unfinished ceiling treatmen?

[RafaelM]

hello everyone, I've got a home studio that i'm still building in the basement.
specs:
- carpet on cement floor
- unfinished ceiling
- the walls- Cement-> fluffy fiberglass -> drywall
- the SOUTH Wall was built with plywood and drywall and insulation.
- 16 Feet wide, 11 feet long, 7 feet tall (if it is dry walled which i don't plan on doing). now it has U shaped holes and the holes are about 1 foot, so a total of 8 Feet. Right above is the floor above it.

I have a drawn picture attached to illustrate

anyways, i'm planning on putting a "cloud" to dampen the sound and affect the low frequencies. I have the Option of the Fluffy fiber glass, or Roxul Rockwool. Should I face that plastic towards the room or should i get a different material? I've hear that the reflective plastic will take away the purpose of the insulation, but Also heard that it can help to retain higher frequencies.

In addition I Do have 12 Bass traps (6 inches) to add to the room, and am going to make more acoustic panels (2 inch).
Any help would be appreciate it since I am an amature at this stuff still..

[avare]

You are making the total depth less than 8" so use the Roxul. At that height, pretty all reflections from the ceiling are too early to be pleasing, so plastic on the inside (away from the room). You may end up putting some reflective material on your bass absorbers to maintain life.

Good luck!

Andre

[Weasel9992]

Originally Posted by RafaelM

- 16 Feet wide, 11 feet long, 7 feet tall (if it is dry walled which i don't plan on doing). now it has U shaped holes and the holes are about 1 foot, so a total of 8 Feet.

Totally agree with Andre.

Agreeably,
Frank

[RafaelM]

Thanks Guys, just what I wanted to hear
so Andre, you are saying put Roxul and not the Fluffy Pink Stuff, and find a fabric just to cover it?
and for the bass traps...Ive done 10 that don't have any reflective surfaces on them, they are as shown in the picture attached here:

and I'm yet to do 2 more, just lazyness and busyness comes in.. lol
Would you recomend putting one of those wood panels with a bunch of little holes penetrating through it? like the ones that are used to hang construction tools. because the way I see it, it would reflect but it would also have air spaces so sound waves flow in the 4-5 inches of foam

[avare]

Originally Posted by RafaelM

Andre, you are saying put Roxul and not the Fluffy Pink Stuff, and find a fabric just to cover it?

Yes.

bass traps... would you recomend putting one of those wood panels with a bunch of little holes penetrating through it? like the ones that are used to hang construction tools. because the way I see it, it would reflect but it would also have air spaces so sound waves flow in the 4-5 inches of foam

I have not tried it, or seen anyone doing it, but acosutically it seems fine. Try it, and ley us know how it works.

Andre

[Weasel9992]

Originally Posted by RafaelM

Would you recomend putting one of those wood panels with a bunch of little holes penetrating through it? like the ones that are used to hang construction tools. because the way I see it, it would reflect but it would also have air spaces so sound waves flow in the 4-5 inches of foam

I used to work with one of the main R&D acousticians at JBL, and that's exactly what he recommended to me. I've never tried it either, but it does seem like it would work fine.

Frank

[avare]

This is not for Rafael, but for those who want in depth information on panels with holes in them.

The panels will reflect sound at wavelengths shorter than the length of the distance between the holes, and be absorptive below that frequency. With ~20% open area, the panels are acoustically transparent.

For an example of an absorber with such a panel see BBC RD 1982-08. For an in depth analysis and design criteria see Acoustic Uses for Perforated Metals: Principles and Applications by Theodore Schultz. The latter is a milestone in bringing the application of perforated materials for acoustics to the general world. Well, compared to pure academia and even more specialized acousticians.

Andre

[RafaelM]

thanks again guys, much appreciate it
It might not be soon, but I will post again on how well they do work...
I often see those kinds on panels in my Lecture Rooms in university on a diagonal slant from the actual brick walls...theyre these big 8ftx8ft panels and i'm guessing there is iinsulation in there to prevent the echoy/reverb. so ill try that, even though the room isnt the size of an Auditorium -.- (i wish)

[PaulP]

Originally Posted by avare

The panels will reflect sound at wavelengths shorter than the length of the distance between the holes, and be absorptive below that frequency. With ~20% open area, the panels are acoustically transparent.

I'd just like to point out that the hardboard with holes (pegboard) available in
building supply stores that Rafael mentioned is nowhere near 20% perforation.
I think it's more like 1% which would not be transparent.

The BBC document does say they used 20%. I wonder where they got it ?

Paul P

[Weasel9992]

Originally Posted by PaulP

I'd just like to point out that the hardboard with holes (pegboard) available in
building supply stores that Rafael mentioned is nowhere near 20% perforation.
I think it's more like 1% which would not be transparent.

Really? I'm looking at a piece right now and it sure looks like it could be close to 20%.

Frank

[avare]

Originally Posted by PaulP

I'd just like to point out that the hardboard with holes (pegboard) available in
building supply stores that Rafael mentioned is nowhere near 20% perforation.
I think it's more like 1% which would not be transparent.

Actually it is ~1.2%

The BBC document does say they used 20%. I wonder where they got it ?[/QUOTE]
From the manufacturer. It is made for them per their specification.

Well specified,
Andre

[Weasel9992]

Originally Posted by avare

Actually it is ~1.2%

Well specified,
Andre

Well...there you go then.

Spacially Challenged,
Frank