John Sayers' Recording Studio Design Forum Archive

Riad · Post by **Riad** » Wed Apr 14, 2004 12:00 am

The footings for the slot are there, however, it hasn't been built yet. I'll use MDF board every two feet to create a box between the angled footing and the rear wall. I'll put Roxul AFB in between the MDF then cover the whole resonator with fabric. I have 1" thick pine up to 6" wide for the slats that I can then rip down to different widths as needed.

I don't have a detail drawing of this but I plan to stick as close to John's design as possible. I'll try to use the spreadsheet to calculate the slat width and spaces.

The rear low absorbers will be 2x4 framed with Roxul AFB and fabric.

The rest of the walls are 703 where indicated.

The live room will mostly diffuse, there will be a drum kit in there as well, with some absorption.

That's what I'm thinking so far.

knightfly · Post by **knightfly** » Thu Apr 15, 2004 9:50 am

OK, so you're planning on separating the space behind the slats into 2 foot separate absorbers?

Also, what are the dimensions of your rear absorber - depth, width, height, angles, etc - if there's room, some hangers would really enhance the effect... Steve

Riad · Post by **Riad** » Thu Apr 15, 2004 10:36 am

knightfly wrote:OK, so you're planning on separating the space behind the slats into 2 foot separate absorbers?

Also, what are the dimensions of your rear absorber - depth, width, height, angles, etc - if there's room, some hangers would really enhance the effect... Steve

I was planning on separating the space into 2 foot absorbers, is that a problem?

I was thinking of creating the rear absorbers to hang - 2x6 wood frame with Roxul covered in fabric. I was planning on leaving about 6" from the rear wall so that the absorber does not touch the wall.

Thanks,
Rob

knightfly · Post by **knightfly** » Fri Apr 16, 2004 12:41 am

No problem at all, in fact preferable - if you seal the slot into 2 foot sections, then you'll get more effect from the differing depth from section to section, which will help smooth out the response more - each section can be tuned differently that way. If you were to put the slats on vertically, you could even vary the slot width per 2' section, possibly treating several modal peaks -

As to your rear absorber depth, I was wondering if you had enough room to place hangers in a "herringbone" pattern, with extra damping layers - Newell does a thing with a multi-stage rear wall that almost completely disappears acoustically, but it takes between 2 and 3 feet to pull off.

IF you don't have that much space (or enthusiasm) your way will work as good as anything in that amount of space... Steve

Riad · Post by **Riad** » Fri Apr 16, 2004 11:45 am

Thanks Steve, I'll evaluate how much room I have. Don't think I have 3 feet to spare so I might have to go with plan A, but it's really good to know.

I'll take more photos of the construction as it comes along.

Thanks again,
Rob

Riad · Post by **Riad** » Sun Apr 18, 2004 3:46 pm

knightfly wrote:If you were to put the slats on vertically, you could even vary the slot width per 2' section, possibly treating several modal peaks -

Have you seen anyone put the slots on a track so they can be moved? If I was to vertically hang the slats with the upper and lower ends mounted on a track I could adjust the slats to fine tune the room.

knightfly · Post by **knightfly** » Sun Apr 18, 2004 6:14 pm

Not a bad idea, but I'm not sure how it could be accomplished - the slats need to be tight against the backing cloth and locked down so they don't vibrate against their mounts - they also need to be sealed so that the only path into the cavity is through the cloth between the slats - if you can figure out how to accomplish that and keep things adjustable, let me know... Steve

piginzen · Post by **piginzen** » Mon Apr 19, 2004 12:58 am

does anyone know a good place to purchase the 703?

home depot?

knightfly · Post by **knightfly** » Mon Apr 19, 2004 1:45 am

No Home Depot I've ever been in - all they carry is foam insulation (closed cell, worse than nothing for sound) and the pink fluffy stuff.

You can check the materials forum on this site, may find DC sources - other than that, the way everyone does it is to call each and every insulation contractor in the local yellow pages til you find one that (a) carries or uses rigid fiberglas, doesn't matter what brand (Owens Corning, Knauf, Johns Manville CertainTeed mainly) and, (b) will sell to you. Don't get discouraged if the first 10-12 won't talk to you, sooner or later one will.

If you find one that way, please post your info in the materials section so others can benefit - that's a lot of what this site is about... Steve

piginzen · Post by **piginzen** » Mon Apr 19, 2004 4:05 am

Yeah. I am on it!

And i'll post my findings here!

Thanks,
mat