Johns Standard Control Room

[JohnH]

I have the rear ceiling soffit absorber partially installed and wow, what a difference in the bass.
I post photos and FFT data soon.

PS: Noahs 2nd flood has receded for now. What's next, locust?

[JohnH]

Glenn,

I finished the ceiling soffit today except for the final trim.
I might as well get ready to build the cloud(s) while waiting for the 703.
Many posts back you showed an angled cloud over the mix position, and parallel cloud in the back.
What are the design details for the clouds I should make?

[gullfo]

maybe something like this? you could use solid backing and make the absorption to the edges.

[JohnH]

Very nice looking!

If I have studied well, the plastic is to keep fiberglass particles from dropping down, also adds a little high frequency reflection.

Two questions:
1. Does the plastic go only on the bottom face, or around the exposed edges too?
2. What holds the 703 in? Press fit into the 1x1 frame or glued to the plywood?

Any other construction hints particularly about the fabric / 703 attachment and frame would be appreciated.

Thanks again Glenn!

John

[gullfo]

plastic on the face, press fit into frame, cloth on outside of frame.

[JohnH]

Back from vacation and ready to continue the project.
The OC 703 is supposed to be in and I'm trying to pick out fabrics.

Glenn, I have some questions about the clouds.

Cloud positioning: (edit) I have a track lighting unit right over my mix desk 5'-8" from the front wall) running parallel with the desk. Will the clouds work optimally with the track light located in the 6" gap between the front and rear sets of clouds? Any adjustment is needed?

Regarding cloud size: On the larger cloud units, the size (2'-7.75" x 5' ) makes for a lot of waste with a 4'x8' sheet of plywood. Also 703 comes in 2x4 sheets. What's the thinking here?

Thanks

[gullfo]

unless you buy sheets in 3'x5' (and just go with that)... the 3x5 then leaves around 6" all around the edges. you could leave a slight gap for the track lights or even suspend them down between the clouds.

[JohnH]

3'x5' sheets of plywood are new to me.
What type should I be asking the lumber yard for?

[gullfo]

3/4" interior finished grade A-B or A-D plywood. if they don't carry it in 3x5 (or 30"x60") let me know and we can resize the clouds a bit to use what is available efficiently.

[JohnH]

I tried. Can't get 3'x'5' plywood. Only 4'x8' Unless special order.
So resizing would be my choice.

[gullfo]

maybe go with 2'8 width (3 cuts per 8' sheet). front row is angled 22.5 degrees (or so) and back row 12 degrees (or so). this should cover most of the width of your room and back to almost the middle.

[JohnH]

Thanks Glenn,

The 703 just came last week and I purchased some decorative fabrics to cover all the treatments. We're scheduled to start building the clouds and sidewall absorbers next week.

One question: Why slotted plywood vs. an open back?

[gullfo]

mass. the angles and mass are disruptive. an open back is simply absorptive and might not be as effective.

[JohnH]

mass. the angles and mass are disruptive. an open back is simply absorptive and might not be as effective.

Ok. How about for side wall absorbers? I was planning on 4" thick, open back spaced an 1" or so away from the wall.
The typical broadband absorber that everyone builds with coeficients around 0.9 in all freq bands (according to the charts)

[gullfo]

the proximity of the wall to the open back on the side absorbers will provide the reflection function (and the walls are already disruptive )