Cheap elements

[ittam]

I plan to make this kind of multipurpose absorbers/gobos.
The material is from the ceiling of a restaurant used to cover the various tubes for the air conditioning and for the acoustics.
The units are only 2cm thick but I´ll stack them to thikness of what seems good.
There will be an airspace between front and back because of the stand married between
and the whole thing will be covered with some cheap breathing textile.
I´m a sound recordist, so the attached image might be out of
tolerances, but if it explains something...
Cheers and regards Matti
Edit ...No Pictures from me because of the max file sice but the idea
would be 2 layers of this material then the stand baked in and then the same layers of
this free material, much like OWENS 703. I´m in Europe and don´t know the exact type of this acoustic material,
but I know this is quality material, not the best though.
Matti

[c7sus]

Use pegboard for the center of the wafer and you have a Helmholz resonator.

[ittam]

Yea but dont mind to start calculating. I will make
semipro measurments while making and moving these around
with a decent acoustic measurment program the name of wich
I cannot remember just now as it´s not in this computer....
And then much by ear to mathc my impression of decent reproduction;
these combined I guess. I have measured rep. +/- 3 db from
40hz to 15khz now but only in one place in my room.
So the purpose of these elements should be to even the
resp. curve and when recording something to make a space,
so to speak.
Regards Matti

[ittam]

I'm a lazy man, so this is what I ended with.
The stands are made of an old bookshelves "stairs" from my attick.
Total thickness of the unit(s) is 6 inches.
I just tied them with electricians copper ground wire.
Will cover with the material in the picture.
Total cost 20€ for the canvas/ 4 units.
Cheers Matti

[timboZ]

Originally Posted by c7sus

Helmholz resonator.

Is that a good thing or a bad thing.

[ittam]

Resonators are calculated for one specific frecuency, mine are "unprofessional"
broadband absorbers.
Matti