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Positive Feedback ISSUE 22
november/december 2005



Sound Panels

as reviewed by John Acton






ProAc Tablette Reference 8 Signature (primary) and Quad 11L l (secondary).

Bryston B60 SST and Audio Zone Amp-1 integrated amplifiers.

SimAudio Moon Nova CD player.

Analysis Plus Solo Crystal Oval interconnect (1 meter, RCA), Analysis Plus Oval 9 (bi-wire, 8 feet), Custom Power Cord Company HCF 2 Special (CD player), and Custom Power Cord Company HCF 2 (amp).

ASC Tube Traps in front corners (5 feet tall; 16" diameter) and ASC Studio Traps (2) behind equipment rack on front wall.


The amount of money we spend on our audio systems can range from merely costly to downright exorbitant, yet many of us neglect one of the most important components of all—the room—despite the fact that as our systems become more refined, room acoustics become all the more crucial. Acoustic Sciences Corporation (better known by the acronym ASC)s was founded in 1984 by Arthur M. Noxon, an acoustic engineer. While the company is best known for its patented Tube Trap product line, it manufactures a wide range of products and offers a comprehensive portfolio of consulting services for both professional and domestic applications.

The ASC Sound Panels control room reflections through a combination of absorption and diffusion. Sold in packages of eight, Sound Panels are designed to be affixed to walls and/or ceilings at primary and secondary reflection points. Each panel is 8 inches wide, 2 inches deep, and 48 inches tall, with an attractive half-inch beveled frame, and is lightweight enough to be hung by a single picture nail. The panels are covered with a cloth-like material, available in a myriad of colors to complement nearly any décor. Mine were finished to match my existing ASC Tube Traps and Studio Traps. The panels provide absorption down to 200Hz, blending that with diffusion above 400Hz.

A certain amount of experimentation with the placement of the panels is necessary to maximize their effectiveness, and if you have any questions, ASC's consultants can be very helpful. I achieved the best results by placing a Sound Panel behind each speaker and one in the middle of the front wall, with two panels on each of the side walls at the primary and secondary reflection points. The last panel was placed in an asymmetric corner on the back wall that is plagued by an especially pernicious reflection.

I heard improvements even before firing up the system. Just hearing myself speak demonstrated a new level of "quiet clarity." There was a reduction in slap echo and a more natural decay to my voice. I heard more benefits as I sat down to listen to music, and the best part was, no break-in (or warm-up) was required! From the first note, I heard improvements in clarity and resolution, coupled with a more relaxed and natural propagation of sound into the room. These were not subtle improvements. The reduction in room resonance allowed me to turn up the volume without causing fatigue. Low-level listening was also improved. Weather Report's Heavy Weather (Columbia CK 34418) is a bright CD, at least in the early mastering that I have, and the prominence of cymbal and percussion work can obscure inner detail. With the Sound Panels in place, there was no change in tonality, but because of the reduction of flutter echo and other spuriae, I was better able to listen through the brightness and hone in on the subtle interplay of Zawinul's ARP2600 synthesizer and acoustic piano on "Birdland." Likewise, Wayne Shorter's saxophone on "Harlequin" was better resolved, seeming to emerge from a haze that had been overlaying the soundstage.

Like their previous two releases, Clinic's latest CD, Winchester Cathedral (Domino DNO35CD) is musically excellent, but sonically, nothing short of a train wreck. Mastered at a ridiculously loud level, the CD is one of the most dynamically compressed I've ever heard. Couple this with a set of songs that sound like they were recorded in a public restroom with a Mr. Microphone, and the result can be painful. While nothing can truly save the sound of this CD, the ASC Sound Panels enabled me to hear deeper into the recording and focus on the musical message. With the Sound Panels, I could listen louder without feeling the need to run from the room or scramble for earplugs. On most songs, Ade Blackburn and Brian Campbell's vocals were still largely indecipherable, but I could discern more of their phrasing and tonality. On "Anne," I could clearly make out the lyrics, while the melodica and clarinet accompaniment sounded more natural. It was obvious that my untreated room had been exacerbating the flaws inherent in the recording.

What about better recordings? Traffic's Shoot Out at the Fantasy Factory can hardly be considered an audiophile recording, but after a Mobile Fidelity Sound Lab remastering (MFSL UDCD669), it sounds surprisingly good. With my room treated with Tube Traps, Studio Traps, and now Sound Panels, the sound of this recording made a solid leap forward in quality, from good to downright excellent. The new quiet of my room imparted a greater ease, warmth, and presence to Steve Winwood's voice on "Evening Blue" and "(Sometimes I Feel So) Uninspired." Chris Wood's saxophone on "Tragic Magic" was imbued with greater presence and tactility. With my room freed of anomalous echoes and midrange resonances, it was much easier to follow Wood's understated flute playing toward the end of the title track.

Imaging was more fleshed-out and dimensional with the Sound Panels in place. I heard a more spacious soundstage, with better width, height, and especially depth. Sounds were more divorced from the speakers. I also heard these effects on every recording. Once positioned, the Sound Panels reliably and consistently improved the performance of my system. Were there any downsides? I could not detect any. With any acoustical treatment, it is tempting to load up the room with product. More is better, right? Well, no. Too much absorption can suck the life out of a room. Fortunately, the ASC Sound Panels incorporate an element of diffusion in their design. Their blend of diffusion and absorption helps maintain tonal balance and ambience.

From an aesthetic standpoint, the viability of the Sound Panels will depend upon the room, the furnishings, and the listener's (and partner's) taste. While they are elegantly designed, they look somewhat utilitarian despite the myriad of colors available. This was not an issue for me, and the sonic gains more than outweighed the aesthetic considerations. Compared to the "carpeted trash can" look of the Tube Traps, the Sound Panels are downright sexy.

I've saved the best for last—the price. For $548, you get eight Sound Panels. That's less than a lot of audiophiles (myself included) spend on cables. Eight judiciously-placed Sound Panels are enough to treat a small to medium-sized room and render a huge improvement in the sound of your system. I have not come across any other product that has improved the performance of my system so fundamentally for this amount of money. I have become convinced that without addressing room acoustics, an audio system is not complete. Before you contemplate that next can't-live-without-it upgrade, you owe it to yourself to experience ASC's phenomenal Sound Panels. John Acton

Sound Panels
Retail: $548/package of eight 

Acoustic Sciences Corporation
web address: