Why do turntables sound different?


Let's consider higher-end tables that all sound excellent. Same arm/cartridge and the rest of the chain. Turntable is a seemingly simple device but apparently not quite or not at all.
What do members of the 'scientific community' think?
inna
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.
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. 

The corner is the strongest part of a suspended wood floor.  The corner of my room is approx 22 feet away from my speakers. You cannot feel any vibration when standing in front of the turntable stand. You can feel the floor vibrate a bit when standing behind my speakers. I rather have my turntable and all my front end gear (which is tube) as far from my speakers as possible.