Hi @Dover , thank you for the detailed description! May I ask what air-suspension table you were using at the time?
My audio room is on the 5th floor of a high rise building (20+ stories) with concrete floor. The TMC optical table that I am using can actually be used in 2 modes. Without air, it act as a sturdy steel table with no compliance; when the air pump is switched on, pistons in the 4 legs raise up by 3/8” and offer air-suspension!
In my system, and to my preference, with air-suspension the sound is more airy, blacker background, soundstage noticeably wider, and separation between instruments also better! Together with the widened soundstage, imaging size of the vocal and instrument also expand slight, which I consider more life like. One time I forgot to switch on the pump, and immediately felt something was off!
I tend to agree with you that the mid bass seems to become a little bit fatter with air-suspension. I consider that simply as more mid bass, but without any loss of definition, so a positive to me. I do understand some audiophiles don’t like air-suspension, thinking it has a “sound” of its own, and I am sure personal preference and the room/system play critical roles in choosing anti-vibration platforms!

