiting  /t/1470177/dsx-11-2-cih-theater-build#post_23253469


Can anyone provide guidance on whether I should put all 3 floorstanders behind the 12' wide screen (seating area 16ft back) or just the center and bring the L&R out farther for better staging, the angle recommendations put me right on the edge of the screen?
I would put the L&R speakers 32" from the side walls (to get smoother frequency response). IF you get a couple of subs, place them 4' in from the side walls (same reason). Good choice on seating location (1/3 of room length).
Quote:
Originally Posted by grasswaiting  /t/1470177/dsx-11-2-cih-theater-build#post_23253469


I was going to use all absorption on the front wall and first reflections with 2" of auralex foam over 2" of 703 fiberglass with 4" of air gap in modular 2x4 panels and large auralex/703 bass traps in the corner and use diffusion on back wall and rear sides as needed. Any one have comments here, wondering if I should use some diffusion on the front wall?
I would stick with all absorbtion on the front wall so that no reflected energy interferes with the imaging in the front soundstage.
 

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Discussion Starter · #9 ·
Ok so tomorrow I am building a 2x4 stud wall 2ft on center to line the front concrete wall. This will allow 2" of Auralex foam, 2" of 703 and ~1.5" of air gap. I am going to use Velcro on the back of the Auralex and just tuck the 703 in the bays.


I am also running 4-20 amp circuits for all the gear as the butlers need 15 amp a piece. Just got a thank you letter from my PG&E rep for my vastly increase electrical bill. She came out and read the meter today and I took a photo. Pleasant, skilled woman.
 

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He said HOT babes, not artificial humans.
But seriously anything that says 11.2 will be interesting.
 

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Discussion Starter · #11 ·
Attached are some starting pics, work is in full swing. I just took some panorama shots in the basement. Framing and electrical going on over the next several days: 12 recessed lights, dimmers that work from a universal infrared remote, 4 20 amp outlets and dedicated breakers for the butlers and rogue tubes. I ordered the 2" 703 for the front wall, which will be 2" of auralex, 2" of 703 and 2" of air gap over the whole wall, that should make my 3 matching Faber Venere 3.0s sound clean.


Also, Faber wouldn't sell me 3, so I had to buy 4. I am going to list the fourth for sale on this forum if anyone is interested.


[/URL]
 

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Discussion Starter · #13 ·
Also my acoustic designer stopped by but she's a bit out there! She got a little salty sweet over the 11 fabers and full tube setup one the way though. The wife did not like her one bit, she looks harmless enough to me;/
 

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Quote:
Originally Posted by grasswaiting  /t/1470177/dsx-11-2-cih-theater-build#post_23253469


Well ordered up the 11.2 speakers and amps today, so I have about a month to finish this build so its ready when they get here. After looking at speakers and amps at all levels, I settled on sonus Faber Veneres (3-3.0 floorstanders for LCR, 4-2.0 bookshelfs for wides and sides, 4-1.5 bookshelfs for heights and rears), rogue audio atlas Magnum tube amp for L&R and 2-5150 butler 5 channel tube hybrid amps for the rest. The Fabers loved the tubes, not my fault! I'm still searching for the right sealed subs. There went 2/3 of my remaining budget fast! But doing good as I only have minor construction and already have the acoustic treatments and screen covered.


?'s

1)Can anyone provide guidance on whether I should put all 3 floorstanders behind the 12' wide screen (seating area 16ft back) or just the center and bring the L&R out farther for better staging, the angle recommendations put me right on the edge of the screen? (Thank u all for teaching me that horizontal center channel speakers are a compromise, I see the light now)


2)Also how far out is the minimum I can build the false front wall with front ported fabers?Chris at screen excellence said the Center Stage XD AT screen only needs a couple inches. I would like as tight as possible without killing the beautiful sound.


3) Last I was going to use all absorption on the front wall and first reflections with 2" of auralex foam over 2" of 703 fiberglass with 4" of air gap in modular 2x4 panels and large auralex/703 bass traps in the corner and use diffusion on back wall and rear sides as needed. Any one have comments here, wondering if I should use some diffusion on the front wall? (Auralex T-Fusors/1" of 703 in the cavity)


Will post picks of the room and hot chicks as this build progresses and to reward good comments. Will do a few starting pics tomorrow. Thx all

Using strictly absorption for the "first reflection" points has been pointed out numerous times to be a bad idea in other threads. Further, if these reflective areas are properly treated, there is no need for the use of either height or wide speakers. However, if you insist on using these unnecessary point sources, then you will need only absorption to deal with the boundary gain and SBIR that will invariably result from their use. In other words, you have to fix it in order to make it work, and believe it or not, they will not sound nearly as good as if there had not been a speaker there to begin with (assuming a properly treated side wall).


Speakers placed behind a screen will lose high frequency SPL at the listening point. In order to compensate for this, use a high quality DSP. Make sure you don't blow your tweeters though in the compensation process. Hope this helps!!
 

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Quote:
Originally Posted by SierraMikeBravo  /t/1470177/dsx-11-2-cih-theater-build#post_23261543


Using strictly absorption for the "first reflection" points has been pointed out numerous times to be a bad idea in other threads. Further, if these reflective areas are properly treated, there is no need for the use of either height or wide speakers. However, if you insist on using these unnecessary point sources, then you will need only absorption to deal with the boundary gain and SBIR that will invariably result from their use. In other words, you have to fix it in order to make it work, and believe it or not, they will not sound nearly as good as if there had not been a speaker there to begin with (assuming a properly treated side wall).


Speakers placed behind a screen will lose high frequency SPL at the listening point. In order to compensate for this, use a high quality DSP. Make sure you don't blow your tweeters though in the compensation process. Hope this helps!!

You all did my layout plan and I asked for front height speakers. I also have plans to use the material suggested on the first reflection locations, which is very expensive. So correct me here if am wrong.


You are saying using just absorption instead of the quest material it would be better? Just seems like a waste to spend so much on the quest material if only absorption will be more beneficial. But on the other hand....


You're also saying it will sound better with the quest panels if I unhook the front heights, correct?
 

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Discussion Starter · #16 ·
Quick poll based on Sierra Mike's comment. Can I drop to a 7.2 setup and lose the back surrounds and heights and still have a great experience?


I can save a bucketload of money. I am worried that Faber doesn't make dipole surrounds, if I lose the back surrounds I was concerned my sides would be too directional. Could I use bookshelfs to mimic dipoles by pointing one set forward (sides) and one backward (back) and would XT32 correct for this to make it work?


I put the 11.2 order on hold for a few days to get some thoughts here.
 

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In my humble:D opinion, stick to a 7-2 setup you will not be missing anything. And 7-2 I mean side surround whether or not bipoles/dipoles or front firing bookshelves. Make sure you use back surrounds that's the true way to go that'll give the sound as it is intendant .
 

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Quote:
Originally Posted by SierraMikeBravo  /t/1470177/dsx-11-2-cih-theater-build#post_23261543


Further, if these reflective areas are properly treated, there is no need for the use of either height or wide speakers.
How will 3 speakers placed at ear level in front of you deliver stable imaging above you? IF you feel that speakers are needed at the sides for stable lateral imaging and speakers are needed at the back to anchor sounds behind you, then why would you not need height speakers to image sounds above you?


The argument for wide speakers is the same as the reason to use a centre speaker: stabilize sounds that would have phantom imaged there anyway. Why use a centre speaker when good mains can throw a convincing phantom centre floating between those speakers? Imaging stability. Likewise, on good 7-speaker layouts, you can hear sounds floating between the fronts and sides. However, as you move, these phantom images move with you. Replacing those phantom images with speakers keeps them anchored at those locations, especially for listeners sitting outside the sweet spot. Just like with a centre speaker.
Quote:
Originally Posted by SierraMikeBravo  /t/1470177/dsx-11-2-cih-theater-build#post_23261543


However, if you insist on using these unnecessary point sources, then you will need only absorption to deal with the boundary gain and SBIR that will invariably result from their use. In other words, you have to fix it in order to make it work, and believe it or not, they will not sound nearly as good as if there had not been a speaker there to begin with (assuming a properly treated side wall).
Why would things like SBIR be a problem with heights and wides but not the other 7 speakers?
 

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Quote:
Originally Posted by sdurani  /t/1470177/dsx-11-2-cih-theater-build#post_23264826


How will 3 speakers placed at ear level in front of you deliver stable imaging above you? IF you feel that speakers are needed at the sides for stable lateral imaging and speakers are needed at the back to anchor sounds behind you, then why would you not need height speakers to image sounds above you?


The argument for wide speakers is the same as the reason to use a centre speaker: stabilize sounds that would have phantom imaged there anyway. Why use a centre speaker when good mains can throw a convincing phantom centre floating between those speakers? Imaging stability. Likewise, on good 7-speaker layouts, you can hear sounds floating between the fronts and sides. However, as you move, these phantom images move with you. Replacing those phantom images with speakers keeps them anchored at those locations, especially for listeners sitting outside the sweet spot. Just like with a centre speaker.

Why would things like SBIR be a problem with heights and wides but not the other 7 speakers?

Hi Sanjay,


I dont wantto derail this thread and start on Audyssey bashing rampage or Chris K said this or that. There has been plenty of discussion regarding DSX in other threads, and i dont wish to debate it further. This is my opinion, and I was one of the first to hear DSX some years ago in a private demo with Chris K and Luc. Bottom line, what I heard was exactly what I was told I would hear from a very well known acoustician...and I didn't care for it as I had just come from a lousy hotel room which had been treated properly and calibrated properly. The lousy hotel room was superior in sound quality in every way. DSX is not a new concept, and was tried many years ago in a different form. End result...the same.


So, here goes. THX speakers often use waveguides that limit vertical dispersion so that the proportion of floor/ceiling reflections to direct sound is maximized. The horizontal dispersion is increased to help alleviate the so called sweet spot, and increase dispersion for multiple seats. Further, while not as important, we can localize a source in the vertical with only a single ear, but in the horizontal plane, we need both for localization. So, I would argue that the vertical plane (the height speakers, is not as critical as the horizontal plane (wide speakers). Further, you will now often have to treat for SBIR issues with these speakers as they are often placed equidistant from perpendicular surfaces and in fairly close proximity to a tri-corner...not to mention boundary gain being so close to the wall (talking inches here). It is unavoidable unless you severely limit the frequency range or the speakers output. Now you will have to deal with that. Moving onto the horizontal speakers. Modern films take advantage of encoding spatial cues into the soundtrack. These "spatial" cues are not necessarily meant to be point source localized, but rather generally located in time and space in some particular direction. Part of the problem with having side reflections is that the path difference from the reflected sound and the direct sound leads to differences in timing. We are talking milliseconds here. The reflected sounds amplitude is often slightly lower in SPL than the direct sound, but it can be higher. In mid and lower frequencies, this leads to smearing of, especially, the dialogue. So, we absorb that to lower the amplitude a bit so that the smearing is reduced and the timing difference increases. Problem with that is, is that it eliminates the higher frequencies which greatly assist in those spatial cues. We have to preserve those frequencies and ideally diffuse them. If I put a speaker there now I have introduced a point source which is VERY localizable (the part I really don't like). Those side reflections should be enveloping and diffuse and seamlessly integrate the area between the front speakers and side surrounds. Properly positioned speakers, treatment and a calibrated room is amazing in this capability. I prefer to not be able to go BAM! It's ALL coming from right there! Yuck! Not to mention that speaker being right next to a wall since most rooms are width challenged introducing another source of boundary gain. I did not say boundary gain and SBIR were not problems with the other speakers, but why introduce more problems? I understand your argument Sanjay, but it is precisely that localization, which in my opinion, ruins the overall effect. Adding the proper treatment with diffusive properties provides for all seating and not just the sweet spot. In my opinion, you end up with a much more pleasing and enveloping soundstage.


Lastly, in my personal opinion, adding these speakers is costly, not particularly aesthetically pleasing and just plain unnecessary. My two cents.
 

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Quote:
Originally Posted by audiovideoholic  /t/1470177/dsx-11-2-cih-theater-build#post_23261550


You all did my layout plan and I asked for front height speakers. I also have plans to use the material suggested on the first reflection locations, which is very expensive. So correct me here if am wrong.


You are saying using just absorption instead of the quest material it would be better? Just seems like a waste to spend so much on the quest material if only absorption will be more beneficial. But on the other hand....


You're also saying it will sound better with the quest panels if I unhook the front heights, correct?

Absorption would NOT be more beneficial in my opinion. However it comes down to preference. I very much dislike DSX. I have been in many...many rooms properly treated, calibrated and laid out that sound superior to DSX. Again, that is my opinion. If you use the wide speakers (not the heights) I do not see the need for Diffusive treatment since the source has become quite localized...again only for the wides. You lose the advantage of the diffusion because of the point source. Now, if you don't use the wides, then it DOES become advantageous to use Diffusive panelling for the sides. Regarding the use of heights, please see my other post. I feel they are completely unnecessary. But, physics aside, we are really talking more about abstract concept here rather than concrete. I have a particular sound I enjoy, but it may not be quite the sound you enjoy.
 
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