Sound control when finnishing a basement?

Pbb's design IS very solid because it creates great density and to some degree "uncouples" the basement ceiling from the floor above. The biggest challenge in a basement scenario is (usually) very limited ceiling height - creating the need to balance out many de-coupling and insulating layers, with the need to keep 6 1/2 feet or so of usable room height.

Certainly professional guidance is always great. Two products that we have used somewhat successfully are "Fibrex" fiberglass insulating bats - probably the same product that Pbb was referring to - and also a product that's sold under the trade name "Sheet Block".

Sheet Block is an 1/8" thick roll of what's generically called Mass Vinyl. It has the density of lead at about 1/10th the weight. Although still heavy and must be put up carefully/safely - it really helps to preserve ceiling height while providing the isloation of around three layers of dry wall.

Sean - your suggestion about F. Alton Everett's book is an excellent one. I would also reccommend Jeff Cooper's book "Building a Recording Studio". While geared for bigger budget studio facilities, it has many tried-and-true ideas about un-coupling floors, walls and ceilings, plus step by step guidelines and cross-section views for isolation and even finished room treatments.

Pbb's response was/is an excellent one --should one have/decide on drywall finishing. Your dropped ceiling works like the resilient channels that Pbb spoke of; Use batt insulation (R-12) between the floor joists (along with the dropped ceiling tiles). This is the most economical and effective technique available. De-coupling, spacing and mass is the only way to acheive more effective acoustic isolation (between floors/rooms). Higher density/heavier ceiling tiles (the acoustic-type) is far better than the lighter variety. Although there is some contoversy regarding the density of the insulation (and its effect on sound absorbtion) I would suspect the denser type (Roxall or equivalent) would be the better/more effective insulation.
Bear in mind that duct-work or any other opening between adjacent floors/rooms is a conduit for noise to travel. Practically speaking, adding batt insulation along with denser ceiling tiles provides the best solution for minimizing noise transmission between floors.

peter jasz

There wasn't as much information available twenty years ago that's for sure. Some of this I got from a French language audio magazine which is no longer published called "Son Hi-Fi Magazine". They, in fact, published a brief review I had written of Allison:One speakers a long time ago. I liked the work Roy Allison had done on integrating the speaker as part of the room it was operating in. So very early on I was convinced of one thing: the very considerable effect (good or bad) the room has on the speakers. Some information I also got from "Audio" magazine which printed a brief series on designing and building LEDE listening rooms. Some of it came from the manufacturers of the wallboard and channels and from construction and renovation books and magazines. I may have gotten info from Stereophile or TAS, but I think the point was pretty well moot at that time since, if memory serves, the room was built by then. The ceiling height problem was solved by not installing any sub floor and by installing a foam backed carpet directly on the concrete floor. The front of the room is covered with inch thick natural cork tiles. The room did smell like an audio shop of years gone by for about ten years, you may recall the smoky smell of cork, I understand the dark brown colour is achieved by applying a flame to the material and, in fact, burning it. In the front part of the room, in a random pattern, the odd square of cork tile is found creating a double layer and acting, somewhat, as a diffuser. Another cheap trick I found is the use of foam spacers that are wavy, these are used in attics under Fiberglas bats too allow for air circulation. I covered these with white glue and affixed corduroy fabric to the whole thing. I have a couple of these on either side wall (my room is narrow at 12 feet) near the speakers and two on the ceiling a bit to the rear of and between the speakers. Another thing I found at Home Depot is carpeting that has a very corduroy-like pattern. I have squares of this placed on walls and on the floor, over the wall to wall carpet. Again, the main effect is to absorb, but I find that the texture also creates some diffusion. In the corners I used Sonotubes and gave them the same white glue and corduroy fabric treatment and stuffed them with Fiberglas. Two small Oriental rugs and one large one are hung on the walls in the front part of the room. Another Oriental carpet is on top of the wall to wall between the speakers and the couch. There is no furniture of any kind between the couch and the speakers. The equipment is now on a stand I made last year with an aquarium base made of very heavy tubular steel. The tubes have been filled with fast setting cement of the type used for fence posts. The top is Corian about fourteen inches wide and six feet long screwed to the base. This narrow base is installed along the front wall of the room. The two small windows are covered with curtains in a linen-type material. The rear wall of the room is covered with shelves holding books, knick knacks and artwork from my three kids. The one thing I never got around to doing is replacing the cheap luaun door with something more substantial that would be equipped with a foam or rubber gasket of some type to prevent the sound from going right through the gap around it. So that's it, most are twenty year old ideas and fixes for building a listening room on a limited budget. My last tweak (and believe me I am not into tweaking) is to tilt back my speakers using four hockey pucks under the front spikes. Very Canadian, no? The image height problem was solved. I hope I don't find or imagine any side-effects to this. That's about it. As you can see, I tend to substitute research and handy-work for the outlay of cash.

I would recommend something a little different. It's called a "chicago ceiling", and uses WHR blocks that suspend a ceiling that is then sheetrocked. You need the sheetrock to keep the sound in and controlled. As has been previously mentioned suspended ceilings won't do this. In fact, they stop very little transmitted sound and usually make the room sound terrible. The WHR block is a spring loaded suspension ceiling. This give virtually complete isolation to the floor above. Not only will you hear very little from the audio room, you will very little in the way of footsteps from above.

Thanks for all of the input on this issue. I like the ideas that use drywall/sheetrock but the reality of that approach is that you no longer have access to areas of the ceiling. This may be necessary in case of repairs and in some areas access on a regular basis is a must (shutoff valves for the lawn sprinkler system, gas line, and water lines). I will likely end up with some of the ceiling drywalled but a drop ceiling will have to be part of this process in some areas.