Which bass trapping should I use?

[jrubbernek]

I'm thinking about treating my corners with super chucks corner bass traps, or just the regular "straddling across corners bass traps". Super chucks just cost too much...help me figure out which is more cost efficient and effective...
please help

thanks guys..

[spm_gl]

I'm a resonator advocate, but that's not the question here. Superchunks, etc, don't really make sense. Actually a great way to make money, cut foam into pieces, measure the absorption, and sell it at a huge profit.
Build the usual gearslutz corner 703 or whatever panel.

[Glenn Kuras]

Super chunks are great but if your working on a tight budget then go with 4" straddling the corners.

[Weasel9992]

Originally Posted by spm_gl

Superchunks, etc, don't really make sense.

Why do you say that? We have test results that tell a very different story...corner-filling bass traps absorb better down lower than 4" panels straddling corners.

Frank

[spm_gl]

I simply find an absober that does 30% on 125Hz and 90% on 4000 (just examples) is not what I'd call a bass absorber. I prefer well tuned resonators for bass, that way I can control the mids and highs where and how much I need to.
Additionally, I really find foam to be far too expensive for what it is. A lump of glass wool in the corner works just as well in a home (!) studio, and supports your local building supplier.

[Glenn Kuras]

Originally Posted by spm_gl

I simply find an absober that does 30% on 125Hz and 90% on 4000 (just examples) is not what I'd call a bass absorber. I prefer well tuned resonators for bass, that way I can control the mids and highs where and how much I need to.
Additionally, I really find foam to be far too expensive for what it is. A lump of glass wool in the corner works just as well in a home (!) studio, and supports your local building supplier.

edit: I misread your post. sorry

Glenn

[Weasel9992]

Originally Posted by spm_gl

I simply find an absober that does 30% on 125Hz and 90% on 4000 (just examples) is not what I'd call a bass absorber. I prefer well tuned resonators for bass, that way I can control the mids and highs where and how much I need to.
Additionally, I really find foam to be far too expensive for what it is. A lump of glass wool in the corner works just as well in a home (!) studio, and supports your local building supplier.

Oh...well, yeah if we're talking about foam sure. Superchunk absorbers made from rigid fiberglass or mineral wool absolutely do NOT perform that way though...just about the opposite, actually.

Frank

[spm_gl]

I thought we were talking about foam. If not, my bad. But you'd have to cover the wool with foil to prevent high-frequency absorption.

[spm_gl]

Glenn, I did read your measurements (I know, you edited the post, wasn't necessary), and I really don't want to critizise you as a manufacturer. But there are so many products in the market claiming to wonderfully solve all acoustics problems (that most home studios didn't even know they have), that I tend to overreact these days :-)
I spent nearly 6 months designing our tracking and control rooms, reading everything I could find on acoustics (including Mechel, not that I undertand much of it), even ended up doing FEM and BEM calculations. Sure, I could have paid someone to do it, but I got kind of passionate about it. That's why I get a little upset sometimes. Sorry.

[Weasel9992]

Originally Posted by spm_gl

I thought we were talking about foam. If not, my bad. But you'd have to cover the wool with foil to prevent high-frequency absorption.

Yes...kinda.

If you design the panel properly, using the right density materials, then you'll absorb 2.5-3.5 times as much at 125Hz as at 4Khz. Adding an FRK layer increases that disparity, which is a good thing in some cases.

Frank

[Glenn Kuras]

Glenn, I did read your measurements (I know, you edited the post, wasn't necessary), and I really don't want to critizise you as a manufacturer. But there are so many products in the market claiming to wonderfully solve all acoustics problems (that most home studios didn't even know they have), that I tend to overreact these days :-)

Well yes you are right, there are some manufactures that can only "claim" without testing. Big problem I think. We (not to brag) on the other hand have spend a great deal of time and money in the lab to back up up our product.
BTW there are PDF (not just HTML) reports so you can see if we are cheating. If you think anything is made up then I would highly recommend contacting Riverbank Lab to get the reports from the horses mouth.

[Ben F]

Originally Posted by Weasel9992

Why do you say that? We have test results that tell a very different story...corner-filling bass traps absorb better down lower than 4" panels straddling corners.

Frank

Do you have a link to a basic design for corner filling bass traps?

[jrubbernek]

hmmm still can't decide...any links on how to make panel rezonators? and how effective they really are? I've read a few books that says adding rockwool inside a panel rezonator, will make it absorb more bass? is this true?

Still don't know which one is more effective....My room dimension is 3m(h) x 5m(l) x 3.2m(w)

[jwl]

To the OP: the answer depends on how much material you can afford. If you can afford enough material to superchunk every corner in the room (including wall/ceiling corners) then by all means do so, it'll rock.

If you can't afford that much material, then covering more corners with 4" panels will almost certainly outperform the same total amount of material concentrated in superchunks in 2 or 4 corners.

In short, cover as many corners as you can with as much material as you can.

[spm_gl]

Originally Posted by jrubbernek

any links on how to make panel rezonators? and how effective they really are? I've read a few books that says adding rockwool inside a panel rezonator, will make it absorb more bass? is this true?

There are tons of pics on the net, but you need to know exactly what center frequency you need, and you need to know the area mass of your panel. Adding rockwool (without it touching the membrane!) broadens the effective range somewhat.
Resonators are easy to build, not too difficult to dimension. But they have a very narrow range of absorption.
Oh, I just saw you've posted the dimensions of your room, so you can do a quick mode calculation, that'll tell you which frequencies you need.

[Glenn Kuras]

Originally Posted by jrubbernek

hmmm still can't decide...any links on how to make panel rezonators? and how effective they really are? I've read a few books that says adding rockwool inside a panel rezonator, will make it absorb more bass? is this true?

Still don't know which one is more effective....My room dimension is 3m(h) x 5m(l) x 3.2m(w)

spm_gl gave you the right answer, but I would not recommend starting out with them. Small rooms have problems throughout the frequency range so trying to build tuned traps for all the dips and nulls would be pretty darn hard. I would start with broad band bass trapping(as we have been talking about) and at the end if you have a few problem areas you can then build the tune traps to solve it.
Don't get me wrong I like tuned traps but it is not the ideal starting point for smaller rooms.

[spm_gl]

I actually start with tuned traps, integrating them into the construction, for the major modal frequencies. But that only works if you're doing a full-blown building job, and the room is big enough.

[bpape]

Also, it depends on how much space you have. Resonators are only good over an octave or 2 depending on the type you do. That means you just need more of them to get the decay times in line across the spectrum.

Using broadband control in the corners gets you a long way to start with and then you can add the tuned absorbers to increase absorption at specific frequency ranges as needed.

Bryan

[Weasel9992]

Originally Posted by Ben F

Do you have a link to a basic design for corner filling bass traps?

I don't have a link, but it's basically a matter of taking 48kg/m3 mineral wool or rigid fiberglass, cutting triangles, then stacking them. That's pretty much it.

Frank