I was persuaded by a salesman at guitar center to get a used pair of JBL EON 15 speakers (both powered) for $320, this a good deal? Do you think I'll be able to cut through my band better with this pair rather than the Logitech Z5500 system? Of course the salesman said I would, but I'd like to hear from you guys...Will I get less distortion/better quality when I crank to compete with a very loud band with this setup rather than the Z5500?