Rockwool panels... density and thickness question for small room

[soundthinker]

vass-

I'm working with very similar room dimensions in a video edit suite and have similar questions. The primary and secondary room-modes are 69, 81, 57 and 138, 161, 114Hz and the editor faces into a corner - with a 36"x36" glass window immediately to the left.

My plan is to use 4" thick 703 straddling the front and rear wall-ceiling corners but I'm concerned with how far the 4" panels on the walls stick out into this already small-feeling room. How much am I compromising by using 2" thick panels for the lateral first reflection points? I would also take them out of the frame and bevel the edges which leads me to wanting to use a denser panel for more durability.

I'm eager to see what the other forum members think. I'll be searching for relevant posts in the meantime.

-Jim

PS: This is my first attempt at posting an image. Let me know if I should resize it.

[n0nspaz]

Hi I am a novice but i will chime in here. maybe you can learn from my experience.
i treated a large basement studio with tons of unfaced, framed, white linen covered 2" 703&705 panels. across all the corners, on walls with 2" gap, clouds, etc. all over the room. the room had DIED. not that there ever was anything pleasing to speak of. take this approach and you will kill all of the high end and create the sound of a giant clothes closet.

that said i have no idea what to do with your small room there. they say absorption is best. from what i have read (like realtraps.com) i suggest- think 1. BASS absorption is job #1, and 2. treat one of each parallel wall to reduce reflections while minimizing the# of absorbers. e.g. fill up the corners with hard-front or FRK foil absorbers and pink insulation behind (retains highs) (or choose a pre fab bass trap for all possible corners). also choose carpet OR clouds not both

i am just repeating what i have read here from those more experienced, and what makes sense to me. best of luck to you

[avare]

Many people, including myself, recommend 8" total thickness panels for first reflection points as a minimum. That thickness could be 4" of 64 kg/m³ mineral wool with 4" airgap, or 8" of 32-48 kg/m³ material.

Andre

[vass]

Thanks for the replies!

Avare, The 4" panel and 4" gap was what i was aiming for but with 100kg/m2. Would that be too much density in your opinion?

Also, touching on what n0nspaz said would covering first reflections in that maner (which i will definately be doing) AND placing panels on the front and back walls with the same method potentially be too much?

Obviously for bass in such a small room it will be beneficial and i will obviously have to compromise soewhere... would losing some livelyness in the room be worthwhile to control the bass response a bit more in your opinion?

Thanks again!

[DanDan]

100KG will be fine at 4 inches.
At least one source shows little difference in measured absorption in fibres with a 4:1 range of densities. Most of the commercial products use 100KG. Although more expensive it is much easier to work with.
Here's something from one of my very clever clients.
Best DIY Trap EVER

If you want some HF bounce in your room, consider adding wooden laths frontage on your SSC's.

DD