Nottingham resonance control

Terry9, thank you. Yes, I have doubts about metal cones, they might give me ringing.
Why Baltic Birch and not, say, Brazilian Rosewood or Cocobolo? Or Ebony? In any case, it's an interesting idea.
I am not going to replace arm or cartridge soon - I prefer to jump when I upgrade not to move in small steps. Tweaking and tuning the system is another matter. Ultrasonic record cleaner costs thousands. I might have records cleaned by ultrasonic machine by someone else, but I will not take a risk by mailing my most valuable records, but I can send others. I don't have many records.
I just had an opportunity to upgrade the interconnect from phono, from Maximus to Colossus, but I didn't receive it yet. I think, I will try Walker discs too. I recently got just one 1/2" disc, and the biggest difference for the better it made was by sitting on top of my Nakamichi deck! The deck in turn sits on Boston Audio tuneblocks. So, maybe I should get two more and put them on the maple block - one near tonearm and another near motor. The discs are not expensive and can easily be returned.

You want constrained layer damping to minimize the contribution of your motor to the signal. One layer tries to move against the next, but cannot - it is constrained. The result is heat, not motion. Plywood or slate does this. Brazilian Rosewood does not (although it does look wonderful - a thought - veneer some onto Panzerholz). But prove the concept first.

I doubt very much if metal cones will ring, especially in response to an outside signal. They will, however, limit transmission of vibration. You need to specify shape (cone) not cost. But, they may not work with your system as it is now - I had to insert a cork layer to dampen the sound until I upgraded the tonearm, at which point the cork layers came out and the sound blossomed. Stay empirical, but begin with the physics.

I see. Brazilian Rosewood won't work. Great wood for making guitars, that's why it came to mind.
Not so simple with cones - they remove the vibration at best, then they return some of it. Yeah, shape and material matter. Audiopoints were good cones, no longer made. They work well with my integrated amp.
Probably Vibraplane would be best, but you never really know until you try. Still, you can't try eveything so to a degree you have to guess.
Physics, of course. But at times the laws of physics are so inconvenient.

For everyone's information Nottingham has a new US Distributor. Check out the website audioencountersolutions.com

Boston Audio Mat-1 works great. And also Neuance shelf under the table is a big improvement.

Shakey