Why do turntables sound different?

 I agree it is all about vibration and speed stability. I am puzzled when I see a high priced turntable sitting on a rack between two speakers. The positioning of the turntable to avoid vibration is critical.

 I have my turntable in the corner on the opposite side of the room from my speakers. It sits on a 3" maple block which sits on a  VPI turntable stand filled with sand. I have all my front end equipment in that corner as far from the speakers as possible. I run a pair of 9 meter interconnects from the preamp to the amp which sits between the speakers.

nknor instead of getting the TT out of the room and spending huge $$$ on ic's and speaker cables why not get some great isolation platforms like minus-k or Vibraplane? Problem solved.

 rsf507, What about airborne vibration?

Since the resonant frequencies of the turntable platter, tonearm and cartridge are intentionally designed to be much lower than the lowest airborne vibration frequency you can pretty much ignore airborne vibration. 

@lostbears I have my turntable in the corner on the opposite side of the room from my speakers. It sits on a 3" maple block which sits on a VPI turntable stand filled with sand. I have all my front end equipment in that corner as far from the speakers as possible. I run a pair of 9 meter interconnects from the preamp to the amp which sits between the speakers

Placing a TT in a corner is worst than between the speakers due to the fact that corners collect and reflect acoustic energy which would be transferred to the table.