Todd E. Jones's Ceiling Diffusor, Ceiling and Wall Traps, and Corner Traps

From his website

Bass Traping Philosophy
After much research into studio design, much of it baffling and bordering on black magic, I have concluded that bass absorption is critical, especially given my stucco'ed cinderblock walls. Rather than choose a single bass trapping approach, such as panel traps or Helmholz resonators, I have decided to employ several different systems. My theory is that by deploying different technologies, I will more or less compensate for the deficiencies in any one approach as well as deficiencies in my construction techniques.

Below is a series of thumbnails leading to big pix of these bass traps...

The Ceiling Diffusor!

This is my attempt to negate at least one set of parallel surfaces, while also putting a bass trap in place without taking any precious floor real estate. The ceiling is cathedral, but with a 3 foot section that houses the trusses and is parallel to the floor. On either side of the angle which turns down toward the floor, I have installed rails in the ceiling. These rails have been angle cut to comfortably accomodate the arc of plywood.

The plywood is 1/4" which bends with some coaxing. My wife helped me bend it into its rails. It popped right in! Then I plugged the end and caulked to ensure airtightness. I stuffed the cavity with leftover R-19 insulation. I built a second one, yielding a resonant cavity that is about 14 feet long, 40 inches wide and about 12" deep at its deepest bend.

I have yet to crank anything up yet, but I could swear I already hear the difference.

Another view of the ceiling mounted diffusor.
Here you can see inside the diffusor to the far unit which is filled with insulation, as will be the one in the foreground shortly.

View from the loft. You can see the diffusor in the ceiling. The scaffolding is roughly where the mixing position will be.

 Ceiling mounted hooks. They are 5/8" diameter and go deep into the joists. Still not sure what I'll hang (clouds, lighting frame, etc...), but I thought I'd put 'em in while I know where the joists still are.
Ceiling absorption is provided by 2" panels of 2' X 4' OC703. It is wrapped in breathable fabric and mounted on 2X2s to offset it from the sheetrock of the ceiling. Here's a closeup of the offset from the ceiling...
Here's one of the frames (a 2' X 4') for mounting on the wall. I found it much easier to build the frame first, then mount in on the wall second. Here's a frame that's been mounted on the wall. There is lots of silicon based caulk to ensure it has an airtight seal against the wall.
Once mounted, we put the OC703 into the frame using screws and big ol' fender washers into the 2" X 2" internal framing. Here are 3 bass traps, two waiting for their stuffin'
Here's the left absorptive bass trap. It is a series of 2 back to back panels of 2" OC703 stacked upon each other with a triangular air space behind them in the corner. This yields 40 square feet of 4" OC703 with a corner air space that varies from 2' deep to flush. Here's the right side with its complement of 40 square feet of 4" OC703 absorption.
Here's the view of the mix position from the loft above. Yes, there will be a heavy curtain to draw in front of the window. Here's a view of the corner which features an odd assortment of bass handling stuff.