DeVore Fidelity Silverback Reference loudspeaker Manufacturer's Comment
Editor: I'd like to thank Michael Fremer for his impressively thorough and insightful review of our flagship speaker. We had a feeling a true music-lover like Mr. Fremer would have fun with the Silverback, but he really dove in and "saw" the true nature of the Silverback Reference. We couldn't be happier with the review unless, of course, he had reviewed them before the big Wilsons. :^)
We'd like to assure current owners of the Silverback Reference that no change has been made to the speaker since its official debut at the Home Entertainment show in May 2004. The pair shown three months earlier in Las Vegas were preproduction samples that differed only cosmetically from the current model.
As Michael points out, I had some concerns about how the measurements of the Silverback Reference would be interpreted. The speaker was conceived, designed, and built with a very different approach from that of a Wilson or Rockport. The difference is most obvious in the lower frequencies, as John Atkinson discovered.
Bass is radiated from the entire lower two-thirds of the SB/R speaker in different ways, using tuned chambers and panels, ports, and the drivers themselves (both woofers and mid) to energize the room much as a large, low-frequency instrument would. With this technique, individual elements work in concert and therefore aren't pushed as hard to create a given amount of energy. Our measurements of the individual drivers and ports look much like JA's (well, maybe a little smoother), but when cabinet and room contributions are added, things do look better.
John is correct in pointing out that it's easier to set up big, full-range, reference-level speakers in a larger room. Michael's room seemed too small when I first arrived, with the speakers only 7–8' away from the listening position, but it is a great-sounding room. Its size, however, does limit placement options. During initial setup I found two speaker positions I liked: one with more upper-bass power, and one with more overall coherence and integration. The two positions were within a few inches of each other. I explained the difference to Michael and left them in the second spot, which I preferred. A larger room will have more options for combining the two strengths.
John's measurement plots of the mid and treble regions are very accurate when measured (as he did) from the tweeter axis. The proper listening axis, however, is about halfway between the midrange phase-plug and the top of the cabinet. In Michael's listening room (and most others), this means adjusting the rake angle of the speakers so they actually tip forward, toward the listener. (I assure you, Mikey was never in any danger.) You can see this in JA's in-room graph (fig.9). A fairly true picture of the on-axis response is available by combining elements from fig.8 and fig.5. The best listening axis is about 10° higher than that measured in fig.5. That axis roughly corresponds to the curve second from the rear in fig.8. This curve develops a suckout (at just below 5kHz) that corresponds exactly in frequency and magnitude to a peak in fig.5. The same goes for the peak at around 8.5kHz. The SB/R is intended to be very flat in this band at the correct listening axis (see fig.A). As MF noted and JA verified, setup is very critical here. The manual recommends that, when you're seated in the listening chair, your eyes should be level with the top of the speaker cabinets, which places your ears on an axis an inch or two below that. This also neatly lines up the tweeter and midrange-driver step responses, eliminating the slight offset seen in fig.10.
Fig.A DeVore Silverback Reference, response on tweeter axis (orange) and on listening axis (blue).
Again, we want to thank Michael and John for making this review happen, and for their professionalism and keen observations of the 100-lb gorillas in their midst.—John DeVore, President & Chief Designer, DeVore Fidelity