Turntable mat upgrade recommendation for Technics SL 1500 (2025)

That's not good. It means that most of the mat is suspended in air. One Oyaide BR-ONE will get you up 'over' the lip for use with any mat that doesn't fit inside the lip. It's 1mm thick. It's hard, flat, smooth butyl rubber, so doesn't' really have a signature of its own it imparts, which makes it ideal for this purpose. It's not cheap though.

Confirming it overlaps the lip a bit.

I'm not so sure I agree with your assessment. The lip is but .25mm high, and for whatever reason, some part of the engineering of the platter. Why? I have no idea.

Records absolutley have a shape. They are certainly not flat. At least the THT-291 has a relief for the record label. I'd guess that is better to have vs. the lip issue. Regardless, I use a clamp, so that .25mm lip is likely helping my situation.

The Oyaide BR-12 is concave on purpose.

from the Oyaide website: The record disc has a mortar-shaped taper with an elevation angle of 1.0° from the center to the periphery, and by adhering the record disc to the taper, the warping of the record disc is tamed.

Yea, it certainly doesn't leave most of the mat suspended in air

The hanenite is not hard rubber, and the outside edge is chamfered toward the top, so the bottom edge is somewhat flexible too. My mat measure right on 290mm, so I doubt it sticks up any on the edge at all when used on the Technics (but I don't use it on a Technics, so can't be 100% positive). And even if it did, one could just knock down that sharp bottom edge a touch with a piece of sandpaper and a few seconds of manual labor for a perfect fit.

I think the lip is more like 0.50-0.75mm, but using a clamp would certainly help; but I still think most of the under mat for the record playing surface will be suspended in air. Might not be detrimental to the sound though.

Yes, but the bottom of the mat is flat and flush on the whole platter.

For clarity purposes only, I used my digital calipers, measured twice, and got .22mm both times. I exagerrated to .25mm.

Nah, maybe an mm or two will be suspended if that. No way the it’ll be most of the mat. I have that exact mat here, I placed it on the technics, pushing down on the mat a few mm away from the lip exhibits no “play” that would indicate it’s suspended in air. It is a flexible mat.

OK.

Having a mat over the lip does mean the record will be suspended across the platter and supported just around its edge. You can feel this when you press down on the label area.

yes, assuming that the record is 100% dead flat. And as mentioned above some mat makers claim that a concave mat is beneficial.

I had wondered. Don’t the concave mats require the use of a record clamp rather than leaving the record suspended?

TBH I am not 100% sure. I know some mats purposefully create air between the mat and the record, such as the ring mat, reso-mat or the spot mat. I believe the idea behind it is that it will further isolate the record from motor vibrations. Depending on the turntable, this could be beneficial. All the mats I use and used are flat with a label recess so I don’t have any first-hand experience. Using a mat with a concave shape in combination with the weight will mess with azimuth, but not sure if that would be to audible degree. Of course this could be compensated for by adjusting the azimuth for a specific mat - a lot of faffery.

Here's something to try if you have a Oyaide BR-12. I just put it on my Technics upside down and I didn't use a weight. It sits pretty flat and to my ears sounds better than a Technics mat. First impression there was a much bigger sound stage. Worth a go I reckon!

Thanks for explanation. I see the standard mat on the Thorens TD-160 also went this route. With a record on I can feel the label area has no support and the record is just suspended on the ridges.

Some cork mats have cork circles or other shapes in various places that support the record just about the actual mat. I have never tried one, but I am just one of those who wants a mat that fully contacts the record. In fact I use a clamp to make sure of this.