Platter mat insanity

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.

Sleepwalker, Please tell me how a platter mat can affect wow and flutter.  Maybe there would be an effect on measurable rumble, depending upon where and how you measure it, but I am straining to understand your comment on wow and flutter. 

Also, I have owned two SP10 Mk2s and now own an SP10 Mk3.  In all cases, I could not fall in love with the factory-supplied rubber mat(s), thick and heavy though they may be, once I compared them to other options. I am using a Boston Audio Mat2 on my Mk3; this is consonant with the belief that the mat should be acoustically "like" the vinyl LP.  I tried a BA Mat2 on my Victor TT101 and liked it but since then have come to like an SAEC SS300 metal mat, better.  (There's surprisingly very little difference, but I favor the SAEC for better transient response.) On my Kenwood L07D, I have absolutely fallen in love with a custom made copper "platter sheet" that replaces the OEM stainless steel platter sheet.  (Here is where EMI shielding may well play a pivotal role.) These experiences have caused me to throw out the rule book when it comes to mats, except I always have found any sort of rubber mat to be inferior to the other approaches.  That's just me and my experience in my systems.