Bad Vibes! Page 2

How does all this relate to mechanical vibration? I believe progress in audio design has reached a point that demands serious attention to these and other subtle interactions---along with the more obvious variables---if we are to further reduce the "electronic" signature in reproduced music and move toward a more convincing re-creation of the real thing. This is true whether one is dealing within the electrical, mechanical, or acoustic arenas. From a practical standpoint, the time and frequency domains are alternate frames of reference, and most real progress in sound reproduction is being made by those designers who have a good understanding of the interplay of these realms.

Mechanical resonances may contribute to the spectral signatures of components both directly (in the case of transducing components) and through interaction with other nonlinearities. Vibrations, varying in magnitude from gross (cabinet resonances that can be felt in the fingertips) to tiny, sub-micron levels at subsonic frequencies, can negatively impact music playback through time- and frequency-domain disturbances. On a fundamental level, the issues of phase linearity and mechanical vibration are interrelated; unless properly addressed, each defines a limit to a system's resolution. Since timing and resonance issues are two sides of the same coin, an improvement in one area often effects an improvement in the other, resulting in a net gain in system transient performance.

So as hardware on both sides of the recording/playback chain becomes more refined, mechanisms such as low-level vibration grow increasingly important. Though at first glance it may seem that cheap, flimsy gear would be the primary beneficiary of good vibration control, and while in relative terms this may be so, products that have inherently better resolution due to superior electrical and mechanical design tend to show the greatest absolute profit from effective resonance reduction.

A Matter Of Scale
Perspective can be a difficult thing to convey when describing subtle changes that can lead to significant subjective effects. In our enthusiasm for newly discovered tweaks or ideas that bring favorable alterations to the sounds of our systems, it is all too easy to go overboard in describing their relative effects, in the process blurring the yardstick of merit by which we decide how to allocate our audio dollars. This tendency seems particularly prevalent with certain anti-resonance accessories simply because their effects run the gamut from the barely perceptible to the clearly obvious They can also vary widely from system to system. In fact, it was the rather dramatic experience of hearing the sonic effects of pneumatically isolating a turntable and---surprisingly---a digital transport with the Vibraplane that led to this report, lest the relative sonic impact of these systems be confused with that afforded by more traditional means of equipment support.

Before floating my source components with the Vibraplane, I was, like many of you, intimately familiar with the array of tonal changes afforded by various tuning devices. But by the time the stylus of my Lyra DaCapo cartridge had reached the inner groove of the first record played on my RPM-2 turntable after a Vibraplane had been installed beneath it, I had experienced a pronounced enhancement in the broadband resolution of my system that was very different in degree and quality from that offered by tonal manipulation alone. These benefits were turned out to be both predictable and repeatable with a variety of source components.

I rank an even, natural tonal balance---with the emphasis on balance---as one of the most critical factors in true high-end performance. (This is to be distinguished from simply highlighting one area of the spectrum over another just because it sounds "better.")

But I'm not anti-tweak. Creative experimentation has often led to real breakthroughs, even when the relationships of cause and effect are not well understood. Tonal alterations that make listening to a given system more enjoyable are perfectly fine in my book as long as the effect is not mistaken for, or promoted as, a de facto increase in fidelity. In my experience, those improvements which prove most fundamental and genuine tend to be consistent throughout the audible spectrum, conferring greater cohesiveness, refinement, and presence to the entire presentation.

Tonal changes, particularly positive ones, are usually expressed with references such as "tight, focused bass," "good midrange detail," "extended and silky highs," etc.---all laudable individual attributes. But the kind of subtle yet significant improvement I'm speaking of breathes new life across the entire range of sonic attributes, enhancing every aspect of the musical experience.

This is what happened to me with the Vibraplane. A certain synergy permeated the individual elements of the usual sonic checklist---and, in a way, superseded them. As a result, I found myself absorbed in one record after another, with barely a thought about sound quality. Clearly, sophisticated pneumatic isolation is a technique that deals with external vibration at a more fundamental level than the usual practices of rigid coupling and elastomer damping, and yet each of these methods plays a critical role in any comprehensive, logical, effective vibe-reduction plan.

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