Just bought these and the matching powered EV ZLX12P tops. Run QSC touchmix 16 board. Love the tops and the board. Issue: one sub seems blown and farts out like wood deck vibrating. Other has limiter light always on. I run the level full up on the powered sub and then mix gain structure and volume from board. Nothing clipping and tips are set to crossover unit to the spec stated good for. Are these subs bad? Meaning should I get something more powerful? Why the limiter on always? Don't feel I should not be able to run these wide open. 4 piece cover band and not my first rodeo mixing sound.