Platter mat insanity

I will preface this post with the disclaimer that I am NOT an engineer and do not have a vast knowledge of the dynamics of a stylus in a groove going around in circles. However, I can't help thinking that this is somehow analogous to salmon fishing in British Columbia. If one is motoring along on a choppy ocean (substitute the grooves in the record) and just sits on a bench, your butt is constantly losing contact with that bench due to the bounce created by the waves. However, if you stand up in the boat and use your legs as mild shock absorbers, everything calms down and you can enjoy the ride. Is it possible the lack of support under the record somehow allows the stylus to stay in contact with the groove by microscopically reducing the "bounce"?

These last few posts sort of illustrate the "dilemma", if this issue could take on the dimensions of a real dilemma.  I cannot disagree in the slightest with what Tom Mackris wrote.  It makes perfect sense.  But then we have to take into account the actual experiences of the rest of us.  Mats with an acoustical impedance close to that of vinyl are preferred by many but not all.  And why do metal mats occasionally sound really good?  Many of us pay many hundreds of dollars for copper mats, because we think they sound great and that copper sounds better than other metals, for example. (In this case, I think part of the mechanism has to do with the copper mat acting as an EMI shield, and maybe copper, being softer than many metals, is closer in its acoustic impedance to vinyl than other metals.) Likewise, I am not going to tell a person who loves the ringmat or the resomat that they are "wrong".  I would agree that some of these choices are preferred because they may generate a kind of euphonic distortion, but that's OK.  Platter mats are like seasoning on food; a small detail that makes a big difference.  Anyway, for noromance, I am convinced that he is liking the undamped sound that arises from raising the LP off the platter.  I think he proved that to himself with his experiments.

Can't agree that any of this pertains to the thick rubber mats that were typically supplied with even the best Japanese turntables of the 70s and 80s.  Almost any alternative will sound better, IMO.

@noromance the 1/4” thick mat that Technics supplied on the SL-1700mk2 and 1800mk2, 1600mk2 and SP-10mk2 and SP-10mk3 is very dense and much more rigid as a result. Its dense rubber compound makes it an excellent vibration isolator, making the above series of turntables second to none for rumble in addition to being second to none for wow and flutter. Yes, they could have better tonearm geometry, but you can’t deny that Technics knows more about turntable design than nearly any other turntable manufacturer  still in that business. 

@noromance ,

Yes there should be room for the lp label, but what I was referring to is that at least 50% of all lps have a raised center right around the spindle hole at around 1 & 1/4" in diameter.

I’m not sure if your original post diagnoses the difference you heard properly. There may be more going on?  Your 10" lp as a platter mat seems like a good idea on paper and it may have provided good results on some lps but I'm skeptical of it going forward.

Steve, I have done some more tests using different recordings (including my aforementioned spouse in the listening session). The results as you suspect do vary depending on the recordings. Older live recordings sound excellent. Newer mixed recordings sound "messy" and "more 3D" and "echoy" according to my spouse. She preferred most well-recorded live jazz with the vinyl off the platter and other recordings on a soft rubber mat (with consequently softer presentations) Now, one could argue that what she was hearing was more insight into poor recordings. I don’t know. We compared many of the tracks to Tidal.com hifi equivalents which was another story.