Because You Need To Know The Truth About Pistonic Driver Cones …
Bringing paper cones to a super-speaker today is like bringing a horse and buggy to a Formula One race. Materials and performance have evolved and so must loudspeakers, especially at the high-price super-speaker level. Crucial to avoiding performance-killing distortion in loudspeakers are driver cones rigid enough to remain pistonic throughout their pass band, i.e., the range of frequencies each driver is required to reproduce.
“Pistonic” refers to the motion of the driver cone in response to the audio signal from the driver’s voice coil. If the driver cone stays rigid and moves in and out in truly pistonic fashion, distortion is avoided and the purest replica possible of the signal from the amplifer is produced by the speaker. If any part of the cone flexes or bends in the opposite direction of the signal, part of the cone is out of phase, and distortion is output from the loudspeaker.
In the dramatic video above, Richard Vandersteen talks through a comparison of two midrange driver cones using highly advanced imagery from a Klippel analysis. Klippel allows us to see the cones’ behavior in response to audio signals in real time and evaluate their performance. One cone is Vandersteen Audio’s “Perfect-Piston™” midrange cone, which is a patented ultra-rigid carbon-fiber/balsa core design. The other is a very expensive paper driver cone that is employed in some very high-end speaker designs …
This Is Your Driver Cone On Paper …
What’s truly shocking in this video is that so much audible distortion is readily visible at 1.4kHz with approximately half of the paper cone flexing out of phase. 1.4kHz is of course well within the crucial midrange frequencies this driver cone would be expected to reproduce in any speaker design. This range comprises so much of the soul of the music we love, and the sad truth is that this midrange cone is incapable of faithfully reproducing music in this critical band.
The video shows too that the paper cone is in complete chaos at 5kHz, the middle of the “presence region” of the frequency spectrum. The presence region is above the midrange but well within the overlap region where the midrange driver transitions to a tweeter. This range has a distinct effect on vocals and instruments, as recording and mixing engineers are very aware of.
The types of gross distortions demonstrated in this video are audible not only as a loss of resolution, but also as noise and dynamic compression. When the driver cone motion becomes chaotic, sounds are still produced in the areas of the cone that are in “breakup mode.” But those sounds aren’t related to the musical signal. Sound you can hear that bears no relation to the signal is pure distortion. Or, in a word, just noise. And the paper midrange in the video is producing a LOT of it.
The paper cone distortions demonstrated in the video also soften transient impact and blunt dynamic peaks. Loudspeakers simply cannot deliver full dynamic range when large portions of the driver cones are not moving with the signal in pistonic fashion. The orchestra can no longer play at full power when the loudspeaker’s driver cones are in “break-up mode” and the cone’s motion is chaotic.
Speaker distortions such as these are often explained away as sins of omission. In fact the “lossy” nature of these distortions might smear enough musical information to hide flaws in other components in an audio system. While speakers with paper cones exhibit compromised dynamics, they can often be played VERY loud which fools less experienced listeners into believing they are hearing real dynamic range. But all distortion factors increase as the volume goes up, especially in power amplifiers. There is no free lunch.
These may be acceptable compromises in entry level or mid-fi systems. At Vandersteen Audio, we see no reason on earth to accept compromises like these in statement loudspeakers at high prices.
Vandersteen Audio customers have always demanded more and so has Richard Vandersteen. Richard spent a decade on the R&D that led to Vandersteen’s patented Perfect-Piston carbon-fiber/balsa core driver cones, shown in the video to be truly pistonic and unflappable.
Vandersteen’s Perfect-Piston driver cones are handmade in Vandersteen’s California factory. They debuted in the Model Seven in 2009 and are still used in the Model Seven Mk II, Vandersteen’s current flagship. Driver cones descended directly from these amazing designs are also featured in Vandersteen’s Model 5A Carbon (Carbon Midrange and Tweeter), Quatro Wood CT (Carbon Tweeter), and Treo CT loudspeakers. For home theater enthusiasts, CT versions of the Vandersteen’s VCC-5 center channel and VSM surrounds are coming soon.
The video here dramatically demonstrates the distortion-free pistonic performance of these incredible drivers over a wide range of frequencies. It is not a coincidence that the Model Seven and Seven Mk II are on an unprecedented tear of great press and “Best of Show” accolades that is nearing a decade in duration. Other brands merely claim state-of-the-art components and performance. Vandersteen Audio proves it.