I added it to a 151HR six months ago and never ran it by itself until last night. It compliments the 1x15 well, and together they pump out a tight sound with plenty of low end... ...but to my surprise, what I got from it by itself was pretty depressing...even with the bass knob on the instrument cranked up all the way, everything below the low A sounded thin...just hollow & weak overall. I got myself as far into the peripheral of the amp as I could to see if it was the room maybe, but everywhere i stood, it just sounded weak. I've tried various front-ported Markbass 10's cabs in the store that have all sounded great..what's the deal with my Blackline 104? I got it for 300 bucks out-of-box last year. The Blackline 151HR I have sounds just as good as it's Markbass Standard counter-part to me...what gives?