Home Theater Acoustic Panels

You can make your own sound-absorbing acoustic panels, but the tricky part is proper acoustic design for the whole room, including sound reflectors as well as absorbers. February 6, 2007

We've done several high-end home theater projects recently - this is truly an exploding niche. Our most recent customer spent over 1/2 million dollars (total) in just one room in his basement. While I can almost understand the exorbitant (opportunistic) pricing on electronics, seating, etc., I was amazed at the cost of the acoustic panels that were inset in our paneling.

Limited research has schooled me on things like "NRC" (noise reduction coefficient) and Class A fire retardant fabrics, etc. While many companies specialize in this field, and certainly many of you know more than I... It just looks too simple, so we've decided to fabricate our own this time. Does anyone have any experience with this?

Also, I'm looking for a local (Central NJ) source for Owens Corning 6 lb. density fiberglass panels.

Forum Responses
(Architectural Woodworking Forum)
From contributor K:
I'm guessing that the manufacturing of these certified/rated products is akin to fire doors. I've posted some questions regarding rated doors here, and yielded very little. For doors, there are considerable costs to earn your own "stamp." With doors, I can sometimes use a 2 5/8" thick door in an exterior jamb in lieu of a 20 min. fire door. Now it's only in a few localities that I can do this...

There may be some code considerations in making your own acoustic panels, and while a fire inspection may or may not be a factor, even if an inspector never even considers your panels during an inspection... We can assume the ramifications of violating a building code. I hope you take the initiative to look into this and post the results. I actually have a home theater install coming up this winter, and I would love to make rather than buy. Like you said, the costs are surprising - strike that, ridiculous - for custom acoustic products like you and I need. If you have the time to share what you've recently learned about "NRC" and fire retardant, please do.

From the original questioner:
Not quite the degree of scrutiny applied to acoustic panels as to fire rated doors. The whole room is wood paneled, so non-flammable fabric won't make much of a difference in a fire.

As to NRC, in a nutshell it's the amount of sound absorbed by the panels. The type of fabric wrapping the panels can affect the NRC. While all of the acoustic specialties companies offer materials with a better NRC, it seems that the 6 lb. density fibreglass panels I mentioned are very good, inexpensive, easy to work with, and readily available (though I haven't found my local source yet).

I just posted some pics in the project gallery, one of a theater. The panels were custom embroidered to a designer's specs. The customer opted to embroider every other panel, with plain black ones in between. The cost for 18 panels was over $30,000.00!

From contributor T:
I'm also in central NJ. We have used Armstrong Sound Soak panels in the home theaters we have done. My A/V guy used to own a cabinet shop, but now makes a lot more selling and installing theaters.

From contributor M:
Yeah, acoustic panels are simple to construct if you've got a little basic math and the right materials. You need the math to figure out what you need, why and where to put it. You may want to do a bit of online research into how to calculate room modes (if you aren't already familiar with this) to get a sense of how to thumbnail calculate where the frequency buildups and dropouts will be. Knowing that helps you select what kind of product to build. Knowing where to put it is a whole 'nother thing.

I've made my own acoustic panels, mostly for home recording studio applications (another technological explosion, one that started in the early '90's). Customers were literally bombarded with available foam products at the pro-audio retailers for years. It took until the late '90's for everyone to finally figure out that absorptive foam only gets you halfway there - you need reflection as well as absorption, plus accurate room measurement, to yield a good sounding room. I've walked into a few rooms that absorbed so much that it felt like I was walking into a head cold. One was more than halfway to becoming an anechoic chamber. Gee... and the customer wondered why the music sounded bad. So we had to add sidewall reflection panels and diffusers on the back walls in order to get the room sounding good again.

You might want to check out www.rpginc.com to see some additional designs/applications. They actually give you some cut sheet-able measurements with some of the products. I've been essentially one-offing their AbFlector design for customers and they work amazing for sidewalls between the speakers and the listening position.

In a home theater application, the aesthetics are admittedly a bit different than a home recording studio. But the principals are the same if you want good audio at the listening position.