Technics SL-1200GAE or VPI HW-40 or …?

Congrats on the choice of TT there are numerous very contented users of DD TT's that come this Production Pedigree.

 As for Mat's it is impossible to recommend a Mat for your set up, and listening environment that will work.

Clean Records are key to maintaining enjoyment, a Sticky Surface Mat will attract dust and other airborne contamination that is not as easy to keep clean as other materials, 

As regards the idea that a mat should be of the same durometer (hardness) as an LP, one ought to keep in mind that that strategy is a two way street. Rumble or any other noise that can emanate from the bearing or motor can be transmitted into the LP by the same route. So, if you adopt the principle that the mat ought to transmit energy into the platter (I don't disagree), you then have to worry about isolating the bearing and any other sources of noise, like even that which can be transmitted by the belt from the outboard motor pulley of a BD, from the platter and mat. Denon paid some attention to this issue in their higher end DD turntables, back in the 80s.

So, if you adopt the principle that the mat ought to transmit energy into the platter (I don't disagree), you then have to worry about isolating the bearing and any other sources of noise, like even that which can be transmitted by the belt from the outboard motor pulley of a BD, from the platter and mat. Denon paid some attention to this issue in their higher end DD turntables, back in the 80s.

Damping between the motor bearing and the platter will allow the tonearm to pick up vibration that might exist in the plinth; the platter surface must be as rigidly coupled to the plinth as possible. To that end the bearing (which is usually low noise anyway) should not be isolated from the platter.

 As for Mat's it is impossible to recommend a Mat for your set up, and listening environment that will work.

This statement is false. The job of the platter pad is to absorb vibration from the LP at all frequencies and to that effect isn't a tone control. If this is being done correctly it will benefit any system.

If you can hear the stylus tracing the groove in a complex passage with the volume all the way down from only a foot away from the cartridge, you know you have a problem with the mat. It should be dead silent even if you are only a few inches from the cartridge as it tracks.

The Denon Split platter design @lewm refers to is very effective…. but i have a spare or two from Peter at and of PbN audio, so i may just glue that Oracle mat to it….

For those who might be interested, Lyra use 4 PbN highly modified Denon split platter decks in their various production / development process…

Finally - kudos to @billstevenson …. except for hard bop… just kidding 

@atmasphere  Ralph - would you mind PM me the part # and adhesive type…. please and thank you !
 

Jim