Help Building an Audio Room

Hi All

I have been allotted a 15x15 x 10h room in the corner of my basement by the wife.
While I’m very happy to have a dedicated audio room, I have some questions and concerns. I’m hoping you all might be able to help. 

1) Three of the walls are poured concrete.  The space has crazy slap eco already and the 4th/back wall is not even closed in yet.

I am having the walls framed in, insulated, electrical, drywall etc. I am thinking of having them frame and build one wall an additional distance off the cement wall some amount so the room is not a square

Is that a good idea?  If so, how much out of square does it need to be to benefit from not being 15x15? Is 15x14 enough? Should I go for 15x13?  I can set up the speakers about any way I would like. 

2) Next question.  Should I have them install a certain type of insulation behind the drywall?  Money is an object, but now is my chance to build the room the best way I can within reason and to offset the square room I’m starting with. 

3) Anything else I should consider before/as they begin to frame, etc? 

Thanks very much!


I have a second system in a 14’ x 13’ bonus room in my basement and I messed with it for several months and it is much better sounding, but still no where the same as the 15’6” x 20’ room upstairs. You need room behind your listening position that I just can’t get in that room unless I move the speakers closer to the wall and then the sound starts to suffer because the speakers are to close to the front wall.

All the best.

I would try to net out a 13X 15 X 9 room. Sound transmission to the master suite indicates using not only a resilient clip system for the ceiling, and a layer of 1/2" plus a layer of 5/8" sheetrock. Fill the joist cavities with rock wool. Make sure there is a 1/4" gap all the way around the ceiling that gets caulked with acoustical sealant. That creates a large, high mass diaphragmatic absorber that will minimize noise transmission upstairs. Also, any penetrations, e.g. lights need to be sealed as well.

For the framed wall, I have had great success with stagger stud construction - 2X4 studs staggered on a 2X6 plate. Use the same dual-layer sheetrock, resilient clips and 1/4" gap as the ceiling.

Have the electrician pull in at least one 20A (preferably 2) dedicated circuits and 2 quad boxes with medical-grade outlets (4-Leviton 8300 series ~$12 each) and add a whole house surge suppressor (your electrician will have a recommendation - budget ~$200 + labor). The total bill for that will be less than an aftermarket device and it will work better.

Carpet and pad are entirely up to you. I tend to favor a commercial grade carpet on a heavy pad to handle the intended traffic. 

Room treatment will make a huge difference. Budget for 6 or 8 2X4 ft 2" fiberglass panels, a couple bass traps and 9 2X2 ft 2" ceiling panels. Actual placement will vary depending on the final room layout . 

Below is my current home theatre / music room incorporating all the elements discussed. The in-wall JBLs, subs, matching surrounds and overheads required substantial active eq to get the sound I wanted, but due to the multi-use nature of the room, I didn't want to give up floor space for speakers. The piano key assemblage on the far wall is a combination absorber/diffuser and has worked very well. You can also see 3 of the 9 ceiling panels. I am very pleased with their performance as well. Bass traps are in the corners behind the seating. All gear except the projector and 110" screen is in a ventilated closet on the right.

The AV is powered by a Marantz 7015. An Adcom 555 powers the subs. I use an Amazon Echo Studio for background listening and to control lighting. 

Hope this gives you some ideas.



@jo1mtb Glad to read that you are finding the AMROC tool useful. The BOLT area calculation is pretty cool. Suggest that you also run the proposed room dimensions through Bob Gold’s tool before you finalize. It is more in-depth and provides a little more complete analysis.

Re: WAF and room treatment/bass absorption, I recently read about a clever idea that might work for you: build a full-width closet at one end of the room (maybe instead of the bookcases?) with louvered bi-fold doors and fill it with acoustic batting material. Sort of a large hidden bass trap. The louvered doors would allow bass waves to enter the chamber while acting as a primitive diffusor for the highs and the interior volume would be pretty large (2’ deep X 15’ wide x 10’ tall = 300 cubic feet), providing effective low frequency absorption and would be completely out of sight and relatively inexpensive compared to standard in-room absorption products.

@panzrwagn, I like your 'piano keys' approach on the wall.  A simple 'graphic' approach that makes what's usually bland into appropriate for a audio room....

I think I'll 'steal' that... ;)

Hi, Miller....I'm working towards a distributed sub system, think it'd best with my omnis...time will tell. *G*

Try contacting Matt Clott (spelling) from TAS.  His room is completely done up.  He may have some good suggestions for you and possibly some help in purchasing.


Happy Listening.