Designed for low frequency absorption below the range of conventional porous panels, our 9" Diaphragm Bass Traps are predicted to work from about 80 Hz up on 2 ft wide panels and about 60 Hz up on 3 ft and wider. Specify them where modal buildup and low frequency decay are the limiting problem and a 4" panel has run out of depth.
For a single booming note below that, add a tuned Membrane Bass Trap behind it or beside it.
Sound passes through the fabric face and 8-1/4" of 2.5 PCF mineral wool and drives a single-piece ¼" plywood diaphragm mounted on the back of the frame. The mass of the diaphragm and the flow resistance of the fill together extend absorption well below what a porous panel alone will reach, and unlike a tuned membrane trap, absorption continues across the mids and highs above that point. Built on a plywood frame with internal bracing, filled solid so the insulation rests against the diaphragm, and wrapped in fire-rated fabric. The diaphragm is cut from a single sheet and mounted so it remains free to vibrate.
Finished in your choice of 50 acoustically transparent colors in Guilford of Maine Anchorage 2335. Choose the aluminum Z-bar cleat wall mount kit, floor legs, or floor legs with locking casters.
Absorption
Predicted to work from about 80 Hz up (2 ft wide) and about 60 Hz up (3 ft and wider) when wall mounted on the standard 1/2" spacer strips, with absorption continuing across the mids and highs. Click either graph to see it full size.
Next to our Membrane Bass Traps, which each take out one low note and absorb almost nothing above it:
Face Options
Full Range: Fabric over the open insulation face, for maximum absorption across the full range.
Low Reflection: A finely perforated hardboard sheet behind the fabric, 3/16" holes on 1/2" centers, about 10% open. It absorbs through the mids and gives back part of the top octave, from about 2 kHz up. For control rooms that sound a little too dead up top.
Medium Reflection: A perforated hardboard sheet sits behind the fabric. The holes pass the bass and low mids through to the fill behind it. From about 800 Hz up, the solid hardboard between the holes sends a growing share of the sound back into the room, so a room treated with several of these keeps an open top end instead of sounding over-deadened.
High Reflection: Alternating 6" strips of perforated and solid hardboard behind the fabric, about 2.5% open. The bass still passes through to the fill, and from about 450 Hz up most of the sound goes back into the room. For tracking and live rooms.
Every plate sits under the fabric, so the panel looks the same from the front, and adds ¼" to the depth (9-½" overall). Plate performance figures are predicted.
Legs and Locking Casters
Choose floor legs in place of the wall mount kit to stand this panel anywhere in the room, or floor legs with locking casters to roll it. Click either photo to see it full size.
On floor legs with locking castersLeg and caster close-up
Leg Orientation: Two solid Douglas fir legs, 17" long, run front to back under the panel and stick out about 4" past the front and the back. On 2' wide panels they sit 2" in from each side; on 3' and wider, 5" in.
Locking Casters: A set of four black swivel casters with 2" polyurethane wheels, one bolted under each end of each leg. Each caster has a foot brake; lock two and the panel stays where you put it. Casters add 2.75" to the overall height.
Wall Mounting and the Air Gap
The diaphragm on the back of this panel needs open air behind it to work. Panels ordered for wall mounting ship with plywood spacer strips fitted across the top and bottom of the back. The Z-bar cleats mount to those strips, which holds the diaphragm clear of the wall. Wall cleats must be screwed into studs. Two people are needed to lift.
Panels ordered on floor legs ship without the wall mount kit or spacer strips. The legs extend about 4" past the back of the panel and keep the gap on their own.
Effective Range: Predicted from about 80 Hz up (2 ft wide), about 60 Hz up (3 ft and wider)
Frame: Plywood, internally braced
Depth: 9-¼" overall: 9" frame plus the ¼" rear diaphragm. 9-½" with a reflection plate
Fabric: Guilford of Maine Anchorage 2335, in 50 acoustically transparent colors
Mounting: Z-bar cleat wall mount kit with shop-fitted spacer strips, floor legs, or floor legs with locking casters
Ordering and Shipping
Custom made. Ships by freight, with the rate calculated at checkout. Very large orders get a freight quote, which we'll email you for approval before we start your build. Local pickup and local delivery with installation are also available.
Available in 50 Fabric Colors
Every panel is wrapped in Guilford of Maine Anchorage 2335, in any of 50 colors.
