Bass Wall traps: To FRK or not

[DanDan]

I tested FRK vs none on Cloud and Side reflection traps.
Probably different from your question, the FRK was on the surface NOT facing the room, but there was a considerable airgap, say 6 inches.
Decay in the 80Hz area dropped from 0.3 to 0.2.
OC 703 FRK... to foil or not to foil????
FRK is probably more effective again on the side facing the room. It will also bounce HF back at you to some extent. Whether the HF is wanted or not is another matter, but such panel traps can be angled to prevent HF flutter.

Not sure what to say about the summary. Thickness, density, and airgaps are all dealt with by Andre in the Q4Avare thread.

DD

[Ethan Winer]

Originally Posted by 4 the Max

any advice on whether the other non-corner (wall and ceiling) bass trap panels should have FRK?

Here's my logic: Corners are not usually at direct refection points, so those should always be FRK. The front wall is behind the speakers, so unless you have dipole speakers that send sound equally front and back, those too should be FRK. The rear wall behind you can be FRK or not. If the wall is closer than about ten feet from your ears, I would not use FRK. If it's farther, I'd probably use alternating vertical "stripes" of FRK, plain, FRK, etc. I use ten feet as the cut-off because closer than that and those reflections are "early."

--Ethan

The Acoustic Treatment Experts

[npatro22]

So if I had the choice to put FRK on my cloud facing the ceiling should I? My room is small 13x13x8 foot ceiling? Will it help substantially with low end absorption?

[Glenn Kuras]

Originally Posted by npatro22

So if I had the choice to put FRK on my cloud facing the ceiling should I? My room is small 13x13x8 foot ceiling? Will it help substantially with low end absorption?

If the cloud is in the early reflection area then no you would not want to use FRK on the fronts.

[AwwDeOhh]

Originally Posted by Glenn Kuras

If the cloud is in the early reflection area then no you would not want to use FRK on the fronts.

+1
The exception would be:
Unless you had a tall enough ceiling to angle the cloud in such a way as to deflect the sound beyond the listening position.

[Ethan Winer]

Originally Posted by npatro22

So if I had the choice to put FRK on my cloud facing the ceiling should I? My room is small 13x13x8 foot ceiling? Will it help substantially with low end absorption?

Yes, if the FRK is facing up it will absorb more bass than non-FRK, but will still absorb mids and highs fully as if there was no FRK.

--Ethan

[npatro22]

Thank you everyone

[Hyder boy]

Originally Posted by Ethan Winer

Here's my logic: Corners are not usually at direct refection points, so those should always be FRK. The front wall is behind the speakers, so unless you have dipole speakers that send sound equally front and back, those too should be FRK. The rear wall behind you can be FRK or not. If the wall is closer than about ten feet from your ears, I would not use FRK. If it's farther, I'd probably use alternating vertical "stripes" of FRK, plain, FRK, etc. I use ten feet as the cut-off because closer than that and those reflections are "early."

--Ethan

The Acoustic Treatment Experts

I assume you are saying to face the FRK to the room, there has been talk of facing the wall.
Thanks

[Kyleseglin]

I'm trapping a 4x6x7.5 room. I'm pretty much straddling all corners with 703 in 4" thick panels. I did not opt for frk bc its a small room.. I straddled the ceiling to side wall junctions with full 24x48x4 panels leaving a 1' or so air gap behind the panels in the corner space. According to glens calculators on the site I found I need about 56 sq ft of coverage.. Am I good to go with my 703 all over? Thanks you guys are so helpful I've read countless posts by you all.

[Kyleseglin]

And there are a couple of panels on the ceiling too

[Ethan Winer]

Originally Posted by Hyder boy

I assume you are saying to face the FRK to the room, there has been talk of facing the wall.

Exactly. If the FRK is facing the wall, it might as well not be there at all.

--Ethan

[Hyder boy]

Originally Posted by Ethan Winer

Exactly. If the FRK is facing the wall, it might as well not be there at all.

--Ethan

Thanks

[DanDan]

If the FRK is facing the wall, it might as well not be there at all.

Of course, unless there is a thermal or vapour reason to have it there.

But remembering, if there is an air gap, then there is a small increase LF absorption.

DD

[Hyder boy]

Originally Posted by DanDan

Of course, unless there is a thermal or vapour reason to have it there.

But remembering, if there is an air gap, then there is a small increase LF absorption.

DD

That's what I was getting at.