@slaw,
Remember the mat I am using is 3-layers. The center layer (the thickest part) is not solid - its porous, and overall the mat stiffness is 85 durometer so the mat acts to damp/isolate the record from the platter. I use the reflex clamp to make sure the record is in full contact with the mat to get the damping from the stylus as it beats the dickens out of that record with applied pressures >10,000 psi and accelerations >1000-g's.
Also, I modified my TNT to add a cast AL 1/4" thick constraining layer with viscoelastic layer that is bolted to the plinth with a clamping force of 2000 lbf at four points (5/16"-18 torqued to 10 ft-lbs) symmetrical about the platter (same one you have). The plate was machined and installed in a manner (on bottom) that it is not in the load-bearing path. I also use the plate as a ground-plane, the platter bearing is grounded to the plate that measures in sq-ft (covers the entire bottom except the platter bearing nut and the corner posts) and the plate is then grounded to earth. Before the mod if I tapped the plinth I got a response from the speakers - after -nada.
Is this the wrong approach? I beg to differ; and am I going to try your mat - no. What I have is working - just as what you have is working. There is no "The" way - only a multitude of "A" ways; and as the old saying goes - if its not broke - not reason to fix.
Remember the mat I am using is 3-layers. The center layer (the thickest part) is not solid - its porous, and overall the mat stiffness is 85 durometer so the mat acts to damp/isolate the record from the platter. I use the reflex clamp to make sure the record is in full contact with the mat to get the damping from the stylus as it beats the dickens out of that record with applied pressures >10,000 psi and accelerations >1000-g's.
Also, I modified my TNT to add a cast AL 1/4" thick constraining layer with viscoelastic layer that is bolted to the plinth with a clamping force of 2000 lbf at four points (5/16"-18 torqued to 10 ft-lbs) symmetrical about the platter (same one you have). The plate was machined and installed in a manner (on bottom) that it is not in the load-bearing path. I also use the plate as a ground-plane, the platter bearing is grounded to the plate that measures in sq-ft (covers the entire bottom except the platter bearing nut and the corner posts) and the plate is then grounded to earth. Before the mod if I tapped the plinth I got a response from the speakers - after -nada.
Is this the wrong approach? I beg to differ; and am I going to try your mat - no. What I have is working - just as what you have is working. There is no "The" way - only a multitude of "A" ways; and as the old saying goes - if its not broke - not reason to fix.