Many, many companies make straightforward sound absorber panels. These are often just called 'acoustic panels' and are equally useful in a home theater or stereo listening room. Acoustical panels are constructed with a compressed fiberglass / rockwool core (or other eco-friendly equivalent) and fabric covered. Acoustic panel fabric is generally open weave or perforated although more modern fabrics look like suede. The key is that air can pass through them to the core beneath. Most of the variation between manufacturers is in fabrics, colors and how the panel is made structurally. There are very few differences between the products in acoustical performance. In this blog post we review the product offerings from the major acoustic panel manufacturers. Absorptive panels are best used to control strong early reflections through a ceiling or wall placement, provide bass absorption and to reduce the overall reverberation time. The simplicity of manufacture means they are not the best choice for bass absorbing duties - membranes, panel and Helmholtz type absorbers offer greater absorption in the bass region. Often manufacturers label a panel a 'Bass Trap' if it is over 4" in depth...but in reality it is just an acoustic panel using more compressed fiberglass! If used excessively straightforward absorber panels can also result in an overly 'dead' room which has a low reverberation time, creating an environment that makes listening to music and watching movies uncomfortable. Here is a list of the main manufacturers and some comments about each:

• RPG's Absorber panels are the panels of choice for Acoustic Frontiers. They come with resin hardened edges and are available in over 80 fabric choices. The Anchorage fabric finishes look 'furniture grade' and integrate extremely well into different rooms. The edges of the panels are available beveled or mitered, which means the panel looks visually smaller than those with a square edge. Visit our shop now to see the full range.
• G&S (Golterman & Sabo) are the only manufacturer of custom painted absorber panels that we know of. Available in over 1,500 different colors (yes, you did read that right), they are the choice for high-end rooms where aesthetics and color matching is important. Acoustic Frontiers is a G&S reseller, so contact us with inquiries!
• Primacoustic, another one of the companies we represent (see here for their range), offer the Broadway series of panels. Available in three colors they also come in multi-packs of 4 which reduces cost significantly.
• GIK Acoustics have a number of panels (e.g. the 242, 244, Monster Bass Trap) that have a wooden frame with a fabric covering. The wood makes the panel heavy but includes a small airspace on the back which does slightly increase absorption. Available in a 6 standard colors with an upcharge for additional fabrics. The larger panels are definitely visually 'intrusive'.
• ReadyAcoustics Chamelon series (C2, Bass Trap, Super Sub Bass Trap, Ceiling) have a metal frame with a fabric 'bag' enclosing the fiberglass panel. Available in a moderate number of colors.
• ATS Acoustic Panels and Bass Traps have a wood internal frame and back panel with jute fabrics.

In our books any manufacturer needs to produce acoustic panels that provide constant absorption (or a sound coefficient of 1) down to the room's 'transition frequency'. The transition frequency is where the room's frequency response becomes dominated by the effect of modal resonances. We typically use the figure of 250Hz as being a good rule of thumb for the transition frequency. For the vast majority of manufacturers this means having a minimum of 3" thickness of panel core. 2" can be effective if combined with an airspace but 1" is not a thickness that is of any use in a high end stereo or home theater situation. See the explanatory text at the bottom of this page for more information. Do you know of any other panel manufacturers we should add to this list? If so please leave a comment!