John Sayers' Recording Studio Design Forum Archive

Hello,

I was reading in the Alton Everest book how ceiling tiles absorb quite a bit of low frequency energy. Has this been the experience of everyone else here?

At the moment, my live room has a very old drop ceiling in it. It's stained from years of smoke and just age. I'm debating if I should keep the drop ceiling or scrap it.

I intend to suspend Rockwool just under the ceiling as my floor (finished last night) is parquette hardwood with polyurethane sealer. Many people seam to agree that the live floor and completely dead ceiling are the way to go. This makes sense and reduces the parallel problem between the floor and ceiling.

The ceiling is about 9.5 feet tall, and the drop ceiling is about 18 inches lower. The Alton Everest book seamed to mention that the ceiling tiles didn't do much for absorbing high end. I find this rather odd, but I really can't argue with the guy. If this is the case, then I will definitely need to kill the high end with broadband absorbers (wrapped rockwool).

What do you guys think?

Brandon

PS You've heard be bitching and complaining about my live room for a while now. Just by adding hardwood and covering it in polyurethane, I can hear a tremendous difference. The room seams so much more alive without sounding like a cave. I guess I just needed a little more ambience.

Brandon,

> The ceiling is about 9.5 feet tall, and the drop ceiling is about 18 inches lower. <

Ceiling tiles can absorb bass to some degree, and a lot of this is due to the large space between them and the real ceiling above. But a panel half an inch thick is still only half an inch thick.

Here's what I'd do:

Replace ceiling the tiles you have now with inexpensive tiles that are based on rigid fiberglass. Home Depot sells them pretty cheap. Then lay fluffy fiberglass batts on top where they won't show. Batts six inches thick are okay, but those a full one foot thick are far better.

--Ethan

I purchased an excessive amount of Rockwool on purpose.

Would I get similar results with laying the 4" thick 4lb rockwool on top of the drop ceiling?

Basically, I'd like to minimize and further cash investment if possible. Considering, I already have the rockwool in supply, it would be easier just to use it... that is if you think it will be equally effective.

Brandon

Brandon

If it are standard absorptive (not too reflective) tiles, your solution is perfect.

Best regards
Eric

Okay, then that brings up another question.

Would there be much of a difference in acoustics from placing the rockwool above the drop ceiling or below it? Obviously, mounting the rockwool under the ceiling would be more difficult and time consuming (an issue), but I wonder if it have an significant acoustic benefit.

Brandon

One other thing,

Should I leave space in between the rockwool and the ceiling tiles or just slap the rockwool directly on top of the drop ceiling frame?

Brandon

Brandon,

> Would there be much of a difference in acoustics from placing the rockwool above the drop ceiling or below it? <

Yes, if you put it below - covered with fabric of course - you don't need to buy the thin Home Depot tiles I mentioned.

> Should I leave space in between the rockwool and the ceiling tiles or just slap the rockwool directly on top of the drop ceiling frame? <

The only distance that matters is the one between the rock wool and the rigid ceiling above. So just lay the rock wool in the grid, or on top of whatever tiles you end up using.

--Ethan

Let's say someone decided to go with the fabric covered rockwool ceiling option, how would you suspend it?

PT,

> Let's say someone decided to go with the fabric covered rockwool ceiling option, how would you suspend it? <

Brandon has a grid ceiling, so in that case mounting could be as simple as unrolling fabric across the top of the grid, and dropping the fiberglass panels into place on top of the fabric.

Attaching raw rigid fiberglass to the bottom of a sheet rock ceiling is more difficult, and requires some sort of mounting. I'm not much of a carpenter, so I'd probably just drive long screws through the hole mess and call it a day. But you need something to either drop the panels into, or some sort of long screw or nail, with a large diameter washer, to go through the panels.

--Ethan

So what's best, fabric and insulation, ceiling tile and insulation or drywall and insulation, assuming you leave an air gap between the insulation and the above floor sheathing?

PT,

> So what's best <

All that matters is the thickness and density of the fiberglass, and the size of the air gap to the rigid boundary above. Everything else is merely construction details that affect only appearance.

--Ethan

ok, so let's say my house is built with 2x8 floor joists, would i be ok to cover 2x4 pieces of 3 or 4 inch 703 and screw em right to the joists, with no drywall?

Thanks

Bryan Mills

Brian,

> my house is built with 2x8 floor joists <

In that case you can get good results, and for a lot less money and hassle, by simply packing the cavity with fluffy fiberglass. I suggest you get fiberglass 12 inches thick, and pack it in there tightly enough so it doesn't extend beyond the bottom of the joists.

--Ethan

I forgot a word on that last post

What i want to do is cover Roxul rht 40 with broad cloth and screw it up to be the ceiling. This needs to look nice becasue it's where my girlfriend and i will be living. Which would be much cheaper than insulation between the joists and drywall to finish it right?

Ethan Winer wrote:PT,

> So what's best <

All that matters is the thickness and density of the fiberglass, and the size of the air gap to the rigid boundary above. Everything else is merely construction details that affect only appearance.

--Ethan

Bryan

The first question is what's your goal???
Insulation .... Absorption.....
You compare entirely different things with different functionality.

So what matters is first defining a goal .....

Best .... for what?.....

Eric