Help me find the point of diminishing returns on my home theater soundproofing project! Plans and photos attached - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 9 Old 05-07-2013, 11:48 AM - Thread Starter
Member
 
PianoProdigy's Avatar
 
Join Date: Aug 2005
Posts: 53
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I have read most if not all of the content on soundproofingcompany.com and have learned a lot, but I still have a few questions about how far I should go with attempting to soundproof my theater from the rest of the house.

My new (to me, built in 2003) home has a finished walk-in attic that is currently being used a crude home theater above the garage that I want to finish and soundproof. I have attached floor plans of the first and second floor of the area as well as a couple of photos of the space as it is currently.

I have not yet been able to do any testing to determine the current state of the sound isolation from the rest of the house, but I imagine it is somewhat decent given the fact it is over the garage and on the opposite side of the home from the master bedroom. Still, just about any noise from the theater is going to be too much for my wife and newborn we are expecting in August (nursery is next to master on opposite side). I have 2 Epik Empire subwoofers as well as separately amplified tower speakers, so the system will be capable of some relatively-serious SPL. I realize that 100% noise reduction is probably not feasible, but I want to come as close as I can reasonably get. In other words, I am wondering what would it take to be listening at reference level in the theater and the rest of the house never know.

Obviously, I would prefer not to rip down all or most of the drywall to decouple, but if it is going to make a huge difference, I guess I will.

If that is not going to be a game-changer, I think I would plan on just adding a wall (I would guess staggered stud?) where I drew the red line with another solid core door with an automatic door seal at the bottom with 2 sheets of drywall on each side with green glue.

I think the next most important surface would be to soundproof the floor by adding mass. Would a layer of green glue over the existing plywood and then another sheet of plywood do the trick? Or should I also do a serenity mat first or something else?

What about sound flanking otherwise? Would it make sense to also do the walls and sloped ceiling where I marked in blue since that somewhat faces the rest of the house?

Thanks so much for your input in advance.

Second floor plans:



First floor plans:



Hallway and door into finished attic with sloped ceilings:



View of existing door and area where staggered stud wall to be constructed and door added as described above:



View of same area from opposite side:



View of location of screen and seating area with existing door at left:

PianoProdigy is offline  
Sponsored Links
Advertisement
 
post #2 of 9 Old 05-07-2013, 12:20 PM
AVS Special Member
 
jedimastergrant's Avatar
 
Join Date: Nov 2006
Location: Kansas City
Posts: 1,842
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked: 44
There is almost nothing you can do within reason to prevent low frequencies below say 30 Hz from escaping at least to some extent. So 100percent will not happen.

The best person to tell you where the point of diminishing returns is Ted White of thesoundproofingcompany. So I would suggest you just call him and ask for his opinion.

I hate to tell you but you will get almost nowhere without decoupling.

But even though you will never achieve total sound proofing especially at low frequencies it is not the end of the world. The LF may just sound like low level rumbling thunder in the kids rooms and with a fan going it may just do the trick. That is exactly what I am hoping to accomplish with my room.

To say nothing of the benefits of a low noise floor inside the room.

Good luck


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
jedimastergrant is offline  
post #3 of 9 Old 05-07-2013, 12:38 PM - Thread Starter
Member
 
PianoProdigy's Avatar
 
Join Date: Aug 2005
Posts: 53
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I sent 2 detailed emails to soundproofingcompany similar to what I posted in this thread but did not receive any response. I have not actually called yet.

If decoupling is necessary, I will do it. I guess I'm just trying to get an idea how important it is to the process to accomplish, or get as close as possible to, my goals.

I imagine the short answer is, "what you proposed would help, but adding decoupling would make a huge difference and would be worthwhile." Just trying to get confirmation of that.

The worst thing would be to spend a bunch of time only to be thoroughly let down by the results.
PianoProdigy is offline  
post #4 of 9 Old 05-07-2013, 02:33 PM
AVS Special Member
 
jedimastergrant's Avatar
 
Join Date: Nov 2006
Location: Kansas City
Posts: 1,842
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked: 44
Yes you are correct. Decoupling is essentially the most important step in soundproofing and there would be a drastically reduced effectiveness without decoupling. So much so that Ted recommended I basically do next to nothing regarding soundproofing if I was planning to leave the existing drywall in place. That said, every situation is different and the best thing to do is just call him and find out. It does little good for me to even say anything else since it will all be cleared up after the call much better than I could ever hope to.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
jedimastergrant is offline  
post #5 of 9 Old 05-09-2013, 04:44 AM - Thread Starter
Member
 
PianoProdigy's Avatar
 
Join Date: Aug 2005
Posts: 53
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by jedimastergrant View Post

Yes you are correct. Decoupling is essentially the most important step in soundproofing and there would be a drastically reduced effectiveness without decoupling. So much so that Ted recommended I basically do next to nothing regarding soundproofing if I was planning to leave the existing drywall in place. That said, every situation is different and the best thing to do is just call him and find out. It does little good for me to even say anything else since it will all be cleared up after the call much better than I could ever hope to.

I guess I am resistant to the idea of decoupling because it seems to me (as someone who has obviously never done drywall work) that it would be a pain in the ass with all the angles in the room since it has the sloped ceiling. Obviously, a rectangle with 6 sides would be more straightforward, but maybe I am unnecessarily worried about the complexity, and the average contractor would find it to be straightforward.
PianoProdigy is offline  
post #6 of 9 Old 05-09-2013, 02:15 PM
Advanced Member
 
dwightp's Avatar
 
Join Date: Sep 2007
Location: Mesa, AZ
Posts: 630
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 12
Quote:
Originally Posted by PianoProdigy View Post

I guess I am resistant to the idea of decoupling because it seems to me (as someone who has obviously never done drywall work) that it would be a pain in the ass with all the angles in the room since it has the sloped ceiling. Obviously, a rectangle with 6 sides would be more straightforward, but maybe I am unnecessarily worried about the complexity, and the average contractor would find it to be straightforward.

There is a great deal of tension between your desire to listen at reference levels without disturbing a newborn, and your desire to avoid a lot of work that amounts to a pain in the ass. You can have good sound control, or you can have easy. It's not realistic to think that you can have both (unless you can pay to have competent professionals do it for you).

Maker of the finest saw dust since 1980, give or take


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
dwightp is offline  
post #7 of 9 Old 05-09-2013, 02:23 PM - Thread Starter
Member
 
PianoProdigy's Avatar
 
Join Date: Aug 2005
Posts: 53
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Fair enough. I have contractors to do the work, and I am not cheap, so I don't mind spending the money to do it right. I just want to make sure it is, in fact, done right. That's all.
PianoProdigy is offline  
post #8 of 9 Old 05-14-2013, 10:48 AM
AVS Special Member
 
Ted White's Avatar
 
Join Date: May 1999
Location: Midland, MI USA
Posts: 8,186
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 32
If you don't decouple, you won't have much LF isolation as others have described.

__________________

Ted



The Soundproofing Company
Ted White is offline  
post #9 of 9 Old 05-14-2013, 09:28 PM
AVS Club Gold
 
warrenP's Avatar
 
Join Date: Jul 2005
Location: Now in Colorado!
Posts: 1,800
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 53
Quote:
Originally Posted by Ted White View Post

If you don't decouple, you won't have much LF isolation as others have described.

The above is your answer. Decoupling is a critical element in your overall soundproofing plan. Yes the angles will be a pain, no doubt about that. But if you are trying to have any sort of effective sound isolation, you need to address decoupling. It is one of those 'have to do it' parts of wanting sound isolation.

I'd spend some time to see what sort of framing change(s) you could make as well. For example, there is that beam shown just inside the doors. I would frame that straight back, getting rid of the raised ceiling there. That way you are not trying to box around and decouple around that beam. "Small" changes like that can help to make the overall project a bit more simple.

Every man dies. Not every man really lives.
warrenP is offline  
Reply Dedicated Theater Design & Construction

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off