I've started a thread here way back when about this combo amp and the external jack. I was curious as to how the amp would displace its wattage. I decided the other day while fulling around with my stuff to just hook my Spectrum cab(2x10&1x18) as the external. It's only a 200 watt amp. Please correct me if I'm wrong. In the case of the 4 ten 50 watts a speaker. If im, let's say, running six speakers from a 200 watt amp that's 34 a piece.....with the spectrum having the 18 im probably looking at around 20 some watts a piece? Please educate me.