Posted by Rick Denney on August 20, 2000 at 19:00:03:
In Reply to: Kleenex and Spit posted by Rick Denney on August 17, 2000 at 11:49:25:
Okay, folks, I really do appreciate all the responses.
I believe my summary below was pretty close. Paul, with all due respect, I don't believe a trellis will have any effect, unless it cocoons the house and the hedge it holds is about four feet thick. And even then...
And, Mark, I think I understand the difference between an acoustic problem within the room and a transmission problem. I have not missed your good points. I don't want to absorb interior noises; I want to hear them. I do want to minimize transmission, but I might have used the term *absorb* to describe what a material must do to attenuate transmission. My objective with ceiling tiles (now abandoned) was to reflect rather than transmit. I'll be on the lookout for the books you mentioned.
I also talked with a fellow who designs radio station studios, and he is experienced with building "soundproof" enclosures. Total soundproofing is almost impossible, especially at these low frequencies. But it is possible to do two things: 1.) minimize or eliminate transmission of the upper harmonics, which should take some of the piercing qualities out of the sound, and 2.) reduce the magnitude of the sound to the point where it melts into the background noise and becomes unnoticable.
I've revised my plan for the basement build-out to include isolation. The walls will already be isolated by being separated from the basement walls by an air gap. They will not mechanically connect to the ceiling joists, but will stop about a half inch below them. I will build new ceiling joists, between the existing joists (which are really floor joists for the floor above, and resting on top of the false walls. There will be no connection between the interior false wall and the existing basement walls and ceiling. The existing wall to the stairwell will be widened with alternating studs to maintain the isolation. The stairwell will have a door at the bottom with an air-tight seal and a door at the top. The only openings to the outside from the basement are along the sides and back, and sound radiating in those directions is not the problem.
This will not eliminate the transmission, but if it takes even 20 db off the sound level, it will be unnoticeable.
Until then, I'll play when I feel like it, within reason (before 10 PM), and if my neighbor doesn't like it, he can ring my doorbell and tell me so. I'll also tell him that I've banished the tubas to the basement, so maybe that will program him (or should I say her?) not to listen for them.
If that isn't enough, then I'll tell them *they* have to move to the woods.
Rick "Or soundproof their bedroom" Denney