Bass Trap Design Sanity Check

[Todzilla]

Gradient Pressure Fans,

Here is my proposed design for a corner bass trap. I think I may have the concept articulated, but I yearn for some feedback.

The view is from above, showing a big triangular shaft of space, closed at the top, with a thin sheet of plywood and some insulation behind it to tame things.

I thought the triangular shape would give it more of a broadband low-end application.

Did I get it right?

BTW, I'll build some cylindrical ones for moving into specific locations.

Thanks

 

[longsoughtfor]

Todzilla - I would add rigid insulation on the corner walls inside the trap as well. Aside from that, the important thing is that the whole thing is sealed against the wall, floor and ceiling to create the pressure gradient.

Cheers
Kevin.

 

[Todzilla]

You mean like this?

 

[longsoughtfor]

Yup.

 

[John Sayers]

What you are building here is a panel absorber which will be tuned to the frequency = to the resonate freq of the plywood.

Here is the solution I sent sjoko for the rear of his control room.

Sjoko rear corner

cheers
john

 

[Todzilla]

John,

Thank you.

Wow, I guess I misunderstood the whole broadband bass trap thing. I am trying to interpret your plans and I have a couple of questions:

1. Do you mean that all the gaps between the slats are 1/8", or is there some variation that ensures different frequencies are trapped?

2. Orientation of the 2" X 4"s - are you showing the 2" side as the side which will face the room?

3. Are your dimensions of 2" X 4" lumber exact? Because here in the states, what we call a 2X4 is more like 1.5" X 3.5"

4. Would you loosely fill the void with insulation, or leave some air?

I am intrigued and somewhat intimidated by your design, but it looks fairly easy to construct with just 2X4s.

Do you suppose it'll still work in this hemisphere where sound rotates clockwise? ;^)

 

[John Sayers]

Yes it's a slot resonator with the 2 x 4 using the 4" depth and the 2" facing the room. Sjoko and I discussed using 1" plywood instead which would give more diffusion and produce more slots. I'm not sure which one he decided to go with.

Yup fill the cavity with insulation. Good place to throw any leftover insulation offcuts you may have during construction.

The 2 x 4 is a standard construction size. If it's dressed all round it may have a 1/8" taken off by the plane but I would expect it to be 2" x 4". can't see how it could be dressed down to 3.5"??? Note the sizes go up to 6" x 2" to get the depth for the low frequencies.

cheers
john