New build and I want to do it right.....Help!

[CrazyCanuck75]

OK, here we go.

I am currently planning a dedicated home theater in my basement and this forum is where I will be coming to ask multiple questions of my fellow home theater enthusiasts over the upcoming months. I will need help with acoustic wall treatments, celling treatments, wiring, wall construction, flooring, lighting and many other concerns I will undoubtedly run head on in the future.

The room is planned to be 17' long x 11'1" wide x 8' high. The height and length are absolute and cannot be changed. however the width could be changed if need be.

My first questions are about wall and floor construction. As I said previously this is a basement build, so I have a cement/drywall wall directly behind the screen and another to its right. the back wall is a basic 2x4 interior wall and the last wall to the left of my screen is not built yet. The floor is cement.

My questions are:

1) Should I build a sub floor to help my subs produce better bass? If so how thick do i need it to be and do I need to lay insulation under it?

2) Should I build false walls over top of the two cement/drywall walls or is the drywall already acting like a false wall?

3) I have accepted the fact I will need to remove the drywall from the rear wall to insulate it, but can I use 4" thick acoustic panel's to fill in between the 2x4 studs and not replace the drywall? (Maybe cover the rear wall with some sort of acoustically transparent fabric over acoustic panel's).

I hope you guys and gals can help me with this as I am sure to have more questions to come in the future.

Thanks.

 

[CrazyCanuck75]

Hello..... is there anybody out there?

 

[GO-NAD!]

OK, here we go.

I am currently planning a dedicated home theater in my basement and this forum is where I will be coming to ask multiple questions of my fellow home theater enthusiasts over the upcoming months. I will need help with acoustic wall treatments, celling treatments, wiring, wall construction, flooring, lighting and many other concerns I will undoubtedly run head on in the future.

The room is planned to be 17' long x 11'1" wide x 8' high. The height and length are absolute and cannot be changed. however the width could be changed if need be.

My first questions are about wall and floor construction. As I said previously this is a basement build, so I have a cement/drywall wall directly behind the screen and another to its right. the back wall is a basic 2x4 interior wall and the last wall to the left of my screen is not built yet. The floor is cement.

My questions are:

1) Should I build a sub floor to help my subs produce better bass? If so how thick do i need it to be and do I need to lay insulation under it?

2) Should I build false walls over top of the two cement/drywall walls or is the drywall already acting like a false wall?

3) I have accepted the fact I will need to remove the drywall from the rear wall to insulate it, but can I use 4" thick acoustic panel's to fill in between the 2x4 studs and not replace the drywall? (Maybe cover the rear wall with some sort of acoustically transparent fabric over acoustic panel's).

I hope you guys and gals can help me with this as I am sure to have more questions to come in the future.

Thanks.

First thing I would ask is, how old is your house? If it's new construction, I'd wait a year or two, just to make sure it has settled and no foundation cracks appear.

If it's at least that old, then you can proceed. How dry is that basement? I've seen people put just vapour barrier, underlay padding and carpet down directly on the concrete. I'm quite leery of that. I'd lay an insulated subfloor down first. Plywood on rigid foam would do the trick. Or, you could go fancy and lay this down first:

http://www.dricore.com/en/eIndex.aspx

I've been told by experts here, that carpet is best for acoustics - unless you have lots of well-stuffed furniture and very heavy curtains. But, if you plan to include room treatments in the mix, you might get away with laminate, if that's your preference. I'm laying laminate - cause that's what I've been directed to do.

I'm not really sure what you mean by "false walls over top of the two cement/drywall walls". What is this false wall going to consist of? Is it a wall consisting of acoustic treatments? Or, is it for sound-proofing the room?

I'm sure you can incorporate acoustic treatment between studs in the wall. I'm no expert, but I don't think it would be a good idea to completely fill the wall with treatment though. You don't want a "dead" room any more than a highly reflective one.

If it's sound-proofing you interested in, try here:

http://www.soundproofingcompany.com/

I received a ton of valuable advise, even though I didn't end up incorporating any sound-proofing in my renovation. I can't wall off one end of my HT completely, so it's practically useless to try sound-proofing the rest of the room.

As for acoustic treatment, I'm sure bpape, or another expert will turn up to offer some educated advise. Be patient and don't rush this project. You're going to run into hiccups, so plan as far as you can. Then go through it all step-by-step in your mind and consider all the possible problems you could run into.

I started my reno a couple of weeks ago. I thought I'd be putting drywall back up by now. But, I'm still fixing the electrical wiring. That's where you have an advantage with an unfinished basement - you can see if there are problems. I only discovered my problems after tearing down the existing drywall.

Good luck!

 

[jostenmeat]

1) Should I build a sub floor to help my subs produce better bass? If so how thick do i need it to be and do I need to lay insulation under it?

2) Should I build false walls over top of the two cement/drywall walls or is the drywall already acting like a false wall?

3) I have accepted the fact I will need to remove the drywall from the rear wall to insulate it, but can I use 4" thick acoustic panel's to fill in between the 2x4 studs and not replace the drywall? (Maybe cover the rear wall with some sort of acoustically transparent fabric over acoustic panel's).

I hope you guys and gals can help me with this as I am sure to have more questions to come in the future.

Thanks.

1. Yes, cement will mean less tactile response. However, reducing height has its own inherent compromises too. It's way beyond me, but some people design their risers as Helmholtz resonators/traps. AH has an article, building your own riser, if you want to see it. However, on the large scale of a whole floor, I dunno.

2. This is a bit confusing to me too. One of the things that's nice about drywall is that it passes the very lowest frequencies (which are extremely difficult to trap otherwise), but OTOH perhaps it makes it easier to "pressurize" your room with the cement.

3. Insulation behind the drywall is not so much for acoustical performance, as it would be for acoustical insulation from the outside (say your child was sleeping on the other side or something). IF* this is the intent, the standard procedure for soundproofing is insulation between staggered studs, with double drywall (with green glue between the drywall layers).

However, I don't think this is what your intent is? If it is your intent, don't buy "acoustical panels" for this purpose, but insulation in bulk. If for acoustical in-room performance, this is where layouts/drawings and the help of b pape might come into play more.

Bang for buck treating is usually corner trapping first, as bass is normally the first issue. I've been told that you can't go overkill with corner trapping, but if you only do two corners, you'd want them to be at the front wall.

I believe the closer that you* or your speakers* are to any boundary, the more likely that boundary will benefit from treatments. For example, if you are close to back wall, that will likely benefit more from treating. If your speakers are close to the front wall, then the spots directly behind. If very close to sidewalls, then those first reflection points. Etc.