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Published On: March 5, 2021Tags: ,

ASC’s AcousticSoffit: Wall Panel, Bass Trap, and Lateral Diffuser in One!

Some audio playback rooms can really benefit from bass traps in the high-pressure corners. No, wait, ALL audio playback rooms sound better with bass traps in the corners.

Let’s try again: some audio playback rooms can really benefit from treble range absorbers to control early reflections. No, wait, we are still talking about ALL high performance audio rooms.

home theater with acoustic soffit along ceiling perimeterOne more time: some audio playback rooms that are occupied by humans with two ears can really benefit from low-level lateral diffusion in the upper treble range. Darn, still not quite right! ALL rooms with people sound better when lateral diffusion exists.

Does a magical, mythical, legendary device exist that delivers all these benefits? Of course, and it is a TubeTrap. But unfortunately, TubeTraps do not fit into every room decor, nor is the corner floor place always available.

Enter: the ASC AcousticSoffit! Check out some of the system options here, and keep reading for more details about this unique all-in-one room solution that works in HiFi rooms, Studios, and Home Theaters alike!

Function #1: Clean up the Muddy and Boomy Bass!

broh power washing mud off his black jeep Cherokee with roofrack

Like a TubeTrap, the AcousticSoffit operates as a lumped parameter acoustic circuit in the bass range. The RC time constant controlled by the flow-resistive exterior and the capacative air interior determines the low frequency extension of the unit. To get an idea of the deep bass absorption capabilities of this little powerhouse, the specific R/C values used in the AcousticSoffit are comparable to those of a 24″ diameter TubeTrap!

RC diagram

hifi room with towertraps acoustic soffit soundplanksDevices like this operate most efficiently in the corners of the room, hence the installation of AcousticSoffit along the entire wall-ceiling perimeter, where possible. Tight, accurate bass can be yours without losing an inch of floor space. Think of it as a massive installation of 24″ model QuarterRound TubeTraps–at a fraction of the cost!

Plus you get a nice, clean, square look. The TowerTraps in the corners really compliment the system.

Function #2: Control the Early Reflections

Many people are inclined to focus on the mid-height of the walls, using mirrors to see the tweeter reflection points in their attempts to control early sidewall reflections. This is fair, understandable, and usually quite effective. But what about those other early reflections, that bounce from the wall to ceiling then back at your ears? Or from ceiling to wall and back to your ears? Repeat this for the floor, and we have a veritable slew of strong specular, very early reflections being ignored that contribute to image smearing and upper treble harshness.

audio reflections from sidewall illustration

You may recall the concept of “acoustic shadowing” from our discussion of AttackWalls and QuickSoundFields. But don’t forget these shadows are cast by many objects, all over the room, and sound bounces around at 770 miles per hour. Every shadow counts, and the AcousticSoffit casts a large shadow on both the walls and the ceiling to which is is adjacent. This effectively intercepts incident sound waves and prevents their return to your listening position.

audio reflections from sidewall illustration with acoustic soffit

This renders the system acoustically equivalent to a wall panel of approximately 5 feet length, and provides the same degree of improvement to imaging and treble clarity.

audio reflections from sidewall illustration with shadow zone

No wonder many AcousticSoffit owners opt against installing classic mid-wall panels after completing their soffit installation; the benefits are already there!

Function #3: Provide Lateral Treble Diffusion

dark night winter scene snow crescent moon pine trees covered in snow

Some call it “ambience,” others call it “spaciousness,” similar to “air” or “sparkle.” Whatever your preference, this is a dish best served sideways–that is, the diffuse treble range sound energy is most pleasing when traveling across the room rather than along the length. Read more here.

Why sideways? As mentioned, people have stereo hearing with two ears separated laterally. Subtle timing differences between sounds arriving at either ear tell us the direction of a sound source and the size of the space we are in. Of course, this psychoacoustic perception can be scrambled by strong early reflections, hence the use of wall panels and acoustic shadow devices (see previous section).

In order to provide lateral scattering of sound, every AcousticSoffit is fitted with an alternating pattern of absorption and reflection across the face that is perpendicular to the room walls.

acoustic soffit blueprint with treble reflector and absorbers

Seen below is an overhead view of an incident sound wave striking such a surface. The waves are shown as rays for ease of explanation.

illustration showing sound absorption and reflection from wall

A portion of the incident wave is reflected in a specular manner (red line with arrow) and a portion of the incident wave is fully absorbed (green line). However, a significant portion of the incident wave is diffracted at the edge of the reflective element due to the change of impedance. This bending of the wave causes the reflected portion to scatter and weaken, maintaining phase coherence. We call this “specular diffusion.”

What is the practical effect of this feature of the soffit? It keeps your room from sounding “dead” by providing a soft yet bright overhead ambience that causes your room to sound big without feeling cavernous.

OK, I Love it! How do I Get it?

We’re so happy you asked! To achieve proper fit your room, accurate measurements are needed along the wall segments to be treated with AcousticSoffits. Our technicians then help decide on a typical segment width for your wall(s) and figure out how many pieces are needed. After construction and installation of all but (1) last piece, you provide us the final measured dimension and we construct the final “keystone” segment.

Installation involves attaching a PVC railing to your wall and ceiling into which the AcousticSoffit segments fit. Most people are able to perform this installation themselves using a pencil, cordless drill, and step ladder. Everything else is included!

The system is easily expanded upon, allowing users to complete one section of the room at a time. Customization options are also bountiful, including but not limited to: lighting, projector windows, HVAC routing, custom depths/heights, and mid-room termination points.

Standard segments protrude 10″ down from the ceiling and stick out 16″ from the wall. Each segment is usually 24″ wide. Plan on about $120 per linear foot of AcousticSoffit in your room.

This AcousticSoffit provides excellent rear wall control in a high-end Home Theater.

This mixing/mastering studio used AcousticSoffit to control the upper corners in the head end. Described by Chips Davis as "the best sounding small studio I've heard.

Vicariously experience one of the finest listening rooms you will ever see. Check out what shows up at the 7 minute mark!

The ASC AcousticSoffit: Tight, Accurate Bass with unparalleled overhead ambience

What is the best acoustic treatment I can get?

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