Will this perform as good as burlap ?

Jones_Rush · 10-02-2003, 08:35 AM

for an aesthetical covering for the absorbing panel:
Check out this.

I can get it for less than what the buralp costs in my country. But, if the burlap is better, I might go for it instead.

Chris Tsutsui · 10-02-2003, 01:10 PM

I bought some of that exact material from parts express, as well as having tried Burlap.

Keep in mind that the white grille cloth you posted isn't 100% opaque (means you can see the drivers behind the clothe a little).

Burlap has got to be as close to 100% acoustically transparent as I can imagine. I cannot tell what so ever when there is a burlap cloth in front of my speaker or not. That polyester cloth they sell at PE on the other hand, may be very transparent but probably not as transparent as burlap. I'll have to be honest, that I was unable to tell if the polyester was blocking any sound, but I suspect it was hiding some of the "sparkle".

That white polyester is practically flourescent, so be wary of how it will look. It also gets dirty fast with finger prints and stuff so keep your hands clean.

Parts express says that their cloth is "VIRTUALLY" 100% acoustically transparent which IMO is bad marketing and may mislead people. Burlap is better... it just may not look as nice.

http://www.angelfire.com/sports/RCcars/AV1.htm

Here is a link to what the cloth looks like on a pair of AV1s that were mounted in the ceiling of a bedroom I worked on. EVEN if I doubled up on the fabric, the black drivers were still visible.

Jones_Rush · 10-02-2003, 01:33 PM

Chris, so you say Burlap is better...
I'm going to use it with absorption panels, so I guess that means just the opposite for me. ie. the "sparkle" is going to *remain* in the room, which is a bad thing.

If only I knew a place to order it online... In America I saw that burlap is cheap, and it is also not heavy, so I could ship it. Only problem, where can I find it, and also, even I I'll find it, how can I be sure it's the right burlap ?, there must be dozens of versions... some might be less transperent than others... :-(

Edit:
I found this one. Is this as transparent as we need ?, can you even tell without testing it ?. At $63, it's a bit expensive though...

Pete Mazz · 10-02-2003, 03:01 PM

The grill cloth will be fine to cover absorbers. Why would you want something 100% transparent for an absorption panel anyway? As long as it's non reflective, like most soft fabric, you should try to get something that is more absorbant.

Either way, a millimeter or so of fabric is negligible to the amount of absorption in the rest of the foam behind it.

Pete

Jones_Rush · 10-02-2003, 03:36 PM

Pete,
What worries me about a cloth which is not 100% transperent, is that it will reflect (not absorb) the higher frequencies. Hence the overall feeling will be of a bright sound, in the room.

**HTF Ads**

TimForman · 10-02-2003, 04:22 PM

Leather furniture is not "transparent" but it dissapates sound waves.

Jones_Rush · 10-02-2003, 04:35 PM

Quote:

Leather furniture is not "transparent" but it dissapates sound waves

I'm looking for a bit more absorption accuracy than that.

Pete Mazz · 10-02-2003, 11:37 PM

With all the research you've done so far, you must now know that higher freqs are the easiest to absorb. Whatever fabric you cover the panels with will be fine.

Pete

Jones_Rush · 10-03-2003, 07:24 AM

Pete,
I really want to believe that what you say is true, since it will save me much money, but how can you explain the fact that those who built DIY absorption panels in the past, always took care that the outer cloth is not reflective (not absorptive!, if it is absorptive to higher frequencies then it is good)) to higher frequencies ?. Isn't this a fact, that tightly weaved fabrics will reflect high frequency sound ?.

Taken from Jon Risch website:

Quote:

....a fabric known as FR-701 panel fabric from Guilford of Maine. It is fire-rated, and acoustically transparent(for all practical purposes).

My experience has been that many fabrics that seem acoustically transparent may not be, and may cause significant reflections as the sound tries to enter the absorbing material. If ASC actually uses the stuff, it might be OK, but remember, many of their products are not designed for 100% absorption, but a controlled amount of reflectance.

Pete Mazz · 10-03-2003, 08:48 AM

Quote:

Isn't this a fact, that tightly weaved fabrics will reflect high frequency sound ?.

May be so. But your choices seem to be the PE grill cloth or burlap. I've used the PE cloth and it's a nice grill cloth. Either way, you're splitting hairs.

Besides all that, high freq sound isn't very hard to absorb. Most rooms with carpet and stuffed seating will do an admirable job. That's one reason why it's difficult to "correct" a room with absorbers. They almost always soak up too much of the top end while seemingly never enough of the low freqs. That's where bass panel traps come in. They reflect the higher freqs while absorbing the low bass (if you use enough of them in the right locations).

Pete

Jones_Rush · 10-03-2003, 09:06 AM

Pete,
This is why I've ordered 110 square feet of 6" polyurethane foam. Apart from this, I will be using a room correction software. The combination of both, I hope, will give me a more even decay throughout the spectrum. If not, then I would be able to say I've just made the most expensive error in my life, to date.

btw, thanks for all your help Pete. I appreciate it!.