A Matter Of Diffusion Page 6

But let me give you the good news first. Without the RPGs, the Waveforms had the upfront, grab-you-by-the-glands presence that lifted you from mid-hall to the conductor's platform. Music sounded zesty and sure-footed, an effect like that of a crack orchestra triumphantly returning from a long road trip to play a favorite old lollipop for eager hometown supporters. Bass was generous, lively, yet relatively free of overhang. Up to what I would guess to be 100dB or so, dynamic gradations were first-rate, harking back to those mammoth designs of the JBL era. (It turns out those 15" woofers issue from that very firm.) The Waveforms set up a nicely delineated lateral soundstage, receiving markdowns for a foreshortened and somewhat clouded front-to-back perspective. I quibbled with some lower-treble peakiness, caused, it later turned out, by a minor miscalculation in the crossover, and probably exacerbated by those side walls. Yet on balance the musical effect was one where the whole was greater than the sum of the parts. Here then were speakers for the sybarite looking for a rollicking good time from his music, and who will trade away some finesse to get it.

With the RPGs, however, the speakers sounded tidier but strangely less involving. The sound lost much of its spirit and hence its fun. Although I was more engaged acoustically---immersed in the soundfield, really---emotionally I was oddly disengaged. This effect was commented upon by other listeners who were not predisposed by Otvos (or me or my staff) to the Waveforms' "unsuitability" with the RPGs. The soundstage became larger and more credible, and even the lower-treble peak seemed to lose its edge, but these were "improvements" of an oddly unflattering type. After living with the Waveforms and RPGs for some months, I called "Dr. Diffusor" D'Antonio about it and he, too, was at a loss to account for the effect. Otvos could offer nothing more than the observation that the speakers were designed to be used in a fairly reflective living-room-type environment. But there you have it: a case where the untreated room "outperforms" the same room with the full RPG complement.

The Big Picture
Without question, the diffusors did more to upgrade the overall musical experience in the main soundroom than any previous mitigation measure, whether it happened to be installing 4'x8' Sonex sheets on the front and forward walls, standing Tube Traps in corners, or isolating all undriven speakers in the separate holding area. The reduction in sonic grundge, the exposure of previously obscured inner detail and interleavings, the marked sense of envelopment within a musical event, and the perception that the walls had been blown down all contributed to a heightened sense of involvement in the music-making.

The results obtained in the main soundroom were duplicated in a smaller adjacent soundroom as well. This room has a low ceiling and a somewhat unpleasant sound, mitigated (partially) by the installation a few years ago of Owens-Corning floor-to-ceiling acoustical wall material on the front wall. When the diffusors were "parked" in this room (during the times we were "A/B'ing" the main soundroom), the sound was transformed in ways consistent with my descriptions of the treated main room.

Final Thoughts and Remaining Questions
Because all of us audiophiles---consumers, retailers, manufacturers, critics---are accustomed to seeing audio "solutions" take the more familiar form of devices that can be set on a shelf, plugged in, auditioned, paid for, and carted home in the back seat of the car, there is a chance the diffusor may not get the real "hearing" it so richly deserves. During the course of my year-long evaluation, a prominent high-end firm informally introduced the diffusors to select dealers at Chicago CES. The feedback they got suggested that most audiophiles would not purchase anything as unwieldy, expensive, and aesthetically unflattering as the RPG units, despite clear-cut and often dramatic sonic improvements. I hope this pessimistic prediction proves untrue, for it seems unlikely we'll have much meaningful audio progress unless and until we deal with the fundamental acoustic limitations of the average listening room.