I've noticed when I really dig in on my bass the notes sounds real compressed at first and never quite come out as loud as when I pluck the string with a regular attack. I don't know if maybe my pickups are too high or I'd it could be a string issue. I notice it most on my A string and the higher strings some, but it kills it when you are really starting to go and it happens. I'm thinking of going to heavier strings to see if that helps. Anyone have an idea what it might be?