A/V Room Service Equipment Vibration Protectors (EVPs)
My Anti-Vibration Experience
I suppose most audiophiles have tried a number of racks and/or accessory “feet” in an attempt to eke subjectively ever-better performance from their systems. I'm no exception. As with most types of components, my 50 years of experience in this hobby has resulted in owning, using, and comparing a variety of options.
In terms of electronic equipment racks and platforms, I've used everything from a lowly Ikea Lack table, to Sound Organisation and Target racks, Black Diamond Racing Platforms, Bright Star Audio Big Rock sandboxes, inner tube suspensions, and sand filled Little Rock weights, to the Townshend Seismic Sink, to the Arcici Suspense rack, Active Vibraplane (active only in the sense that it has an air pump which automatically occasionally operates to keep the air bladders filled and platform leveled), a Minus K platform, and Mapleshade 4” solid-maple platforms. For accessory feet I’ve used everything from felt pads and tiny vinyl bumpers, to the original Mod Squad Tiptoes and Sorbothane feet, Sims NAVCOM silencers, Vibrapods, Aurios, Symposium Rollerblocks, Mapleshade Isoblocks, Bright Star Audio IsoNodes, Golden Sound DH cones, and Walker Audio resonance control disks.
For speaker stands I've used wooden stools and tables of various heights, as well as purpose-built stands from Sanus, B&W, Sound Anchor, Skylan, Something Solid, and Tontrager, as well as some custom-built fiberglass stands filled with lead shot.
For interfaces between speakers and stands and between stands and floor I've run the gamut from felt, toweling, carpeting, Blu-tac, and Sorbothane, to Navcom Silencers, to roller bearings, short and tall Mod Squad Tiptoes, to rounded metal screw heads, to very sharp spikes of the type which tend to come with speaker stands.
Probably my complexity zenith in this effort involved the isolation system described and shown in my thread, EVS Oppo BDP-105 Mods, Ground Enhancers, Black Discus & Mounting Tweaks.
What I Haven't Tried
I have not tried the latest active suspension devices such as those produced by Herzan and Accurion. Such devices use sensors and actuators to actively counter the effects of detected vibrations at low frequencies in all six degrees of freedom with passive isolation higher up the frequency range. Active isolation is claimed to eliminate the very low frequency resonance of passive isolation systems, resonance which can actually amplify vibrations near the resonant frequency, which is typically below 5 Hz. Active isolation units are thus specified to achieve 90% or more vibration attenuation as low as about 5 Hz.
Problems With Mechanical Isolation Devices
Problems I've encountered with mechanical isolation systems include:
- expense—many would think inordinate expense for an audio system "accessory" with prices for some of the more "serious" passive and active isolation platforms starting at about $2,000 per shelf.
- complex and non-uniform set up; where you put the accessory feet under a component for best sonic results varies from component to component and with equipment racks how you position the equipment on the shelf can seem to make a sonic difference as well
- lack of stability of set up; e.g., the need to keep monitoring the air pressure in air suspension systems for best performance
- seeming lack of universality—what sounds better with one component may not with another, or what sounds better with some types of music sounds less good with others
- lack of a reasonable technical explanation as to why a particular mechanical isolation system should work better than just plunking the component down on any old shelf using its manufacturer-supplied feet; beware of any device for which the manufacturer does not publish measured vibration attenuation results
- vertical height or weight of the isolating system; some of the best—from Minus K, Herzan, and Accurion platforms to Mapleshade platforms and feet—take up a lot of vertical inches in equipment racks making it difficult to mount all the equipment on such devices without adding racks; others, like the Vibraplane, are extraordinarily heavy for each isolating shelf
- weight sensitivity of the isolating devices—the Minus K platforms, for example, while demonstrably sensationally effective at isolating components, only work their best within a narrow weight range mounted atop them; change components and you’ll need to buy a new version tuned to a different load since there is no easy conversion from one weight range to another
- and, most of all, the fact that many such isolation systems, while clearly making a difference in the resulting sound, over time do not make the grade as an overall positive difference producing overall "better" sound.
Different Sound vs. Better Sound
As with the audible effects of cables and power treatments, many audiophiles view mechanical isolation with a sizable degree of cynicism. I think that’s a healthy attitude. There are a lot of companies chasing a shrinking market. Buyers need to be able to separate marketing claims from true performance enhancements.
With audiophile tweaks you should remain skeptical unless you personally can clearly hear a sonic difference and positively classify that difference as not only different, but “better.” Most anything you do to a high-resolution audio system will make a perceptible difference in the resulting sound. But in many cases, differences are just that, mere differences, which one cannot be confident in classifying as "better" sound.
What is "better" sound? For me, from what I believe to be well-made recordings of unamplified instruments in good acoustic spaces, “better” encompasses, among other concepts, a more natural (as in true to what you would have heard live from a good audience seat during the recording session) frequency balance, a more open and organized sound field, more distinct and rounded instrumental and vocal images, “blacker” background, wider perceived range of macro-dynamics and more nuanced micro-dynamics, and subjectively lower distortion of all types, especially high frequencies nasties.
When I speak of "better" sound from here on, that's the meaning of "better" I intend. You may disagree as to what constitutes "better" sound, but I hope this definition clarifies what I mean by "better" in my comments.
[Continued in Part 2 below]