Ceiling Mounted Bass Trap from RC-1

[dtess]

I've looked for the answer to these questions but I can't seem to locate them, so sorry if this has been covered.
Can you attach panel traps to a ceiling of 2 layers of 5/8 rock attached to resilient channel? Or even attach bass traps of any kind to a wall or ceiling with Sheetrock attached to resilient channel? If so, what is the best way? Ethan I recall something about toggle bolts. Can the holes from the toggle bolts compromise the STC of the wall? Will the weight of the trap cause a negative effect on the RC?

Thanks,
Dave

[Ethan Winer]

Dave,

> Can the holes from the toggle bolts compromise the STC of the wall? Will the weight of the trap cause a negative effect on the RC? <

Those are excellent questions. Unfortunately, I'm not qualified to answer either of them.

Hopefully someone else more experienced with RC will chime in. I assume there may be better devices than toggle bolts for attaching things to the ceiling without compromising isolation.

--Ethan

[dtess]

Ethan,

Thanks for the response.
If you were to fabricate a panel trap on a wall or ceiling with RC how would you do it? Would you do it? I know my control and live room will need some sort of treatment and I don't want to make life more difficult down the road when the traps are installed. I plan on using the ceiling as real estate for bass traps, if it is not a good idea to do this I need to re-think my design. Anybody? Here's a link to the room layout.
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=901


Thanks,
Dave

[knightfly]

Dave, most RC manufacturers don't recommend more than two layers on their RC for ceilings - and acoustically, traps don't belong on resilient surfaces - if you can put RC on only one side, and the traps on the other, then the only drawback is the STC hit you will take when putting ANY holes in a sound wall. Probably the least obtrusive thing would be to mount the traps through the drywall and into the STUDS, and only from the non-RC side.

Also, isolation will suffer a small amount wherever traps are located against walls - it's the TANSTAAFL principle, anything you "trap" that doesn't get back into the room, has to go somewhere... best way to handle this is an extra layer of mass in one of the leaves of your 2-leaf wall to compensate for the slight weakening caused by the trap.

Speaking of ceilings, what did you decide on? can you post a pic showing what you've done with your flimsy roof framing and how you're planning on doing your ceilings now? (man, the other thread ran dry back in November of last year, had to do a "refresher course" to remember what we were discussing back then... ) Steve

[dtess]

Steve,

Yeah that was a ways back. Had an engineer come in look at it, first he laughed and then told me to string 2x8 rafters all the way across the span resting on the top plate on 24" centers. I have some other qustions and I will post them on the original thread. Just getting started and hoping not to make a wrong move that cost too much money or time. Again thanks for the help. I'll get some thoughts lined up and post in a couple days.

Thnaks,
Dave

[Ethan Winer]

Dave,

> If you were to fabricate a panel trap on a wall or ceiling with RC <

For a room that size I suggest you use thick, dense, rigid fiberglass panels as bass traps, and put them across as many corners as you can manage. Not only is this much easier to do, and less work and less expensive, in a room that size it will probably work every bit as well.

--Ethan

[dtess]

Thanks Ethan

Dave