How about these for Bass traps?

[Gorty]

I have access to this pipe insulation which is Rockwool, it is 3 1/4" thick and 15" in diameter.
I have a small room room which is approx 3m x 2.5m so I have not got a lot of room to play with. I am in the process of constructing broadband absorbers for my listening room and would like to use this pipe insulation covered in cloth and placed in my corners for Bass traps, using the conventional 24" x 4" is going to cause serious room problems because of the smallness of my room.

I am interested on some feedback on this idea! The profile of this particular product being round would have some benefits I'm sure!

I have done a lot of research and have read Ethan Winers arcticles on acoustic treatment, so from what I have read my opinion is that they would be not the ultimate choice but given what I have to work with I would appreciate anyones constructive input!

Thanx in advance!
Kev

Here's a pic of the insulation!

[Gorty]

Here's another picture of the insulation I'm thinking of constructing my Bass traps out of, Did I mention I have access to this product at no charge!

[bigwillz24]

the shape makes it look like it would make a great diffuser...

but I have no idea when it comes to these things...

If you didn't stay on the other side of the earth i'd ask if i could buy some from you.

[Gorty]

Originally Posted by bigwillz24

the shape makes it look like it would make a great diffuser...

but I have no idea when it comes to these things...

If you didn't stay on the other side of the earth i'd ask if i could buy some from you.

If you weren't on the other side of the earth I would sell you some ......really cheap!

[bpape]

If you're going to use that material, I'd leave it as WHOLE rounds and stand them up in the corners. That will do a better job.

The difference between these and 2x4 absorbers is that these will have the front MUCH closer to the boundaries (reducing the depth of frequency it can deal with) and also have much less surface area exposed to the room.

You will likely need these in pretty much all of your corners - horizontal and vertical to compensate for the area. For the depth - well - depth is depth. You might also consider some deep bass membrane traps but if your room is that small you might not have that luxury.

Bryan

[Gorty]

Thanx for your reply Bryan, I was hoping you would turn up!

I can put these in all my corners, however I assume I would be better off constructing the traps that go across the corners giving me more surface area for contact.

The size of my room however would still limit me to approx 15" across the corners.

Having them left circular I hit the room size problem again. I do have access to the same product that is 10" in diameter that I could leave circular in each corner!

Any good?

Thanx again
Kev

[Gorty]

Just a quick one, seems the more I read the more I get a little confused. I have a small room so basically I need bass trapping in my corners min 4" thick and broadband absorbers 2" with 1" air gap for reflections.

My room is mainly for critical listening for my mixing process!

Am I on the right track?

Thanx
Kev

[bpape]

The smaller the room, the more broadband most treatments need to be. I've done some pretty small rooms where pretty much everything ended up being 4"

If you must, use 10" diameter in the vertical corners and the larger ones in the horizontal corners.

If you can find some REALLY large diameter - like 24", then you could cut into quarters and mount them to the 2 perpendicular surfaces.

Again, you just need a certain amount of area, a certain amount of thickness, and good distance from the boundary. Whatever you need to do to get these things is the way to go.

You can also put smaller diameters inside larger ones to not only provide additional thickness - but if you space them apart inside each other - you force the wave to change the medium through which it traveles more times - all of which make it more efficient.

[Dan Merrill]

that stuff is quite similar to the knauf pipe insulation I've used to make tube traps. Although the knauf is only 1" thick if I remember correctly. I use them for lots of things- including the front corners of my control room, and the extra ones are easily placed around the studio for small gobos as needed. I have a mix of tubes and panels in my control room and like them both.

I <think> the larger the diameter- the further they protrude from the corners and the lower the frequency absortion. The plans call for them to be sealed and mine are, but I'm not so sure they really need to be- I mean, flat panels across a corner are not sealed absorbers and they do the job.

Here's a link for building this type of trap -in case you haven't found one yet.

http://www.teresaudio.com/haven/traps/traps.html

and free is always good for DIYers :-)

[LemonTree]

Originally Posted by Dan Merrill

that stuff is quite similar to the knauf pipe insulation I've used to make tube traps. Although the knauf is only 1" thick if I remember correctly. I use them for lots of things- including the front corners of my control room, and the extra ones are easily placed around the studio for small gobos as needed. I have a mix of tubes and panels in my control room and like them both.

I <think> the larger the diameter- the further they protrude from the corners and the lower the frequency absortion. The plans call for them to be sealed and mine are, but I'm not so sure they really need to be- I mean, flat panels across a corner are not sealed absorbers and they do the job.

Here's a link for building this type of trap -in case you haven't found one yet.

http://www.teresaudio.com/haven/traps/traps.html

and free is always good for DIYers :-)

God! they look ugly

[bpape]

All a matter of preference I guess. I have customers who want the tubes instead of panels because they think they look better.

[Gorty]

Thanx guys for your feedback, I appreciate it so much.

Thanx Bryan and thanx Dan for your link!



One more question!

I know that ideally all my absorbers in my small room need to be broadband eg 4" thick. Because my room is quite small room is very restricted, would I be wasting my time if I made all my panels with 2" fiberglass and a 1" air gap?


My room really is quite small!

Kev

[bpape]

That would probably be OK for the reflection points. For the bass absorbers make them 4" minimum.

[Gorty]

Thanx again Bryan,

I'm off to construct!!!!

I'll post some pics of the work in progress!

Kev

[RICK FITZPATRICK]

That would probably be OK for the reflection points. For the bass absorbers make them 4" minimum.

You need to place them where modal frequencies terminate. Since a rooms 3 dimensions dictate the wavelengths that are modes, and these wavelengths are very long compared to mid and high frequencies, it requires placing treatment where these long wavelengths occilate, which is in the corners. ALL corners. Stradle a corner with 4" panels, floor to ceiling, and or along wall/ceiling intersections. Better yet, stack diagonals cut from these panels, to make "superchunks" of rigid fibrglass.

[Gorty]

Thanx Rick,

I am going to construct some traps for all my vertical corners firstly, 4" thick but can only make them approx 12" - 15" wide because of the smallness of the room!

I will then place some traps across my horizontal corners around the room using the product I posted pics of at the beginning of this thread!

For my first reflections will it be sufficient to use the 2" rigid fiberglass in a frame up against the wall or will it be a major benefit in having a 1" air gap between the wall and the 2" glass?

Thanx once again everyone for all your help!

[myfipie]

<For my first reflections will it be sufficient to use the 2" rigid fiberglass in a frame up against the wall or will it be a major benefit in having a 1" air gap between the wall and the 2" glass?>

It will help if spaced off the wall.. We just did some testing of our panels "A" mount (againest the wall) and "J" mount with space.. The high end absorption did increase due to sound also getting behind the panel.. You may want to think about spacing it off 2".. Also it will help with getting more mid bass..
You can see the testing at http://www.gikacoustics.com/absorption.htm if you would like to see the numbers.

[Gorty]

Originally Posted by myfipie

<For my first reflections will it be sufficient to use the 2" rigid fiberglass in a frame up against the wall or will it be a major benefit in having a 1" air gap between the wall and the 2" glass?>

It will help if spaced off the wall.. We just did some testing of our panels "A" mount (againest the wall) and "J" mount with space.. The high end absorption did increase due to sound also getting behind the panel.. You may want to think about spacing it off 2".. Also it will help with getting more mid bass..
You can see the testing at http://www.gikacoustics.com/absorption.htm if you would like to see the numbers.

Thanx myfipie for your info!

Very informative, I'll be spacing my panels off the wall after looking at your test results. Thank you very much!

[RICK FITZPATRICK]

You can see the testing at http://www.gikacoustics.com/absorption.htm if you would like to see the numbers.

Thats odd. According to this, there is NO standard for corner tests, and frequencies below 125 hz are prone to errors. Hmmm.

[Gorty]

Here I go again!

Checking out everything in my little room last nite in regards to available room, I was thinking that I would make my Bass traps for the vertical corners to straddle the corners but only from the ceiling to about 2 and a half feet from the floor. I really need the room.

I know ideally they would be better to cover the whole corner, would I be wasting my time or would it be somewhat better to do this than not at all?

I really am restricted by my room size!

I can cover nearly all my horizontal corners without a problem!

Thanx again guys for your help and advice in advance.

[Ethan Winer]

Rick,

> frequencies below 125 hz are prone to errors. <

There's a related discussion going on now in one of the Home Theater type forums I visit. One of the experts there pointed out an interesting section in the ASTM C-423 standards for measuring absorption I had forgotten about. That section reports the result of a "round robin" test that was done among a large number of certified labs. Each lab was sent in turn the exact same physical sample to measure, and all of the results were tabulated. Even at 125 Hz, which is within the certified range, the labs varied by 50 percent! So forget below 125 Hz. Even at 125 Hz these certified measurements can vary wildly.

--Ethan

[Gorty]

Thanx Ethan.

[Gorty]

I've managed to have the product which I posted pictures of at the beginning of this thread (pipe insulation, rockwool) cut without the centre taken out for the pipe!

In other words the product will be cut from a solid cylindrical piece of rockwool into 4 pieces of pie so they will fit straight into my corners. The diameter will be approx 450mm, so from the corner of my room they will protrude 225mm in radius (approx 9").

Once again I am seriously limited in room size so I think these will be a good effective product for my Bass traps!

Any thoughts!

Thanx in advance!

[RICK FITZPATRICK]

Any thoughts!

What frequency has a 1/4 wavelength 9" long.

[Gorty]

Originally Posted by RICK FITZPATRICK

What frequency has a 1/4 wavelength 9" long.

Forgive my lack of acoustic engineering wave length frequency knowledge....

Will I be wasting my time with this product?...............hopefully I'm not wasting your time Rick!