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Advice on dedicated room

Hi everyone ,

I am going to start building my dedicated listening room in the basement soon and need some input. My ceiling is just under 8’ so would 2x4s be adequate for strength or would 2x6 be better? Second , I read an article where Robert Harley was building a new room and used the ISO wall system from acoustic sciences and was wondering if anyone here has used it and liked it. I will at the least use 2 layers of drywall and green glue. Lastly my space available is 15’x16 1/2’. I know that is too square and I can shorten the 15’ direction if needed but if we’re to put a 45 degree angle on two corners ( one corner is needed for access to another area) would that negate the “too square” aspect? Thanks for your input 
ronboco
bkeske's avatar
bkeske
5,597 posts
 

It depends on the span of the 2x’s. I’m in the residential architectural design/build biz.


I assume you want to install a ceiling below the floor joists above and finish with 1/2” drywall. A ceiling without any storage load should be designed to support 15 LB per ft total load, (dead and live). Two layers of drywall will increase the span weight. Keep that in mind.


In general:


2x4 SPF #2 (standard stud grade lumber) can ‘free’ span about 10’-9” @ 16” o.c. (Single layer drywall).


2x6 SPF #2 can ‘free’ span about 16’-11” at 16” o.c.


Now, you can also secure the 2x ceiling joist to the floor joists above to help ‘reduce’ the overall span weight, but utilize the similar spans as above. In other words, if you want to span 20’ overall, then provide mid-span support from the floor joists above, making the effective span 10’.


Now, here is the deal, buying 2x4’s longer than plate stock, (14’ lengths), will not be easy to find, at all. Even good 2x6’s longer than 18’ will not be easy to find.


Feel free to contact me via message if you need more help.


rego
378 posts
 
What do you want to accomplish? Sound proofing or Acoustic Treatment? If both or either one you will need a plan and importantly some knowledge of how to set / realize the goal.
bkeske's avatar
bkeske
5,597 posts
 
I agree. Simply ‘throwing in’ insulation (blown-in cellulose may be better), or even ‘sound batt’, may not accomplish a goal for sound transmission or treatment. That is a science all to itself. Resilient channels, green glue, etc. are things often thrown out without any science backing up their use. And you may still need sound treatment on the drywall itself, regardless.

I'm not an expert in acoustical treatments, and a professional who is should be consulted if that is a goal in installing a suspended ceiling.
mike_in_nc
1,147 posts
 
Sound isolation ("soundproofing") is an entirely different thing from the internal acoustics of the room. In my experience building a room in our basement, they can work in opposite directions. The less leaky the room (to sound), the stronger will be bass nodes and peaks, and the greater the need for acoustic treatment.

When using two layers of sheetrock, I suggest using different thicknesses. Or you can use a commercial product like QuietRock, which has two different thicknesses with a resilient layer (like Green Glue) bonding them.

I worked with an acoustician who pointed out that any holes allow for sound transfer. So if that’s important in your room (it was here, to keep out HVAC noise), all electrical boxes need acoustical putty pads, edges of sheetrock should be sealed with acoustical caulk, and so on. You can find more info about construction practices on the QuietRock Web site. I also got a few things (door seals, mostly) and advice from The Soundproofing Company.

I used QuietRock rather than resilient channel because I couldn’t afford to lose the few inches of height that the latter takes. The finished room is just 7 ft high.

The hardest thing to reduce proved to be structure-borne LF vibration, such as the sound of a refrigerator above. But at night, the SPL A weighted is about 28 dB . . . very quiet!

When construction is done, you treat the room as you would any other audio room, with products from GIK, ASC, RPG, Vicoustic, or other acoustics vendors.

I hope that’s helpful and that it’s not TL;DR material.

ozzy62's avatar
ozzy62
3,130 posts
 

if you get nice earbuds from JVC that is better

What the hell does that even mean??
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