Will 9mm felt panels help with anything?

[C0mbat]

I have my Hi-Fi in a pretty small roughly 3.5x4m room that I use as an office. I have my speakers up against one of the longer walls. My desk faces that wall about two thirds back. Behind me there is a sloping roof that starts from 1m up and slopes above my head. In theory that means that sound is reflecting off that slope directly on to me. Can I tell? No. But I do wonder.

I have installed reclaimed teak panels behind me in the 4x1m vertical space but the sloping roof above it is bare.

Would I notice much improvement from sticking on a load of 9mm thick 30x40cm felt panels that you can buy for about £20 for 12 on ebay? It would probably only cost me £60 to do but is it worth the bother?

 

[tmtomh]

I have my Hi-Fi in a pretty small roughly 3.5x4m room that I use as an office. I have my speakers up against one of the longer walls. My desk faces that wall about two thirds back. Behind me there is a sloping roof that starts from 1m up and slopes above my head. In theory that means that sound is reflecting off that slope directly on to me. Can I tell? No. But I do wonder.

I have installed reclaimed teak panels behind me in the 4x1m vertical space but the sloping roof above it is bare.

Would I notice much improvement from sticking on a load of 9mm thick 30x40cm felt panels that you can buy for about £20 for 12 on ebay? It would probably only cost me £60 to do but is it worth the bother?

Probably not. That's pretty thin, and I don't know how effective felt is as an absorber. If you are experiencing noticeable flutter echo in the room - like you clap your hands and you can clearly hear the clap echoing repeatedly - then they might help with that. But beyond that, they're unlikely to be effective.

 

[Salt]

You will know after buying and installing the felt and having investested into a Umik 1.
Investment is lower than €200.

 

[Salt]

And there are things like these (absorber-diffusor):
https://www.obi.de/p/1246974/akustikpaneel-wandverkleidung-eiche-natur-auf-akustikfilz-grau-240-cm

 

[C0mbat]

You will know after buying and installing the felt and having investested into a Umik 1.
Investment is lower than €200.

I already have the umik 1. I use REW for basic measurements but probably haven't scratched the surface. Should I be using a particular reading to check for reflections before buying the felt?

 

[Doodski]

I have my Hi-Fi in a pretty small roughly 3.5x4m room that I use as an office. I have my speakers up against one of the longer walls. My desk faces that wall about two thirds back. Behind me there is a sloping roof that starts from 1m up and slopes above my head. In theory that means that sound is reflecting off that slope directly on to me. Can I tell? No. But I do wonder.

I have installed reclaimed teak panels behind me in the 4x1m vertical space but the sloping roof above it is bare.

Would I notice much improvement from sticking on a load of 9mm thick 30x40cm felt panels that you can buy for about £20 for 12 on ebay? It would probably only cost me £60 to do but is it worth the bother?

If you are on a budget and want a effective absorbent panel look about for used office divider panels. They are 2m x 1m x ~10cm. They will deaden your room and the imaging should be more localized rather than all around the room reflections. 2 should do it.

 

[C0mbat]

If you are on a budget and want a effective absorbent panel look about for used office divider panels. They are 2m x 1m x ~10cm. They will deaden your room and the imaging should be more localized rather than all around the room reflections. 2 should do it.

My issue with that is the limitations in where I can put them. Something 10cm thick won't work for the sloping roof. I could possibly hang them from the ceiling but that would be going quite extreme.

 

[kemmler3D]

I already have the umik 1. I use REW for basic measurements but probably haven't scratched the surface. Should I be using a particular reading to check for reflections before buying the felt?

Look at the ETC and you can see reflections as small spikes after the initial impulse. Depending on the timing of the spikes you can determine which surfaces are causing them by converting that into a distance.

9mm felt will help with the highest frequencies but only that, the tendency will be to make the sound a bit unbalanced by pulling treble (and nothing else) out of the reflected sound.

 

[Jost Buergi]

I could possibly hang them from the ceiling but that would be going quite extreme.

May I ask why that’d be extreme? I just finished hanging 5 cm white Basotect panels from the ceiling with 4 cm space to the ceiling which nearly works like 9 (5+4) cm panels. The total panel size is just under 5 square meters in a room of 40 square meters. I must admit I spent quite some time to get everything properly positioned but everytime I walk in I am immediately amazed how much the acoustic fingerprint of that room has changed.

I agree with @kemmler3D , 9 mm of felt only absorbs higher frequencies.

 

[tmtomh]

If I had to choose only one surface to treat in a typical room, I'd probably choose the ceiling. (Assuming of course that the floor already had carpet or a rug of some kind.)

 

[Jost Buergi]

And there are things like these (absorber-diffusor):
https://www.obi.de/p/1246974/akustikpaneel-wandverkleidung-eiche-natur-auf-akustikfilz-grau-240-cm

Those have become quite common lately. We even have a thread on them here.

 

[jaakkopetteri]

Those have become quite common lately. We even have a thread on them here.

Way better results than most people think, even if the validity of RT60 measurements are questionable in domestic rooms

 

[ozzy9832001]

My issue with that is the limitations in where I can put them. Something 10cm thick won't work for the sloping roof. I could possibly hang them from the ceiling but that would be going quite extreme.

Ceiling treatments are quite common. Often the areas in the FR affected by the ceiling are in a critical area and sound nasty if they cause constructive interference.

A sloped ceiling would be worse since it's dimensions change over a period making more potential issues.

I'd recommend buying some 4" panels for the ceiling and hanging them with a 4" airgap between the ceiling and panel. This will give you maximum effective range and some decent absorption. The critical zone would be between you and the speakers, but they will gain some benefit even being above or behind as well.

It's hard to say whether treating just the ceiling would be the most beneficial, but in your case, I would say that's probably true.

In theory, treating all surfaces evenly, so absorption is consistent across all surfaces, is the best option. In practice, that doesn't always work out.