have you seen these bass traps before?

[frequency_]

I was in a recording studio about a year ago, and i noticed there was two hard wood panels on corners of the rear wall in the control room, there were small holes on the pannels, small enough to fit a pencil. I asked the guy what these panels were for, and he said its bass traps. I didnt pay much attention and now it came in my mind again. I asume they worked somehow like Helmholtz resonators. Are you familiar with these bass traps? If so do you think they re effective?...more effective than rigid fiberglass? they looked something like the picture below

 

[tmix]

They do work similarly to slatted walls and hemholtz.
They are bound to have absorptive materials inside.
The benefit being it reflects high end if the room is going to be too dead otherwise.

 

[frequency_]

They do work similarly to slatted walls and hemholtz.
They are bound to have absorptive materials inside.
The benefit being it reflects high end if the room is going to be too dead otherwise.

oh i see, so would you have to "tune" these bass traps to absorb certain frequencies? or you just stick them on the wall and they work?

 

[gullfo]

you can also make them polycylindrical across the corners to add diffusion as well as broadband bass trapping.

 

[pandamonk]

I was in a recording studio about a year ago, and i noticed there was two hard wood panels on corners of the rear wall in the control room, there were small holes on the pannels, small enough to fit a pencil. I asked the guy what these panels were for, and he said its bass traps. I didnt pay much attention and now it came in my mind again. I asume they worked somehow like Helmholtz resonators. Are you familiar with these bass traps? If so do you think they re effective?...more effective than rigid fiberglass? they looked something like the picture below

Better off with rigid fiberglass. I looked into these before, and it ain't really a good idea. Helmholtz absorbers shouldn't really straddle corners. They are also tuned, so aren't recommended unless you know exactly what you're doing. Rigid fiberglass is broadband, which is much more forgiving.

 

[pandamonk]

you can also make them polycylindrical across the corners to add diffusion as well as broadband bass trapping.

Doubt something that absorbs will diffuse. The only way that'd work, imo, is if it's very dense material, reflecting mid-high freqs.

Edit: Are you recommending the perforated board used polycylindrical across the corners? If so, it would reflect and diffuse, but it would there would be no way of knowing at what frequencies it'll absorb.

 

[gullfo]

Doubt something that absorbs will diffuse. The only way that'd work, imo, is if it's very dense material, reflecting mid-high freqs.

you could use pegboard but it would be affecting the high frequencies with that number of holes. you would ordinarily drill in the required number of holes in 1/8"-1/4" plywood or seal the pegboard and push out a number of plugs - to get it to within a center frequency. the poly itself, esp straddling a corner - will absorb a decent range of bass frequencies (as well as the target freq - which will be low(er) Q = (broad(er) band = because of the poly, and insulation and corner mounting) and it will be diffusive above 500hz.

you also don't need any holes in it to be a bass trap and diffuser. its just that if you need some additional trapping using Helmhotlz techniques, its one way to do it.

it does take more space than a flat corner treatment though, and you want to generally construct it so its sealed top and bottom and also to isolate the face of it from the supports - i.e. it takes a bit more care to get it all just right...

its actually a fairly efficient bass trap and mid-high diffuser in one unit.

 

[TexRoadkill]

oh i see, so would you have to "tune" these bass traps to absorb certain frequencies? or you just stick them on the wall and they work?

No tuning neccessary. The varrying wall depth gives you a more broadband level of absorption.

I would probably agree with the others that a superchunk type corner trap would probably be better for a control room. Helmoltz seem to be better for tracking rooms where you mainly want low end absorption/ high end diffusion.