Need Help Designing a Dream Room

Sean, Kelly, Albert -- thank you very much for your responses. You are most kind in taking the time to lay out your thoughts. Alexander (I assume), thank you for your comments as well and for reaffirming the suggestions that I seek professional help -- my wife has recommended that for years, but that's another story;-) I have heard that you don't want too much reflection or uneven (frequency wise) absorption but don't know enough about the properties of drywall to comment. A friend of mine once built a small sound studio surrounded by sand bags, but my wife would frown on that. Albert is correct that my only purpose is for stereo as my more modest surround sound system is in another room. I'll check out the options for home acoustics experts, but please keep the suggestions coming. Thanks.

There are no absolute rules in acoustic design. You can ask five different acoustic engineers the same question and get five different answers. On the surface this may appear confusing, but if you dig deeper, you'll find that each engineer has a design philosophy. Each element of the room and the reproduction equipment are designed to synergistically interact in in accordance with that design philosophy. You can get into trouble if you mix and match individual design elements from different engineers. If you decide to get professional acoustic engineering help, you will need to determine the engineers philosophy and make sure it's compatible with your goals.

The issue of surface rigidity is complex. In general, for home music reproduction rigid, but not overy rigid construction is best. Some wall flexibility can lessen standing wave problems. This will give you flexibility if in the future you switch to a different speaker with different low frequency tuning. In pro studios hyper-rigid wall construction is preferred. In a studio every element of the system is optimized to work together. The engineer knows exactly what speaker will be used, where it will be positioned and where the listner will sit. It's optimized, but it's somewhat inflexible.

Ozfly, there are two completely different issues being discussed. Reflection treatment and good building procedures. The two do effect each other, but flimsy construction is not the correct way to control overly dynamic or flashy musical reproduction.

Light weight construction allows various materials to move and vibrate, competing with your speakers. This not only effects bandwidth, but the solidity of the imaging and soundstage as well.

Secure, solid walls will reinforce bass frequencies rather than allowing them to "pass through" to other areas. If the bass is too much with good solid walls, bass traps are the proper cure, not transparent walls.

I plan on building my room as solid as possible, and then treat the interior walls with several acoustic materials. Below are two sites that provide some of the material I plan to use on the ceiling and the two long walls. This is in addition to RPG panels, Tube Traps and mechanical isolation devices.

If you consider that using the Whisper Walls treatment, you can avoid the expense of tape, bed, texture and paint. Removing the contractors expenses for these materials will offset the expense of this acoustic treatment. These materials are designed specifically to improve listening. Again, best of luck.

http://www.owenscorning.com/around/sound/acoustic.html

http://www.soundcontrol.com/whisper.htm

Lots of good advice here already, but as I quickly scanned it I didn't see anyone advising you to read books by F. Alton Everest, "Master Handbook of Acoustics" 4th edition, and especially "Sound Studio Construction on a Budget". The latter book has tons of useful sound treatment information and ideas for construction too. He and Robert Harley agree that nonparallel walls, while they achieve their goal, are not the only, or even the best, way to achieve that goal. Since the bad effects of parallel walls are quite easy to eliminate by inside wall treatment, I wouldn't contemplate that mode of construction, which I wouldn't trust many contractors to pull off. Good luck!

ozlfly: i quite agree with albert about the importance of a sound foundation (pun intended) before applying acoustic treatment. two of the best rooms i've listened in have quite different foundations. the first applied construction much as albert has suggested but uses dual stud walls; this system employs room-within-a-room construction with two 2x6 decoupled stud walls, each covered with double thicknesses of 5/8" drywall and each wall lined with acoustic dacron "insulation." a 2" air void between the walls adds to the sound isolation in both directions. the second "foundation" is comprised of brick laid inside two-foot thick stone exterior walls (not practical, agreed, unless you've bought a cottage in the cotswolds). check out the chord audio listening room (in kent, england--no, not the cotswolds) for an example of a "brick interior" sound room:

http://195.40.133.90/website/main-gallery.htm.

i particulaly like the way the ceiling is treated. don’t know how it sounds but it sure as hell looks great. again, have fun, you lucky..... :^} -kelly