A Guy from Holland needs help with absorbers

[Leonneke]

Hello Guys;

First of all, I live in Holland, so excuse my English writing.

I am planning to built sound baffles my self. The main goal is controlling the low frequensies. The construction i'm planning to make is similar to the attached picture.

MDF in the middle and on both side Rockwool 213 ( semi high density ).

The size will be something like 180 centimeter x 60 centimeter. If I am correct this is about the same as 6 x 2 Foot ( 70 inch x 23 inches ).....

What I wanted to know is the following:

How thick should the MDF be ?? I mean, should it be heavy to make it work better on the low frequencie ......... ????

Thicker & Heavier is always better ???

How thick should the Rockwool be ??????

Thicker & Heavier is better ??????

Is it wise to mount different holes in the MDF board to create "air" ... ???

Or maybe is it wise to create an AIR space between the MDF and the Rockwool by making a construction so the Rockwool may float ???

Well .......... A lot of questions but as we say over here .........
If you don't ask - you won't know .......... Leonneke

[riffster]

Hi there, I built some similar free standing units with the goal of minimizing mic bleed between two musicians. I used 4" of insulation on each side of 3/4" MDF. There are plenty of great panel projects on this forum.

I think for what you are trying accomplish, the addition of MDF might be unnecessary - also hanging from the ceiling might cause some support issues as MDF is pretty heavy. I think a box with 4" of dense insulation would suit your needs. Someone correct me if I'm wrong. You should probably tell us more about your room so some of the real pros can help you.

[RecBetterAudio]

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They are free standing baffles that are moveable

[bpape]

That hanging style of baffle works on a little different principle than standard absorbers. The idea with those is to actually allow them to move and swing a bit - thereby absorbing some bass energy. Each progressively longer baffle will swing at a different frequency just like a pendulum on a clock which is adjusted by moving the mass up and down on the shaft.

There are a variety of ways to arrange a group of these depending on your requirements and layout options.

In general, more mass = lower frequency but less efficiency also. Start out with something like 3/8 or 1/2" plywood. Make sure to hang them far enough apart that they don't bang together.

Bryan