Source
r/Acoustics•
StringerBull

Seeking moderate acoustic performance without sacrificing aesthetics in a small room

I want to treat a 14"x12" office without using bulky panels on the walls. The room will mostly be for playing acoustic guitar and listening casually to music. I just want to tame the room enough to sound decent, mostly for the sake of the guitar.

How effective is 2" rockwool 80 flush against the wall? How much effectiveness is lost when there is zero space between the wall and the insulation. I don't want to make panels that are greater than ~2" off the wall.

I only want to start this project if the panels will have a decent effect on the performance of the room for playing guitar. I've built 4" bass traps before and know the importance of good, gapped treatment, but I just don't have the space in this room.

Thanks!

Posted Aug 13, 2019, 5:57 AM UTC

29
baconost•

Have you considered treeating the ceiling? I put a lot of office style acoustic panels in my ceiling and am happy with the results. The wife isn't too happy with the aesthetics even though it is relatively discreet.

3
StringerBullOP•

I have considered the ceiling. My plan was a panel or two for the walls and maybe one for the ceiling.

Again, not aiming for perfection, just some decent taming.

What do you mean "office style" panels?

1
baconost•

I mean plain white square panels made of dense mineral wool, typically seen in office spaces. The ones I used are called ecophon master b and you can easily glue them to the ceiling.

1
SkoomaDentist•

Consider if you can disguise the panels as artwork. At least GIK Acoustics sells panels with artwork printed on them and I can't imagine that it would be so difficult to source elsewhere either (or you could drape a printed cloth on top of the panels yourself). I've seen photos of some rather stylish designs where a large and thick panel has been disguised essentially as a stylish design feature.

2" panels will be effective down to perhaps 300 - 400 Hz. A gap extends the range by about 2/3 octave downwards. The reason gapping is recommended is that it costs essentially nothing compared to doubling the panel thickness itself.

In your situation I wouldn't even consider bass traps since their effectiveness is inherently limited unless you cover a lot of space with them.

2
StringerBullOP•

What about a small gap? Is something like 1/2" gap for a 2" panel meaningfully different than just 2" flush against the wall?

I'm trying to limit the distance that the panels protrude from the wall. I don't want something that sticks out 4" or more.

1
SkoomaDentist•

The extension pretty much scales with the gap size up to when the gap is same depth as the panel. After that the effectiveness starts to go down (so don't make the gap too large). If you're constrained more by the protrusion than cost, then it's better to use all of it for absorption material. So 3" - 4" if you can and otherwise just put 2" there.

1
PierreLunaire•

Having no airgap behind your panels will mostly reduce the low end absorption. For your purposes, it shouldn't be a huge issue, and you should be fine putting 2" panels flush to the wall. Also consider using the ceiling.

2
yeky83•

How effective is 2" rockwool 80 flush against the wall? How much effectiveness is lost when there is zero space between the wall and the insulation. I don't want to make panels that are greater than ~2" off the wall.

https://www.bobgolds.com/AbsorptionCoefficients.htm

2
ChrisParkerJones•

Should be fine sticking a few of your rockwool panels on the wall and as another user said, you can cover these in a fabric. Potentially you could get canvases printed and just fit in a rockwool panel cut to fit behind/inside the timber frame. No one but you would know it's even there. This is more or less what an acoustic wall panel is anyway.

Soft furnishings will help to, maybe a sofa or a soft office chair? Shelving and bookcases will provide a small amount of absorption, plus some diffusion which is beneficial.

Even sticking some foam on the top of a wardrobe, hanging some coats pin the back of the door... Hanging your guitar bag somewhere... Every little helps.

Presumably you have carpet as well, otherwise, chuck a nice chunky rug down.

1