Some Advice on DIY Bass Traps

[Loren Littlejohn]

So we are talking a larger R value that comes in sheets then.

Okay.

Thanks for the info!

[Ready Acoustics]

Originally Posted by HexTheNet

If you can get OC705 (without the kraft facing), then get that. It works a lot better for the lower bass frequencies in the room which is a typical problem of home studio set ups and still does as good as a job on other frequencies as OC703. As far as I know, it dosen't come in a roll, it's rigid fiberglass and comes in 4ft X 2 ft either 2'' or 4'' deep, 4'' being better for bass traps.

I gotta disagree with you on this. (nothing personal).
I've tested both products, and Owens Corning's own coefficients tables show that 703 is better at controlling lower frequency modal issues. We use a semi truck full of Owens Corning 703 on a frequent basis and have tried nearly every product you can think of. Higher density materials such as 705 are not better at absorbing low frequencies, as the thicker you go with your absorption panels/ installation, the less dense your materials should be.

Here are the absorption coefficients as shown on the Owens Corning website, and reprinted at Bob Gold's website in their original form:

http://bobgolds.com/AbsorptionCoefficients.htm


Look at the table for 4" thickness 705 and 703. 703 measures 1.24 (at 250hz) whereas 705 measures at 1.19 in the same frequency band. 703 costs a lot less than 705 and weighs half as much. It's a great product and I recommend it all day, every day to my customers. 705 is not a "bad" product, it's just not as good a product as 703 if you are looking at the acoustical lab data and if you consider practical use and cost.


I hope this information helps?



~ Joel
www.readyacoustics.com

[Ready Acoustics]

Originally Posted by GuitarGodgt

So we are talking a larger R value that comes in sheets then.

Okay.

Thanks for the info!

Don't look at R value unless your only concern is heat transfer and sound (energy transfer) between rooms. To control modal issues in your room, to focus your mix and to finally make your low end (in your mix) translate well, you need to consider Sabins and Coefficients.


Check out this site:

Bass Traps Network (I moderate there)

...and this site:

http://forum.studiotips.com (this site is moderated by acousticians (real ones) and is frequented by acoustical engineers, acoustic physicists and all sorts of people who do this for a living.



~ Joel
ReadyAcoustics.com
www.myspace.com/powermadband

[AStacy2]

Originally Posted by Ready Acoustics

I gotta disagree with you on this. (nothing personal).
I've tested both products, and Owens Corning's own coefficients tables show that 703 is better at controlling lower frequency modal issues. We use a semi truck full of Owens Corning 703 on a frequent basis and have tried nearly every product you can think of. Higher density materials such as 705 are not better at absorbing low frequencies, as the thicker you go with your absorption panels/ installation, the less dense your materials should be.

Here are the absorption coefficients as shown on the Owens Corning website, and reprinted at Bob Gold's website in their original form:

http://bobgolds.com/AbsorptionCoefficients.htm


Look at the table for 4" thickness 705 and 703. 703 measures 1.24 (at 250hz) whereas 705 measures at 1.19 in the same frequency band. 703 costs a lot less than 705 and weighs half as much. It's a great product and I recommend it all day, every day to my customers. 705 is not a "bad" product, it's just not as good a product as 703 if you are looking at the acoustical lab data and if you consider practical use and cost.


I hope this information helps?



~ Joel
www.readyacoustics.com

Thanks Joel, I didn't check any of the info you posted out though because I think you are mistaken. Maybe you can check this website out but it seems like OC705 is the clear winner at 42hz, the deep bass frequencies that lots of smaller project studios have problems with?

http://www.ethanwiner.com/density.html

[Ready Acoustics]

The problem with this "report" is that is was not conducted in a Reverb Chamber where it can only be measured correctly. Taking measurements in an unfinished room, with an inexpensive mic and a piece of software is not conclusive.

Check the data from Owen's Corning's own acoustical analysis. OC had a serious, vested interest in the making of 705 as an acoustical absorber. They spent many hundreds of thousands of dollars refining the product only to conclude publicly that is did not do what they intended. The cost of 705 is proof enough that they spent the money, and the company's OWN findings show that 703 (instead) is a better acoustical absorption medium. Indeed there is NO reverb chamber in the USA or Canada or anywhere else in the world that can measure absorption coefficients (with much certainty) below 80 or 100 hz because the rooms are not big enough to produce such a very, very long wave. When you get to 60hz and more so at 45hz, the "percentage uncertainty" in the accuracy of such tests increases to some 400%. That is 400% uncertainty that test is correct, and this is when products are measured in a state-of-the-art, acoustical chamber founded by and built by Dr. Sabin himself. The dirty secret with most acoustical tests conducted by acoustical panel manufacturers, is that they don't publish the full report and more importantly, the percentage uncertainty about the accuracy of their tests at 80hz and below.

Now, juxtapose that information with taking a couple of measurements in an unfinished room, with a cheap mic and yet another version of a piece of software a.k.a. "home testing". That my friend, is not data I would ever hang my hat on. And again, why would anyone, for any reason argue the test results and findings of Owens Corning's own published report? They had every reason in the world to build 705 up so they could justify the dramatic cost difference. OC couldn't even justify lying about the effectiveness of both products because they are a world-class, reputable company who would have been thrown to the lions if they did. Instead, they told the truth, and consumers win.

Ask real acousticians what is a better absorber, they will tell you to look at data and then use your ears.

We tried to make OC705 work better than 703, and even with tens of thousands of dollars invested in acoustical lab testing, we could not. So again, who wins? The consumer.

703 is a better acoustical absorber than 705 at all frequencies, check the data from OC, and other Acoustical Lab testing. And remember, "percentage uncertainty". Acoustical products companies absolutely will not publish this in their testing reports so that you stay "in the dark". We did, and you can see it at our Acoustical Data page, if interested. Do check the OC data as well, it is an eye opener.

Thanks for this thread. It's enjoyable speaking with folks who demand truth, and I hope some of this information helps us get to that end.


Cheers!


Joel
ReadyAcoustics.com

[AStacy2]

Cool, thanks for the info Joel. I'm not an acoustician, but I'm glad you are. According to the website you posted, why does by looking at the different thinknesses of these, sometimes the values don't make sense to me. Like at 250hz, OC703 4'' plain on wall absorbs better than OC703 6'' plain on wall ect? Why is this? Thanks.

[Ready Acoustics]

I'm NOT an acoustician. I am knowledgeable in acoustics and acoustical performance products, and I am an inventor, but I am NOT an acoustician.

Acousticians take years of academic courses, write thesis papers and receive a very, very hard earned degree in this physics science. Some folks fancy themselves "acousticians" and even use the term haphazardly to describe themselves, but real acousticians are few and far between. And make no mistake about it, acousticians base their lit and arguments on the principal truths of acoustic science, not solo theories. I look at the science and the facts, and leave the pixy dust and "magic" numbers to those who want to believe in such.


I'm headed to the data you mentioned now.


Joel

[Loren Littlejohn]

Originally Posted by Ready Acoustics

Don't look at R value unless your only concern is heat transfer and sound (energy transfer) between rooms. To control modal issues in your room, to focus your mix and to finally make your low end (in your mix) translate well, you need to consider Sabins and Coefficients.


Check out this site:

Bass Traps Network (I moderate there)

...and this site:

http://forum.studiotips.com (this site is moderated by acousticians (real ones) and is frequented by acoustical engineers, acoustic physicists and all sorts of people who do this for a living.



~ Joel
ReadyAcoustics.com
www.myspace.com/powermadband

AWSOME.

Seriously this thread is gold.

[Force666]

Rockwool rules. You can trap bass with it and you can grow weed in it. What more could you ask for?

[dreamcatcher]

Originally Posted by Ready Acoustics

Thanks for this thread. It's enjoyable speaking with folks who demand truth, and I hope some of this information helps us get to that end.


Cheers!


Joel
ReadyAcoustics.com

TERMINATORRRRRRRRRRR!!!!!!

[Ready Acoustics]

Originally Posted by dreamcatcher

TERMINATORRRRRRRRRRR!!!!!!

Haha, dude you're killin me.




Joel

[aortizjr]

That is a great youtube tutorial.

For mine I use 8 # Density Mineral Wool. When I read all the stuff, I thought understood the numbers that higher density meant better absorption.

Anyway regardless they do work very well and the price was very nice. Way cheaper and easier to get than the 703 or 705. I got them locally at a great deal. You have to call an insulation supplier. They seem like they only sell to contractors, but they sell to anyone with cash.

For the frame, I used aluminum drywall beading. A few cuts and bends with sheers. Built a square frame for the top and for the bottom. Then sandwiched the mineral wool between them with 4" corner pieces to hold them together. Then the whole thing was riveted together. For covering after that, I wrapped them with dyed muslin on the front, then a white piece for the back. Used hot-glue to keep the fabric on.

To hang them I used eye bolts and nuts and zip ties. Worked out really well. I also broomstick tied the front fabric to give a texture.

I can't remember what I paid for the Mineral wool. But it was like $1 for each drywall bead, $.69 a yard for the muslin, $10 in dye for the whole lot, hot glue and rivets, maybe another $10 for the whole thing. So it was really economical. I remember it basically worked out to being the same as the super cheap and crappy foambymail.com 2" stuff. But with this I get 4" for the same square footage and way better absorption and low frequency absorption.

Yeah I might be getting some reflection from the beading, but I figured that some reflection is still ok.

But I don't think you need pegboard or something for the back. With the beading, they rigid enough to move around. I use a couple as mobile panels and they work very well.

And from the video, those seem like they would be ok to move around as well. But if you are just hanging them, those will definitely work great and will probably take less time than mine did

[TheIllicitOne]

I'd like to see pics of the stuff everyone has built. Very interesting stuff to me!

[Pot]

u all got me wanting to build my first bass traps.....
At the moment i couldn´t find any dealer of Owens Corning in my country or even spain

[Daunt]

Originally Posted by Pot

u all got me wanting to build my first bass traps.....
At the moment i couldn´t find any dealer of Owens Corning in my country or even spain

You can also use Paroc COS-5 rockwool. Can you find that?

[Pot]

Originally Posted by Daunt

You can also use Paroc COS-5 rockwool. Can you find that?

well what u suggest is rockwool right?
I was trying to get that specific material which is fiberglass.
if it proves too difficult i´ll get rockwool instead

[Wolfeman]

Originally Posted by Pot

u all got me wanting to build my first bass traps.....
At the moment i couldn´t find any dealer of Owens Corning in my country or even spain

Many other companies make the same dense fiberglass stuff as Owens Corning.... Just head to your nearest insulation supplier, tell them what you want, and they will get it for you.

[Pot]

will do when i have the time......my work is very time consuming.

[thefish666]

Found a website for Building Better Bass Traps

Also found a forum from EQ mag dedicated to Acoustics....Ethan Winer: Acoustics Forum

[Ready Acoustics]

Originally Posted by Wolfeman

Many other companies make the same dense fiberglass stuff as Owens Corning.... Just head to your nearest insulation supplier, tell them what you want, and they will get it for you.

Many companies do indeed make acoustical insulation. The best product we've worked with in Europe, is Isover.

Google "Isover" in your particular country, to see of they offer it near you. It is the closest thing to Owens Corning 705/ 705 from a European Manufacturer.

Easy DIY Bass Trap Tutorial

[Harry Hughes]

Epic bump, but heh, saves me from having to search for the thread
Cool video btw, Ready Acoustics

[Metaltastic]

I'd say if anyone's entitled to pull a necrothread, it'd be that fellow

[::XeS::]

If you follow this video, take care of not put the glue as he says. If the glue touches the screw, it destroy the screw after awhile, because it corrodes the metal. If you wanna put some glue, do it, but take care it doesn't touch the screws

[lordtech]

Ready Acoustics, do u send ur products to Brunei?

[FireStorm Studios]

Great thread! Just ordered my CO703 from Ready Acoustics, going out to build the frames now. Glue corrodes metal screws, I would have never known. Thanks for all the info.