Those Rubber Feet
The feet of a turntable are the only solid pathways to the greater ground that circulating energy seeks; but more times than not, this energy, trying to escape from the turntable, encounters a dead end: rubber feet. In the attempt to "isolate" the turntable from its surroundings, rubber or sorbothane is often employed in the form of "feet," or available as separate "isolators." Sorbothane and rubber solutions are popular and common; it seems to be an inexpensive solution which is intuitively obvious. However, there are specific reasons why Symposium does not and will not employ sorbothane rubber or similar, flexible polymer materials in any of its products. Sorbothane has very uneven characteristics as an energy conductor. While its compliance or softness acts like a "spring" at low frequencies and can be used as an extremely low frequency isolator, it is this characteristic that disables sorbothane from conducting energy to ground - which we have found to be essential for best results. Sorbothane conducts energy at some frequencies, absorbs at others, and stores and releases energy at other frequencies. In other words, a rubber or sorbothane foot acts as a kind of passive equalizer/phase shifter- with a "frequency response" that is far from the ideal, or "flat." Also, because rubber has non-linear storage and release characteristics, it does more damage than merely upset music's timbral color; it interferes with and distorts the vitally important time information by introducing complex, spurious group-delay characteristics back into your system.
