I'm custom building a dedicated home theater in my basement (with the assistance of my dad, who is a contractor, and an AV contractor, who handled the wiring only). I've been trying to read up on acoustics, here and elsewhere, and- well, I have to admit I'm a bit lost. So, yes- another new guy asking questions that may be irritating... Please bear with me...

I'd like to custom-build acoustic panels for the theater, but am unsure of the best/most effective approach. It seems that Linacoustic RC and batting are the materials of choice, but there's a great deal of variety to the approach. Barring hiring someone to do it (which would likely end up outside of my budget and cause my wife to divorce me)- what's the generally accepted best approach? Are there specific resources (or even threads) that anyone would recommend?

Again, sorry for the basic questions, and thanks in advance for any assistance folks can offer.

You may have already started on it, but obviously the acoustical treatment sticky is the best start:

http://www.avsforum.com/avs-vb/showthread.php?t=255432

At some point or another, most of the hardcore builds tackle the accoutic treatment issue. I'd suggest starting down some of the high profile threads like Sandman's or swithey's.

Acoustic treatment does seem to be one of the more difficult areas to tackle and is linked tightly with so many other aspects of your room. I've been reading for 6 months or so and have only just started to figure it out.

At any rate, welcome and good luck from a fellow newbie.

-Aaron

Thanks- read through the stickied thread (one and a half times, actually)- and am still feeling pretty clueless. :)

I'll keep digging...!

Just noticed another thread bumped back to the top on fabric frames:

http://www.avsforum.com/avs-vb/showthread.php?t=487747

Are you asking how to make panels? depends on what design you want, or are you asking where you put them? in which case while there are certain basic things like treating the screen wall and all your first reflection points, will vary as to what else you need and will be based on the specific room.
Also are you looking to do sound containment in this room? or to acoustically treat the room for the sound quality within? because they are two different things and both are important for different reasons. On the sound containment it sounds like it may be too late for you, but if not there is a LOT to do there. If acoustic treatment then you need to plan for those things I mention, and then work on the rest, absorption, bass traps etc. once you have the basic room finished and know what the exact problems are. Of course what materials you use to finish and furnish will impact on that as well.

We've already done some work on sound containment; I'm using insulation and double drywall. Not perfect, but better than nothing... My bigger concern is acoustic treatment.

I think I've got the basics down as far as the panels are concerned. I understand (generally) where i'd need to put panels (first reflection point, etc.)... I also had read the thread referenced above; that approach seems more extreme (as far as using panels on the whole room), but that may just be my lack of understanding. I guess that leads to my main question.

I've seen a lot of people saying that absorbers (e.g. Linacoustic) should be used "at/below ear level," but that batting is used above. Others are using linacoustic panels over the entire room. Still others are using rigid insulation. I know that there's no single (or easy) answer, but this is the general area where I'm confused.

I've got an irregularly shaped room, so I'm trying to be thoughtful about the acoustics. Would folks recommend that I wait until the room is finished? I know where the speakers will be placed, as well as (generally) where the seating will be located.

Well if you can give a diagram of the room, with measurements, the speaker placement, and your seating, screen location and size etc. that would help in responses.

But I can say this about the acoustic issues you mentioned. I have not seen any that I recall that have used absorbtion on the entire room. You mention using absorption, [ such as Linacoustic for example] to just above ear level , for each row, and then using batting, [more of a difusion] above that, those that want a uniform look of panels all over the walls do this. you use the batting more so that your top panels have something in them and so look uniform than because you need the batting. you can also do the absorption to above ear level then leave painted walls as well, or some form of decorative treatment that sort of splits the difference, which is what I did on my art deco style theater. If you were to use the absorption on all walls floor to ceiling you would end up with a room that was too "dead".
Does that help the confusion any?
As I say include that basics in your plan for sure as you build then make your final acoustic modifications once the rest of the room is done. Remember the room itself and it's treatment is more important to the sound you end up with than the equipment you put in it. you could use the most expensive speakers out there, they would still sound like crap in an untreated room and more inexpensive speakers will always sound their best in a well treated one.

Be sure to continue reading all you can on ALL the aspects of theater construction on here it is the best education, and money saver you can find anywhere.

There are two BASIC approaches I've seen. (several approaches, especially if your room is tested by a pro to determine what type of treatments you need and where to best satisfy the acoustic characterizations of your room. But, these two seem relevant when you DIY your treatments). I'm NO EXPERT, just from what I've read over the last few years.

1) Linacousic or Rigid Fiberglass from floor up to ear level all the way around the room (Except in the front, and a portion of the sides, you do the entire wall. This will take care of the first reflections too). As McCall said, the batting above is used so that your walls are even top to bottom (batting on top, linacoustic on the bottom). This way, you can cover the ENTIRE wall with fabric and see no differences in thickness from top to bottom. It will look pleasant and symmetrical top to bottom, but only absorb at the bottom. The batting will also absorb the very high frequencies which should help with the overall reverberation of your room, but won't do anything for the mids like the Linacoustic or Rigid Fiberglass will. As McCall said, many choose to put Linacoustic on the bottom and cover it with fabric, while just painting the top. Then installing a chair railing between the two sections for a nice clean look.

2) Cover the front wall from floor to ceiling with Linacoustic (or Rigid Fiberglass). Use the "Mirror" technique and place Panels of Fabric covered Rigid Fiberglass on the ceiling and the side walls at the First Reflection points.

I have number 2 and the sound difference in my room compared to no treatments is AMAZING!!. I used Knauff 3pcf Rigid FiberGlass Panels Covered with fabric.

Oh...don't forget bass traps in the corners.

Thanks (again) for the response. Yes, that helps quite a bit.

I'll post the drawings and my equipment list when I get home tonight.

Equipment List:


Sony VPLVW-50 1080p Projector
DaLite 92" Contour Screen
Denon AVR4306 HD Receiver
SpeakerCraft AIM LCR Front Speakers (3)
SpeakerCraft Tantra TS 12 Subwoofer
SpeakerCraft Surround Speakers (4)
Sony BDP-S1 1080p Blu-Ray Player
MX-3000 Remote w/ base station
Lutron Lighting Controller (w/3 dimmer switches
XBox 360, PS3, Wii
HD Cable Box


(Was going to post an image, but seems I can't do it until I have five posts... Images coming soon. :))

Okay, have five posts now... :p

Here's the general layout of the room (the red boxes are the current locations of the speaker boxes and subwoofer):
http://i86.photobucket.com/albums/k89/sagestl/HomeTheater1.jpg

If it were me, I would make some modifications to the layout.

1) I would cut back the 4'0 wall by the wet/bar as far as possible
2) I would put in a single row of 4 seats just slightly in front of the current position (i.e., in front of the wet bar)

That would allow you to center the screen on the wall and go bigger as well.

Is it possible to put a door on the right wall where you currently show a couch? If so, then you could move your back wall forward and put a row of 3 seats on your riser (since you wouldn't need access from the back)

Anyway, just some thoughts for you - they may not be practical given the layout in the rest of your space though.

If it were me, I would make some modifications to the layout.

1) I would cut back the 4'0 wall by the wet/bar as far as possible
2) I would put in a single row of 4 seats just slightly in front of the current position (i.e., in front of the wet bar)

That would allow you to center the screen on the wall and go bigger as well.

Is it possible to put a door on the right wall where you currently show a couch? If so, then you could move your back wall forward and put a row of 3 seats on your riser (since you wouldn't need access from the back)

Anyway, just some thoughts for you - they may not be practical given the layout in the rest of your space though.

The good news is that only the framing and AV wiring has been completed for the room so far, so I have at least some flexibility. As such- suggestions are welcomed and appreciated.

The 4'0" wall isn't built yet, so I have the option of cutting it all the way back to the edge of the cabinets. What's the reason for the suggestion? The main reasons I wanted the wall longer was to hide the wet bar from the main rows of seating, and to better control any noise from the fridge.

I was considering moving the front row forward- but I didn't want to get it too close to the screen. It's currently at 12' (if I recall correctly); I'd have to move it forward to about 8' to get another recliner in. Moving the seats forward also creates more space in the back of the room; I'm not quite sure what to do with that space already. Anyone have thoughts? Walling it in isn't really an option, as the speaker boxes and wiring for the rack are already in place.

I've already had the wiring completed for the front speakers, and have already bought the screen- so I'm pretty much tied down there. I'd considered going bigger, and centering on the wall- but I didn't want any seating in the back to have a completely off center (or cut off) view of the screen. It's not shown here, but I may end up putting additional seating behind the second row if I end up having room- but that's a future project.

Unfortunately, I can't put a door where the couch is located- the basement stairs are there, so I'm pretty much stuck with the location I have as the only feasible location.

I'm want to use Linacoustic panels (or something) in the room, but, again, I'm worried that the acoustics will be messy due to the shape of the room. At the very least I'm going with double drywall, and was just pricing Green Glue last night. Any other thoughts about what might help?

The good news is that only the framing and AV wiring has been completed for the room so far, so I have at least some flexibility. As such- suggestions are welcomed and appreciated.

The 4'0" wall isn't built yet, so I have the option of cutting it all the way back to the edge of the cabinets. What's the reason for the suggestion? The main reasons I wanted the wall longer was to hide the wet bar from the main rows of seating, and to better control any noise from the fridge.

I was considering moving the front row forward- but I didn't want to get it too close to the screen. It's currently at 12' (if I recall correctly); I'd have to move it forward to about 8' to get another recliner in. Moving the seats forward also creates more space in the back of the room; I'm not quite sure what to do with that space already. Anyone have thoughts? Walling it in isn't really an option, as the speaker boxes and wiring for the rack are already in place.

I've already had the wiring completed for the front speakers, and have already bought the screen- so I'm pretty much tied down there. I'd considered going bigger, and centering on the wall- but I didn't want any seating in the back to have a completely off center (or cut off) view of the screen. It's not shown here, but I may end up putting additional seating behind the second row if I end up having room- but that's a future project.

Unfortunately, I can't put a door where the couch is located- the basement stairs are there, so I'm pretty much stuck with the location I have as the only feasible location.

I'm want to use Linacoustic panels (or something) in the room, but, again, I'm worried that the acoustics will be messy due to the shape of the room. At the very least I'm going with double drywall, and was just pricing Green Glue last night. Any other thoughts about what might help?Do you have a diagram that shows the rest of the basement? That might allow us to think of some things you may not have considered.

Personally, I would not put the wet bar there. The noise from the fridge is going to annoy you, wall or no. I have my wine fridge outside my theater and when the doors are open its very audible. And its about 15' away. Maybe you can find a really quiet one, but I'm guessing it will be pricey. Any reason you can't put the wet-bar at the back of the room? If you remove the wet-bar I think you open up a lot of good options. You can put your first row partially against that wall where the wetbar would be and allow walking room around the left hand side, for example. Anyway, I would think carefully about having the wet bar there.

Why not put a countertop with Bar stools behind the back row? If you put your wetbar back there you'd have a nice little party zone. I think those would be more usable than the couch you currently have against the right wall - I don't really think that is a practical place for seating.

As for your current seating, I wouldn't go any further back than 12' if it were me. That's about 1.6 x Screen width. Everyone is different, but I've found that people like to sit closer than I thought they would. I have temp seating right now while I wait for my seats to come in and we've moved it around to see where we like it. Most people like it around 1.2x is what I find. Some like it even closer than that, but not many like it further back.

Is it possible to bring that pocket door forward at all?

Double drywall and Green glue are not going to help you with room acoustics, only sound isolation. I hired BPape to tell me what treatments I needed in my room. If you can do that I think its money well spent. Consider like another piece of audio gear - it will certainly affect the sound more than new speakers or a new receiver. If you can't do that, then you should plan to at least put in panels at the first reflection points and build in some bass trapping. The acoustic treatments master thread (sticky) is a good start.

I agree about the refrigerator and about losing or moving the bar out of the room proper. I also think that with that size screen you are already going to find it very small from the second row, and it would be tiny from a third row.

I also think that with that size screen you are already going to find it very small from the second row, and it would be tiny from a third row.I agree. He already has his screen so I think moving the front row forward and losing the wet-bar is the way to go. Then he can pull his 2nd row up so the sidewall doesn't interfere with the sightlines.

Another option is to put a wall along the back of the 2nd row and separate the equipment room/wet bar from the rest of the theater. That would certainly help with sound isolation and ambient noise from the equipment and bar fridge. Not sure what the door options are without seeing the rest of the basement though....

I’ll post some information regarding the rest of the basement so that it’s in perspective.

I’d rather not have the wet bar (limited as it is) there, either, but unfortunately that’s really the only place where I can get access to a drain pipe in the room. There’s really no other convenient place in the entire basement. I’m not dead-set on keeping the wet bar, but it would be a nice addition.

Our AV contractor has already framed in and wired for the speakers on the front wall (and I’ve already bought the screen), so I can’t really make any changes to them. Your point about the additional row is well-taken, though. Interesting idea to move the seating over to the right… The fact that I can’t really re-center the screen means I can’t move it over too much, though, without throwing the set-up off-center. I’ll tinker with the placement to see what makes sense- I agree that I might need to move both rows up a bit. I'll see if I can't add another seat to the first row, too- but I'm worried about having any of that seating too far over to the right.

The couch on the right wall is a WAF concession. My wife wants a couch, so I threw in a couch. :)

The countertop idea was one that the AV guy brought up- I really like the idea. I can’t put a wet bar back there, though, without ripping up the concrete (about 20 feet- a lot of work and expense).

It’s not possible to move the pocket door- that’s really the only possible (or, at least favorable) entry to the room, based on the basement (

Sorry- keep using the wrong word (acoustics instead of isolation). I’m open to spending some money on acoustics (and isolation), but I don’t think I can afford a consultant. I’ve read the acoustic treatments thread twice now, and that was what caused me to ask for input in the first place- a lot to digest there.

For better or for worse- the entire back of the room is currently wired for both the AV equipment and the speakers. I’d have to go to great expense to change it. I thought about closing off the back of the room (in hindsight), but I think I’m stuck with it. Now I'm really regretting some of the initial decisions we made, in retrospect. :(

If you are going with recliner seating, you can get love seat or couch style that still recline, maybe then you can lose the couch.
THe regretting thing is exactly why it is so necessary to read here for several weeks to months before you do anything, unfortunately most of us have started something before we even discover the forum.

HEHE you can always sell the screen :p nothing is set in stone until the drywall goes up but that can even be torn down :rolleyes:

I had bought a 104 wide 16:9 screen before I even got started framing bad idea :mad: I got to digging even deeper into the threads and reading and decided to change to a 2:35 CIH screen after seeing some awsome screen shots and CIH rooms. I have since purchaced a 144" wide 2:35 SMX screen :D

NEVER purchace anything till everything is written in stone ;) Anyone in need of a 120" 16:9 fixed screen :o

If you are willing to spend on treatments and isolation i would highly recommend you speak with bpape he is very very reasonable rates wise and will most likely save you money not having to treat areas you dont need and not wasting your resources on things that really dont make sense. I think you will be shocked at how reasonable his rates are, I know i was. otherwise i would agree with the other guys with moving up the rows and trying to go a little wider on the first row. you will also want to move your side rear speakers up. either in line with the front row to maximize sound there or between the rows to split the difference? are you using the new speakercraft dipole rears or inceilings like aims on sides and rears?

If you are going with recliner seating, you can get love seat or couch style that still recline, maybe then you can lose the couch.
THe regretting thing is exactly why it is so necessary to read here for several weeks to months before you do anything, unfortunately most of us have started something before we even discover the forum.

Yes, that's where I'm at- we're already several months into the project, and I just discovered the forum last week, I'm afraid. :(

If you are willing to spend on treatments and isolation i would highly recommend you speak with bpape he is very very reasonable rates wise and will most likely save you money not having to treat areas you dont need and not wasting your resources on things that really dont make sense. I think you will be shocked at how reasonable his rates are, I know i was. otherwise i would agree with the other guys with moving up the rows and trying to go a little wider on the first row. you will also want to move your side rear speakers up. either in line with the front row to maximize sound there or between the rows to split the difference? are you using the new speakercraft dipole rears or inceilings like aims on sides and rears?

I'll check out bpape (user name?)... I'm convinced regarding the seating- going to see how things work out tonight.

I'm using the new dipole rears on the back walls, yes. For better or for worse, the equipment is already all purchased... :o The speaker mounts are all wired already, as well.

I'm very interested in hearing what bpape suggests for your room because it is nearly identical to the dimensions of my room (mine is 13 x 28). The main difference is that I don't have the little bump out in the front but just a constant width.

I plan on building cabinets and a wet bar at the back of the room with a bar behind the second row of seating. I'm concerned that putting the rears in the very back of the room will be less than ideal. Sounds like you are pretty much pinned into that decision without ripping out some work that's already been done so it will be nice to hear what the experts say about this setup.

I'm trying to convince the spouse to allow me to build a wall behind the second row which would at least suffice to put the rears on as well as help with treating my room. She wants the big open, entertaining area with no wall. FWIW, I feel your pain on the couch too....have these ladies never sat on a Berkline :)

Looking forward to what you come up with.

-Aaron

LOL! Yeah, I'm going with Berkline recliners, too. But my wife's feedback was "What if I want to lay on the couch and watch a movie?" She very specifically asked for a couch- and I wasn't about to say no. :)

LOL! Yeah, I'm going with Berkline recliners, too. But my wife's feedback was "What if I want to lay on the couch and watch a movie?" She very specifically asked for a couch- and I wasn't about to say no. :)
That is what Living rooms are for, or bedrooms etc.
Of course someone here had a hot tub to sit in and watch a movie so I guess it takes all kinds. :D

I'm using the new dipole rears on the back walls, yes. For better or for worse, the equipment is already all purchased... :o The speaker mounts are all wired already, as well.

Sorry to burst the bubble, but dipoles are a VERY bad idea for rear speakers. You want direct sound from the rears, NOT the reflected sound you'll get from dipoles. It'll mess up your sound field horribly and movie sound will be a mess.

-drin

That is what Living rooms are for, or bedrooms etc.
Of course someone here had a hot tub to sit in and watch a movie so I guess it takes all kinds. :D

No argument from me- but I'm not about to reject my wife's one request for the room outright... :)

That being said- if it throws everything into disarray, I might be able to get rid of it. Even so, centering the screen on the front wall really isn't an option anymore (at least not without a great deal of expense and hassle).

Sorry to burst the bubble, but dipoles are a VERY bad idea for rear speakers. You want direct sound from the rears, NOT the reflected sound you'll get from dipoles. It'll mess up your sound field horribly and movie sound will be a mess.
This is simply not the case and does not represent the environment for which the movie sound track is mixed.

Okay, speaking theoretically- I can radically change the design. I paid someone to do all the wiring, so I'd be out the money for that, but I guess I can rewire it myself (if I can find the time). We'd also need to reframe.

This design is much smaller than the first (obviously), but results in much less "dead" space. It also eliminates the irregularity of the shape of the room. The overall shape of the room is pretty much going to have to stay the same due to the surrounding structure. There's still going to be an HVAC duct along the right side of the ceiling, but that's it. (Please ignore the specific placement of speakers- I can adjust those. Just getting input on the idea overall.) This would also theoretically allow me to put a bar on the outside, if I can figure out the drainage (and it's not to cost prohibitive).

http://i86.photobucket.com/albums/k89/sagestl/Theoretical1.jpg

So, in everyone's opinion:

Does this make more sense, generally? Any specific concerns?
Is this new theater too small (15X17), or the seating too close (6-7 feet)?
Understanding that I already paid quite a bit of money for the wiring- is it worth the time and money to change it?


Looking for honest opinions here. Honestly- I'm a bit depressed that I'm having this discussion now, and not a month ago (before the wiring was done) or two months ago (when the framing was completed), but that's my fault- and better now than when it's all done. For what it's worth- my wife said she didn't care if I changed anything, as long as it didn't cost anything and it didn't hold up the construction too long. :eek:

I love the new plan I think you would be much happier with that layout. Ill be interested to hear what the experts say. I think it would be worth the expense and time and just be happy you found it now lots easier to change now then in another month or two. enjoy

Just my .02.

I think this plan is better accoustically, it is centered and has better overall seating. I think you've made the room too small and I would consider moving the wall behind the second row of seating back another 3 or 4 feet and put the equipment rack facing in to the room (don't worry about re-wire) most of what you are doing is shortening runs and it is pretty easy at this point of construction. You then also don't have so close to a square room. You could put some storage along the remainder of the wall that the equipment rack does not occupy.

I would flip your long counter you have on the right against the very back wall (lowest in the diagram and then put the bar out in front of it like you have it, but starting off of the left wall.

I won't be able to extend the back wall without ending up with the irregular shaped room again. The furnace and water heater are on the lower right corner, so I can't expand the back wall any further if I take it back. I'm okay with the irregular shape in that scenario- but I wouldn't be able to center the back channels any longer (assuming that they're at the same room depth).

Here's what I mean:
http://i86.photobucket.com/albums/k89/sagestl/Theoretical2-1.jpg

(The furnace/water heater are in the blue area.) I can make the room smaller to get rid of the irregular shape- but increasing it beyond the current design puts me in pretty much the same boat as before.

What about ceiling mounts?

Also, if you do have the water heater over in that right hand cutout, then forget what I said about the bar. If you can keep the wet bar, then I would keep the sink.

Already have purchased (signed contract for, actually) all of the speakers. I don't know what kind of hassle it would be to change them. Frankly, I don't even want to ask until I figure out what other changes, if any, I am going to make- better to do it all at once if I need to try to make changes.

How about some real photos of the intended area. would like to see how the furnace and water heater factor in.

This is simply not the case and does not represent the environment for which the movie sound track is mixed.

OK, my mistake. I thought that was the case.

Is it BIpole speakers that are bad for rear surrounds?

-drin

I don't think 15'7" is long enough to incorporate 2 rows of seating. Acoustically, you don't want seats flush against the back wall, which I'm afraid you'll have in your case. My room is 19' long and I barely have enough room for two rows of seating with about a foot and a half to spare behind my rear seats. I believe my front row is TOO close to my 100" screen at 10' back. It's great for HD, but standard DVDs, I see too much pixelation. Even if you have a great picture that close to your screen, it may still be difficult to get the 2nd row in and be out from the wall.

what I suggest is that you do move the back wall back as you need the room behind the seating. AND since you have the speakers already, What are they by the way?,
use a THX configuration for them that would mean the two rears are centered and right next to each other in the back They would actually be behind that second seat in the second row, give yourself as much room there to move em back as you can.

I have two feet behind my second row and the rears are there so they are about a foot behind your head but tweeters are at 60" floor level, not riser, but floor level. This works but would have been better if I had a couple more feet behind me to work with.

use a THX configuration for them that would mean the two rears are centered and right next to each other in the back They would actually be behind that second seat in the second row, give yourself as much room there to move em back as you can.
Let me address this misconception and Drin's question.
First, the "THX configuration" as suggested by McCall can only be used with a THX certified surround processor which supports this configuration. In 'movie' mode, a THX processor will decorrelate these two channels creating a phase interference to prevent localization of the rear speakers and a wider, non-localizable rear effects field. This was developed (in part) by THX to address the fact that multichannel music is not recorded to any standard and it would provide the listener the ability to switch between a localized mode and non-localized mode when required or desired. If you do not have a THX certified surround processor which supports this type of processing, this would be a disappointing configuration.

Second, to Drin's question, bipoles are OK but not as well suited as dipoles. Bipoles are a better choice than monopoles for movie sound tracks unless you can get the nearest listening position about 15' from the speakers. Understand that movies are mixed on the presumption that effects arrays are being used for play back (as SMPTE reference final mix stages are configured). With an array, localization cannot be achieved. In our residential sized spaces, our desire is to recreate as close as possible the mix environment to hear exactly what the director heard and desired that we hear. The director did not, and indeed could not hear, or have, localization in the effects (sides or rear) channels. Such localization in a home (or other) theater would be a form of distortion.

Ok, sorry about that, all my stuff is THX certified so I didn't really think about that part of it.

In fact though I usually listen to stuff in one of the Logic 7 modes unless something is specifically heavy in special effects.

Second, to Drin's question...

Thanks Dennis, for your answer, complete and informative as usual. I understand now.


-drin