Axiom Home Page Forums General Discussion Technical Questions What is best way to soundproof a room and cheapest

Ok. Obviously I have a basement that I am going to create a theater room out of. The thing I don't want to have happen is my girlfriend telling me every five minute to turn it down. This situation makes no one happy. I want to be able to watch my movies like I am at the theater, but at the same time I don't want to blow out my girlfriend upstairs. I have been doing some research on it and there seem to be many different products, but I am not a Sound Guru and I need some advice. Ian, HELP!!! or if anyone else knows of ways to do this. I ultimately want everyone to be happy. Are there any low cost ways I can build it. I would like to do it myself without a contractor. The room is a concrete basement floor with no walls. I am going to build the studing myself with my dad. So I really have a lot of options. Anyone out there know the best way to do this? Thanks

"Cheap" is relative.

It also depends on what the maximum SPL you will want to achieve. If anyone has actually measured a good theater to provide a reference listening level that would be a start.

You have many options for construction to give you varying STCs.

The quick and cheap would be to build your stud walls and line with Roxul Safe 'N Sound finishing with two layers of drywall. You will also want to line the joist space with the same insulation. Seal all wall-floor interfaces with acoustic caulking ( a heavy bead under the floor plate will suffice.

Be sure to provide adequate insulation around the ductwork, as applicable to reduce unwanted vibrations from the subwoofer.

If you drywall your ceiling, leave a 1/4" space between the wall and ceiling to seal with acoustic caulking. Otherwise if you use T-Bar you may be alright.

It is VERY important to use an exterior grade door to the home theater room. In addition to this, use a self-closing weather-stripping device on the bottom of the door and weather stripping around the door. You need to block the energy from the room from escaping.

If you know your basement floor has no cracks or leaks, etc. you can purchase a carpet with a backing suitable for that application, otherwise you may need a product like Delta-FL with a minimum 1/4" subflooring over top.

I don't know what Roxul Safe N sound is? Are we talking regular insulation or is there something reasonable out there that would help the STC rating. With this system you are talking about. What total Stc reduction are we going to get with this configuration. Thankyou for helping me. I really appreciate it.

Hi Jhunt17,

You have to use staggered studs as well so the interior drywall won't conduct vibration and sound through the framing to the remaining structure of the house.

Look in the archives of Sound&Vision magazine on-line (soundandvisionmag.com). I know there are past articles that have appeared there with detailed instructions on staggered stud construction.

If it's forced air heating, there are baffles you can install in the ductwork to keep that from acting as a conduit for sound.

Also search some of the white papers written by my old mentor, Dr. Floyd Toole, on the harman web site. I think he has addressed this subject. He wrote columns about it for me when I was a magazine editor.

Regards,

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I don't know what Roxul Safe N sound is? Are we talking regular insulation or is there something reasonable out there that would help the STC rating. With this system you are talking about. What total Stc reduction are we going to get with this configuration. Thankyou for helping me. I really appreciate it.

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Sorry about that. http://www.roxul.com/sw34143.asp

or the Canadian site that I reference http://www.roxul.com/sw47802.asp

As far as wall constructions go...

http://www.quietsolution.com/Construction_Solutions/construction_solutions.html

This is one of the best resouces I have seen. Alan is absolutely correct that staggered stud will achieve a much better result and then the extreme is double wall construction. Every step up gets a little more expensive in its construction. You have to determine just how much "noise" your girlfriend can tolerate.

Everything must be sealed for the ideal performance. If you had a subwoofer and drilled a 1/8" hole in the enclosure you would destroy the acoustic properties of the sub and seriously degrade its performance. The same can be said about a leaky home theater room.

Doesn't taping the joints provide a seal? I'm not understanding the need for the 1/4" gap and cauking. Can you explain that?

We recently renovated our new basement and the media room is almost complete. With a size of about 18' x 16' with one angled wall, our space was restricted for such options like staggered studs or double wall construction. The staggered studs require a 2x6 base with 2x4 studs and doing this along all 4 walls meant a reduction in space where inches make a difference between function and slightly less function (e.g. door relocations b/c a wall opening needed an extra 2-4" to fit, slightly shallow headroom on the angled wall b/c of the lost inches in distance from the wider build, etc.).
If we had a bit more space, i would have constructed a design for the walls in this fashion. Compared to a double walled room, it is cheaper.

However, with a good quality wall batting for sound insulation, you can achieve excellent results in sound reduction into other rooms. This material can be found any any Home Depot or Rona store. Drywall the ceiling (drop ceilings had a large tendency to rattle something nasty) and put acoustic batting between all floor joists as well.
Before any walls are sealed in with drywall, give then a good shake and see if anything is loose. Tighten up the shaky walls and build them solid.

Yes, a door is an absolute must for the media room, but an external door is not 100% necessary. Any 'solid' door will do. The hollow core doors commonly used for interiors are useless in this capacity, but you can buy reasonably priced solid wood doors that are very effective. Adding the weather stripping and door sweeps will help to contain air pressure and sound energy.

Lastly, i recommend putting in a good plush carpet with some beefy furniture pieces.
With our system at about 80% in that room, the sound in the next door games room and in the upstairs family room immediately above the media room, sound levels are well within easy tolerances for having conversations.
When i get around to it, i will post pictures of our latest and massive venture along with some numbers of SPL inside the media room and then around the adjacent areas.

If you are looking for dead silence or close to it outside of this area, some more serious design ideas will need to be followed.

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Doesn't taping the joints provide a seal? I'm not understanding the need for the 1/4" gap and cauking. Can you explain that?

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Yes taping it will seal it. If you can guarantee that your home will have 0% shifting (which is next to impossible here in Winnipeg unless your home is built on piles), then taping should be ok for a seal. However, sound energy can be transmitted through drywall tape versus acoustic caulking.

When I use 1/4" as an example for the spacing, it trys to take into account any shifting of walls, etc. The acoustic caulking remains flexible and will move with the wall/ceiling joint.

What I'd recommend is acoustic caulking to seal and then finish with drywall tape. Acoustic caulking is very inexpensive.

As pointed out by Cheseroo, you do not need an exterior door. It is correct that it need only be a solid door. I may be incorrect but the exterior doors are usually a little thicker and that greater mass would provide greater isolation.

Thanks for all of the help I am getting. I am really enjoying learning about all of this. I just hope I am able to build the room correctly and well enough to listen to movies such as The lord of the rings star wars ect. at levels I will enjoy and not irritate anyone else in the house. I have been reading about something called quiet rock that is like regular sheetrock, but is supposed to do a good job. Has anyone heard of this or used it? Also what materials will give me the stc rating in my room that I want? Am I shooting for an stc rating of 50 or 60? This room is going to be in a basement with concrete walls. The walls that are next to the concrete, do I still need to stager my studs in the room here? As I learn more, I find more questions to ask. Anyway, thank you everyone for your posts.

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Am I shooting for an stc rating of 50 or 60? This room is going to be in a basement with concrete walls. The walls that are next to the concrete, do I still need to stager my studs in the room here? As I learn more, I find more questions to ask. Anyway, thank you everyone for your posts.

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I am still waiting for a local supplier to get Quietrock in stock. Until then I may end up building with regular sheetrock .

The walls with basement need only be standard insulated stud construction.

If you are trying to figure out ideal dimensions, there are programs available that allow you to input dimensions of the room and the listening position and they will calculate theoretical nulls and peaks. Programs like these allow you to play with the dimensions to get the "best possible sound" from your room. Bottom line is that being able to construct a dedicated room to home theater will yield results far superior to simply plunking speakers throughout a space wherever the wife will allow .

As far as the STC rating, all I can say is to aim for the most you can afford. It is similar to investing more money into speakers. You can not underestimate the importance of a well constructed listening room. Some people will argue that a listening room should be the second biggest investment next to speakers.