Make ceiling "disappear" with THINNEST absorbers possible?

[666666]

My ceiling is low... VERY low... we're talking barely 7 feet. It's all I have so I must make due. It CAN work if treated properly. It's a drum room so cymbal content is the biggest offender close to the ceiling.

Needless to say, I wish to make the ceiling sonically disappear. This means I need absorption that has zero reflectivity properties, especially in the upper-end.

The ceiling itself is dual 5/8" sheetrock, a 9" air gap filled with R-15 batt insulation and then a dual plywood floor above. I'm sure a certain amount of low-end will pass through the ceiling to the floor above, so in theory, I may not need to worry so much about trapping low-end at the ceiling. I will of course have good bass trapping inside the room itself at the corners, side walls to help with low-end in general, etc.

Since the ceiling is so low though, I of course wish to use the "thinnest" trapping on the ceiling as I could possibly ever get away with while still getting as close as possible to making the ceiling "disappear". I know, I can't have my cake and eat it too... but I'm gonna at least TRY

I know some high-end bass traps advertise that they actually reflect a bit of upper-end frequencies as to not make the room so dead and lifeless. In normal applications, this sounds like a great concept and I'm sure it works very well... and I plan to use such traps on the side walls.

But for the ceiling, I'm thinking I want ZERO reflectivity, especially at upper frequencies. AND... in a PERFECT world, I'd use a trapping material that is no thicker than 2 inches... ok, maybe I need to go to 3 inches... 4 inches would really be pushing it.. certainly cannot be thicker than 4".... but 2" - 3" preferred... otherwise I'll darn near be scraping my head.

Now, I'm not a fan of acoustical foam (like Auralex, etc), I generally do not like the response of this stuff, HOWEVER, I'm wondering if acoustical foam might be the best thing for my ceiling needs here. Foam will eat up ALL the upper-end and should in theory give me a totally dead response, even at just 2" or 3" thick. I do realize though that it will not perform well for ugly lower frequencies, but again, I am hoping that the ugly low stuff might just pass through the sheetrock to the floor above... it's not like the ceiling is made of 12" of concrete or anything.

Plus if I have GOOD bass trapping in the rest of the room (like RealTraps, GIK traps, etc), it will help eat up any extra low-end that might be bouncing around the room in general.

What do you guys think?

I know in general that most of the forum people here are anti-foam, and I understand why after having used it a few times.... BUT, I wonder if foam might be the ticket in this application.... key terms: thin as humanly possible, zero upper-end reflectivity, max upper-end absorption.

Here's a question... what would be better:

- 2" of SOLID acoustical foam (not wedges etc, but solid) - Note: 2" of SOLID acoustical foam can be achieved by taking two 2" thick wedge foam panels and mating them together, result is 2" thick foam with no wedges... for max performance with limited thickness

- 2" of rigid 703 or 705 (or professionally made traps made from such)

- Any other better options?

My understanding is that some 703 / 705 type traps will have some degree of reflectivity which is why I am thinking they will not be good here. Any upper-end reflectivity at ALL will make the low ceiling height sonically detectable on a recording.

Thanks

[Ethan Winer]

Originally Posted by 666666

I know some high-end bass traps advertise that they actually reflect a bit of upper-end frequencies as to not make the room so dead and lifeless.

Yes, but that's not what you want on the ceiling. 703 or 705 two inches thick is the minimum, and four inches thick is what you really want. Auralex foam is an okay substitute is if it's solid, not sculpted.

--Ethan

[guitarwes]

Even if you're 6' 4", you could still use a 4 inch trap with an air gap. Just don't jump! Plus, if it's gonna be a cloud over the drums, you'll be sitting anyways. I think the general consensus is to go for the 703, even 2 inches will be fine for a cloud. GIK advocates their 242 panels over the whole ceiling if I'm not mistaken. Hell, my fluffy 4-6inch 4'x6' cloud works great and still allows me to stand (I'm 5'10").

[Glenn Kuras]

Originally Posted by guitarwes

Even if you're 6' 4", you could still use a 4 inch trap with an air gap. Just don't jump! Plus, if it's gonna be a cloud over the drums, you'll be sitting anyways. I think the general consensus is to go for the 703, even 2 inches will be fine for a cloud. GIK advocates their 242 panels over the whole ceiling if I'm not mistaken. Hell, my fluffy 4-6inch 4'x6' cloud works great and still allows me to stand (I'm 5'10").

Yea if you space the panel 2" off the ceiling (our 242 has a 2" gap to the back) it will work just fine.

Glenn

[blarg]

I made some 4" traps with the 703 and they work great. I've got them stacked up as a vocal booth right now. They can be mounted to the ceiling by bungee cord for quick change of application.

In the drum/band room. Our ceilings are also pretty low. About 8ft with a few inches upward slant. So we pulled the sheetrock from the ceiling which allowed 8 inch tall 1 foot wide gaps from the supporting 2''x8'' beams. Still have cement floor (w/ rugs at least). We ended up putting only 2 of the 2" 703 2'x4' on the ceiling permanently and it made a huge difference. 1 over the kit, 1 over the center of the largest bare floor space. When I get around to it. were putting more up. Starting with the 4" over the kit. This stuff works great. Good Luck on your endeavors. snoogans.

[bitman]

I was under the impression that diffusion was how one could make a ceiling or wall "disappear". Am I wrong about that?

:Ron

[Ethan Winer]

Yes, absorption is more appropriate than diffusion on a ceiling. With absorption, sound that goes up never comes back, so that's like an infinitely high ceiling. With diffusion the sound does come back. The reflections are not as coherent as they'd be off a flat reflective ceiling. But sound is still reflected. The diffusor Demo video lets you see and hear the difference:

Diffusor demo

--Ethan

[Yetti]

Originally Posted by 666666

My ceiling is low... VERY low... we're talking barely 7 feet. It's all I have so I must make due. It CAN work if treated properly. It's a drum room so cymbal content is the biggest offender close to the ceiling.

Needless to say, I wish to make the ceiling sonically disappear. This means I need absorption that has zero reflectivity properties, especially in the upper-end.

The ceiling itself is dual 5/8" sheetrock, a 9" air gap filled with R-15 batt insulation and then a dual plywood floor above. I'm sure a certain amount of low-end will pass through the ceiling to the floor above, so in theory, I may not need to worry so much about trapping low-end at the ceiling. I will of course have good bass trapping inside the room itself at the corners, side walls to help with low-end in general, etc.

Since the ceiling is so low though, I of course wish to use the "thinnest" trapping on the ceiling as I could possibly ever get away with while still getting as close as possible to making the ceiling "disappear". I know, I can't have my cake and eat it too... but I'm gonna at least TRY

I know some high-end bass traps advertise that they actually reflect a bit of upper-end frequencies as to not make the room so dead and lifeless. In normal applications, this sounds like a great concept and I'm sure it works very well... and I plan to use such traps on the side walls.

But for the ceiling, I'm thinking I want ZERO reflectivity, especially at upper frequencies. AND... in a PERFECT world, I'd use a trapping material that is no thicker than 2 inches... ok, maybe I need to go to 3 inches... 4 inches would really be pushing it.. certainly cannot be thicker than 4".... but 2" - 3" preferred... otherwise I'll darn near be scraping my head.

Now, I'm not a fan of acoustical foam (like Auralex, etc), I generally do not like the response of this stuff, HOWEVER, I'm wondering if acoustical foam might be the best thing for my ceiling needs here. Foam will eat up ALL the upper-end and should in theory give me a totally dead response, even at just 2" or 3" thick. I do realize though that it will not perform well for ugly lower frequencies, but again, I am hoping that the ugly low stuff might just pass through the sheetrock to the floor above... it's not like the ceiling is made of 12" of concrete or anything.

Plus if I have GOOD bass trapping in the rest of the room (like RealTraps, GIK traps, etc), it will help eat up any extra low-end that might be bouncing around the room in general.

What do you guys think?

I know in general that most of the forum people here are anti-foam, and I understand why after having used it a few times.... BUT, I wonder if foam might be the ticket in this application.... key terms: thin as humanly possible, zero upper-end reflectivity, max upper-end absorption.

Here's a question... what would be better:

- 2" of SOLID acoustical foam (not wedges etc, but solid) - Note: 2" of SOLID acoustical foam can be achieved by taking two 2" thick wedge foam panels and mating them together, result is 2" thick foam with no wedges... for max performance with limited thickness

- 2" of rigid 703 or 705 (or professionally made traps made from such)

- Any other better options?

My understanding is that some 703 / 705 type traps will have some degree of reflectivity which is why I am thinking they will not be good here. Any upper-end reflectivity at ALL will make the low ceiling height sonically detectable on a recording.

Thanks

Alright....
I think you may be overthinking it Brotha.
Sure, you can get technical this, and technical that....but really, a combination of absorbsion and diffusion works fine.
I also have 7' cieling, so I treated the cieling in diffusor panels....I also used a combo of foam and diffusors on the surrounding walls.
Using cardiod condensors facing down at the kit for overheads, drum tracks sound great!
Good luck!!!

[TheRealRoach]

Originally Posted by Ethan Winer

*snip*
The diffusor Demo video lets you see and hear the difference:

Diffusor demo

--Ethan

Wow... I think the demo-order you chose was really interesting. I know the "untreated wall" sound well as I dealt with that a lot in my mobile stuff a few years ago. I've since set up a permanent studio in a dedicated spot and use mostly absorption. I'm pretty stunned by the realtrap sound especially given how close it is to the mic and performer....