Johns Standard Control Room

[JohnH]

Glenn, I've searched and searched but could not find the FitZ posts you mentioned, but I get the idea.
I prefer not to make built in bass traps....attached to the room....yet...not ruling it out..probably need em.
BUT free standing, movable (even tunable bass traps?) acoustic treatments would be a very appealing idea.
Not attached - not taxed year after year (cheap bastard)
If I move, I can take them with me or sell them.
(Red neck shed with wheels on it)

Since storage is important to me, I'd like to talk more about the "sound absorbing wall unit" idea.

Here's a concept picture.

Sound Absorbing Shelving.png

I'd like to build 3 or 4 of these and place them across the entire back wall.
The center unit might have a small built in desk.
Any thoughts on design details?
Material? Depth 12 inch? 15 inch? Trap inner workings?
Am I nuts?

Also here are the latest photos.

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[gullfo]

berry berry nice!

on the cabinets - maybe line the back of the slats with 2" cloth covered absorber and leave about 3/4" openings - perhaps a slot panel made from plywood and/or hardwood. on the tops - i'd still consider the soffit approach if only across the top of back room - 12"-14" down from ceiling and 3' - 4' deep or so.

[JohnH]

So build that soffit all across the back wall, up under the ceiling....
and forget about aborbers in the upper cabinets?

[JohnH]

on the cabinets - maybe line the back of the slats with 2" cloth covered absorber and leave about 3/4" openings - perhaps a slot panel made from plywood and/or hardwood. -

I'm not getting a clear picture on the bottom cabinets.
Do you mean to put the 2" cloth covered 703 or 705 immediately right behind the doors?
Or all the way back of the cabinet?
3/4" inch gaps between the slats?
Is this going to be a Helmholtz (slat) resonator?
Can I still use the cabinets for storage?

[gullfo]

something like this? maybe angle the fronts a bit so they're not flat. if sealed all around, you will definitely get some HH absorption but you might consider lining the shelves with some anti-slip pads to secure things stored there and avoid rattles.

[JohnH]

Glennnnnnnnnn! Way cool looking!!! Thank you!!!

Doors angled for diffusion. Hard surface to reflect the highs and some perforation to let some sound in.

The cabinet backs are open? Or should they be sealed?

Can you shed some light on the design parameters for tweaking the frequency response?

Is it a Slat Type Helmholtz Resonator or something else?

[gullfo]

the cabinet could be sealed to the wall. it's sort of a HH but not strictly - it's more like one of John Sayer's wall units with opening doors and shelves... as for the slat/slots 1/2" - 3/4" slots spaced (in this example like a QRD 17 pattern) as you like. better yet run REW to see what the room is doing and make the units more specific to any frequencies that need to be targeted.

[JohnH]

it's sort of a HH but not strictly - it's more like one of John Sayer's wall units with opening doors and shelves... as for the slat/slots 1/2" - 3/4" slots spaced (in this example like a QRD 17 pattern) as you like. better yet run REW to see what the room is doing and make the units more specific to any frequencies that need to be targeted.

What's an "HH". (The search feature on this website rejects 2 letter searches.)

[JohnH]

it's sort of a HH but not strictly - it's more like one of John Sayer's wall units with opening doors and shelves... as for the slat/slots 1/2" - 3/4" slots spaced (in this example like a QRD 17 pattern) as you like. better yet run REW to see what the room is doing and make the units more specific to any frequencies that need to be targeted.

I have downloaded REW (Room EQ Wizard)

I have two but questions Master....

1. What is an "HH" ? (I have searched long and hard for the answer throughout the entire world and even here, but he search feature on this website rejects 2 letter searches.)

2. Will the doors of the cabinets need to be tightly sealed when shut?

I await with infinite patience

[BriHar]

HH:
I think he means HELMHOLZ resonator.

[JohnH]

HH:
I think he means HELMHOLZ resonator.

HH = Helm-Holtz?........he happy having hyphenation hammered halfway in his nHame?

Sorry

[gullfo]

yes, Helmholtz do the doors need to be sealed? not really. they are much harder to open if they're sealed

[JohnH]

do the doors need to be sealed? not really. they are much harder to open if they're sealed

Well........I started it.

But seriously folks.......

All the explanations for a Helmholtz resonator use the bottle analogy....so doesn't the box need to be sealed everywhere except for obviously the slots?
If yes, gaskets would be needed around the doors?
If not why?

[gullfo]

if you want to seal it with gaskets you can to make it work more efficiently i'm ok with that...

[JohnH]

I guess, I don't just have a gut level understanding of how these slot resonators actually work.
Mechanical systems are much easier to visualize.

I done some research but its still not making sense.

Does each slot work independently like it's own beer bottle with one particular natural frequency?

Why are the slots at different spacing?