Fiberglass ceiling tile for bass trap?

Xi-Trum · « **on:** 7 Feb 2005, 04:06 pm »

I was "strolling" around HD and saw that they have 2x4 fiberglass ceiling tiles ($2.21/sheet). They're practically rigid fiberglass with some sort of textured foil facing on one side. They are only 5/8" thick, though. But I figure stacking a few on them would solve the thickness problem.

Anyway, would this be a good material for building a bass trap panel? If so, how thick should I stack them? And should the textured facing be removed? Thanks a bunch.

woodsyi · « **Reply #1 on:** 7 Feb 2005, 04:18 pm »

If they are drop ceiling tiles, they don't do much for bass. I was told by Ethan that stuffign 12" (RU38) fiberglass insulation above the tiles at thecorners and walls would improve bass. 80 sq. ft cost $36.00 at Home Depot. I have done this along with putting up some traps. The bass is now tight.

Xi-Trum · « **Reply #2 on:** 7 Feb 2005, 04:59 pm »

Thanks. I'm confused, though. These ceiling tiles are made of fiberglass (not the hard solid ceiling tiles). In fact, they look (and feel) exactly like rigid fiberglass. So, they should exhibit the same absorption characteristic as rigid fiberglass. The box even mentions "acoustical". They're not as thick but they're pretty dense.

I'm asking since I don't see anyone talking about using these.

woodsyi · « **Reply #3 on:** 7 Feb 2005, 05:13 pm »

Even for compressed "rigid" board, I think the magic number is 4" for bass. 6 of those tiles won't be much of a bargain over 12" uncompressed insulation bat. But may be they are good for higher frequency absorbsion which would be good for 1st reflection point on the ceiling.

JoshK · « **Reply #4 on:** 7 Feb 2005, 05:29 pm »

Csero uses these glue together for room treatments and he did so with good looking treatments and very effective.

csero · « **Reply #5 on:** 7 Feb 2005, 06:21 pm »

I'm using them for mid-hf only. For LF I have an almost perfect golden ratio room with 6 speakers pushing the bass from different locations.

Frank

JLM · « **Reply #6 on:** 8 Feb 2005, 12:39 am »

BTW ceiling pads are generally made of three substrates:

cheap: medium density fiberglass (flexible and obviously fiberous, vinyl faced)

medium priced: mineral wool (breakable and somewhat powdery when broken)

commercial applications: gypsum (heavy caulky drywall)

Ethan Winer · « **Reply #7 on:** 8 Feb 2005, 04:13 pm »

Xi,

> They're practically rigid fiberglass with some sort of textured foil facing on one side. They are only 5/8" thick, though. <

Woodsyi has the right answer. However, just to be clear, those tiles are indeed rigid fiberglass. So you could layer them to be 3-4 inches thick and get the equivalent of that much rigid fiberglass. But you'd need to peel off all the plastic surfaces except the bottom one that faces into the room.

--Ethan

tkp · « **Reply #8 on:** 8 Feb 2005, 07:44 pm »

Since Xi is asking about rigid fiber glass, I am going to toss in my question about its use. How do I build corner bass trap using rigid fiber glass sheet?

I read about John Risch cylinder corner bass trap but I don't want to build any thing out of batting fiber.

Thanks,
TKP

Ethan Winer · « **Reply #9 on:** 9 Feb 2005, 03:50 pm »

TK,

> How do I build corner bass trap using rigid fiber glass sheet? <

It's all in the Acoustics FAQ, second in the list on my Articles page:

www.ethanwiner.com/articles.html

--Ethan