thin foil on an acoustic panel

[JJacek]

I have heard that an acoustic panel covered with a thin foil adds to some acoustic problems.

Is it true?

[BertKoor]

Panels are covered with sound absorbing foam.
If you put foil over that, it reflects instead of absorbs.
So yeah, putting foil over it defeats the purpose.
(you can use some light fabric instead of foil)

[JJacek]

But this is only true for the top end of frequencies, right?

[JJacek]

bump

[BertKoor]

Why would you put foil over acoustic panels?
Just don't mess with them.

[AnX]

But this is only true for the top end of frequencies, right?

wrong

you want something that absorbs, not reflects, no matter what the freq

[bungle]

If your room is too flat and you wish to liven it up a bit, yes use some reflective surfaces.
The idea that acoustics is all absorption is complete and total nonsense proliferated by various forum full of people that have never worked in a nice sounding room in their life.
The likelihood that your room is too flat vs too lively is very very low though, so yes, you can use foil strips (why foil though?) more common is pegboard because you get some diffusion and reflection and with foam behind some absorption too.

What exactly are you trying to achieve ?

Simple rules for home acoustics.
1 Concentrate on your bass traps.
2 Have plenty of surfaces with different absorption and reflectivity.
3 With plenty of stuff, diffusion is free (Bookcases are an old trick)
4 Get used to the room and stop worrying.

[AnX]

I have heard that an acoustic panel covered with a thin foil adds to some acoustic problems.

Is it true?

thats insulation, not an acoustic panel

acoustic panels have no foil

[Wannae]

It's any good if i make my acoustic panels 4 inch? I don't want a dead sound in the room (just for mixing and composing, no recording).

[Ah_Dziz]

Get some free hardwood scraps, wood glue, and some pegboard and build diffusers if you want to make sure you don't have high frequency modal buildup. If you want to build absorbers and need to coat them somehow just use cloth. Or stiff rockwool with an air pocket inside along with your foam.
JJ