Soundproofing a listening room

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Ive just been given the thumbs up from my wife to convert a large guest/junk room into a dedicated listening room. This room is below an office room that is attached to our master bedroom. I would like to soundproof the listening room by means of suspended walls and ceiling and a floating floor. There are several companies that sell rubber hangers that attach to metal channels that the drywall attaches to and then mounts to the studs and joists. There are lots of companies selling this approach. All of this is not cheap and alot of work. Is it worth the hassle?

Has anyone done this or have experienced, first hand, how well this works? Claims of 40 - 50db decreases seem pretty unbelievable but if they are accurate, that would be fantastic.
Recording studio guys might have a good idea of this method.

Any advise is welcomed.

amt
 
I've visited a studio that had this setup, and to appreciate the S/N (which was really good) you had to hold your breath. So unless you are going to do that while you are listening, it might just be an expensive overkill.

Apparently sheet lead in the walls absorbs sound well.
 
what I did years ago in my attic that had a usable 600 sq. ft. of space was lay down acoustic drywall and then applied a sub floor.
For the walls I built panels with dense foam covered with some material.It looked nice as I was lucky enough to find a print for the material that accented the room.

DIRT®
 
What is really effective is to build a “room in a room” That is to say build a sub-room where only the floor is resting on the floor of the building and the walls and ceiling are touching the main building nowhere. The floor of the sub room is resting on isolating rubbers. The walls and the ceiling can be made from a wooden framework and plated with plasterboard. The air space between the sub room and main building is filled loose with acoustical damping stuff.

Oh eh don’t forget to put an extra separate door in the sub room.

Not cheap but it is very effective and if you are handy yourself ...

Cheers ;)
 
Id thought about doing a padded panel thing but by the time I purchase materials, I can probably do a "room in a room". There cant be any overkill since this is actually to keep the audio noise out of the house rather than the house noise out of the listening room. My wife would rather not be woken up to Supertramp at two in the a.m. This is part of the deal.

Ive also come across ads for a rubber dampening material that is used between the drywall and the studs but the cost is so high, I could build an addition to my freestanding garage for that(which was the original plan until our remodeling budget exploded)

thx

amt
 
Home depot recently started carrying an excellent product called Sono Panel. These are 4 x 8 panels you put up on a frome under drywall. Just remember to use L channel on the studs to mount the drywall to.

If you do not want to strip the finished walls, I suggest buying the 2" rigid foam panels from Home Depot 2 x 8 sections. Enough to cover all your walls. Wrap them with Batting and then with a fabric, vinyl or leather of your choice. Do not cover the backside of the panels, but smother them in construction adhesive and press them on the walls. You will need to make cut outs for Windows, doors and electrical, but I think you get the idea. I am in the middle of doing a rom this way myself.

Regards

Anthony
 
How big is the room and what is your budget like?

To keep your family from being shaken out of bed you’re going to need to control the LF through mass and isolation.

The rubber material you’re talking about is likely a limp mass barrier. This stuff works by being very dense and impermeable. Every time I have looked at using this, acoustic lead (available pre laminated to drywall for x-ray shielding) or concrete block, I have come back to the same conclusion: sheet rock is cheaper. I’ve built rooms with up to 10 layers of sheet rock across an outer, middle and inner room frame, and doing all this framing with ½” sheet rock is still the most affordable construction technique.

Room in a room with a floating ceiling and floor will be requisite too. There just isn’t any other way of keeping everything below 100 HZ from exciting the floor and ceiling, making it audible throughout the rest of the house.

Now that you’ve made the room a lot smaller you should also be thinking about how to make it sound descent inside. By reframing for room within a room you can adjust the room geometry to minimize standing which also will help you with the LF response of the room. Likewise, getting a decent sound field through out the rest of the audible band is both art and science. You will want some surfaces not to reflect and others to reflect at least a little.

Door treatment is an art in itself, at minimum your going to need a well fitting solid core door with an automatic sweep and weather stripping, but that will barely get you 30 dB of attenuation.

http://www.zerointernational.com/education/acoustics/sb_frame.asp?page=7

Your heating vents will also make excellent wave guides delivering startling amounts of sound to other parts of the house.

If your really intent on 112dB without waking people at 2 AM, it can be done, but the engineering required wont be trivial.

Designs by an AIA architect with experience in this area can be surprisingly affordable.

Check out this site for a little information on a very high end listening room:

http://wsdg.com/portfolio/portfol.php?SL=ht&BL=2#

No, you don’t need to use an architect to get a decent sounding room that works for you, but working with someone who has truly been there and done that on all the details involved is invaluable.

(dont forget to tune the room to taste by strategicly placing a few dead cats here and there: http://www.diyaudio.com/forums/showthread.php?s=&threadid=23631)
 
I would like to ask for an opinion regarding this thread.

I am fortunate enough to have a separate room from the rest of the house neighbours, so no need to sound-proof it to the outside world.
How can i prepare it from the inside for good listening? rockwool, wallmate?
The room is built with concrete pilars and ceramic bricks.

Thank you
 
Claims of 40 - 50db decreases seem pretty unbelievable but if they are accurate, that would be fantastic.

This can be achieved with not that much difficulty, however that level of attenuation will only be achieved in the midrange. Hence 100db peaks there will go down to 50-60db. The same system that achieves 50db in the midrange, may only achieve 15db attenuation in the bass, hence you then have say 105db peaks which they will hear as 75db on the other side of the wall.

Drywall is usually the cheapest since it is made and manufactured in such abundance. It's most likely cheaper than purpose-designed "acoustic" drywall - often it's better to use two layers of regular drywall than a single layer of special stuff! Same with doors - can you get another door in there? Any kind of leak as well you must get rid of! HVAC ducts are a pest in particular, and if you can remove any ducts and replace with a different heating/cooling system it would help.

As I recall www.acoustics101.com is a very helpful site on studio design, much of which is applicable.

The basic principles are simple:

* prevent vibration from travelling through the envelope - hence room within a room
* as airtight as possible
* let the boundaries move - the enclosure should have high mass without being too rigid - hence the enclosure will tame room modes - a bomb shelter will most likely have terrible bass!

I would not in general recommend the use of an architect to advise on such a room, certainly not from an acoustic point of view. My training in architecture taught me about the basic physics and about concert halls, but nothing about hifi acoustics in small rooms. A diy audio enthusiast with a reasonable understanding of construction will most likely find a better method from a cost and performance point of view than a consultant.

There is a good book that I bought when I was thinking about building a dedicated HT room, see www.gedlee.com

I believe this guy has a PHD on small room acoustics, and you will find some good advice on the whole system, as well as tips on how to build a room within a room.
 
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