i just saw this ..hhmm i just woke up..all i can say is keep your volume
low. making small changes on your knob setting might be ok to see what
it does..
i'm sleepy now but.. i dont even remember all your questions now.lol
i never seen a knob that cuts your bass unless it has a minus sign
infront of the number.
id say any knob increases the bass..
good luck...