That means the 12 mats I have are interacting with each other and multiplying their effect on equipment both horizontally and vertically. I guess the mats are benefiting equipment on the adjacent rack (equipment 1' to 3' away from mats including 2 turntables, and a cassette deck) as well as vertically between rack levels (my VPI SRS speed controller and my Alesis Masterlink). The latter two are sandwiched between the phono/preamp, the EAR Acute CD player and below the Bryston BIT-20.
I still haven’t moved the mats to the recommended positions with the labels facing the equipment and the doubling mats magnetized sides together. They’re working together so well as stacked and with the magnetized sides facing the equipment.