I normally run my MarkBass 1x12 combo on stage as a monitor and direct out to the PA in my band. That's 300W to one 12" sub with tweeter. I've been getting more sub gigs lately and have been thinking about getting an extension cab for bands not running subs. Well, I just got booked to sub Friday night and they have no subs. The local GC has a used Genz Benz GB18B cab at a decent price that I can go look at during lunch. It's a single 18 in ported enclosure. 8 ohm speaker, 300W RMS. If i run an extension from my MB, it'll be pushing 500W. I'm a believer in running higher wattage to subs than their rated RMS and leaving the levels on the amp down. I rarely run my MB past 3-4 on the volume and never run over 5. What do you guys think? Can it take it? And of course, i'll play through it first before purchasing.