7 sting version of Dimarzio pickups often uses base plate made of fibreglass with layer of cooper. I'm not really good in physics but fibreglass and copper creates some kind if magnetic interference that makes pickup to sound a bit more muddy than 6 stings versions of the same pickup(that uses nickel silver base plate) So by recommendation of my good friend, I decided to upgrade my Crunch Lab 7 and Liquefier7 with Nickel Silver Bass plates. Now pickups have a bit more clarity and top end. I hope it helps some of you. It's very easy upgrade, but some Wax potting might be needed