ok heres the deal with the Peavey TNT 115 older version of the combo it has a Crossover network. Both High and Low output jacks. It has pre amp out and pwr in jacks. but it has 1 thing im not to sure i needed for an ext cab, a spkr out jack. What i want to do is give myself more airmovement. not volume as such because i know by addnig more it reduces watts. but as i said i want more airmovment giving me more dynamic volume. i was wondering if i could connect an ext cab to the high or low output jacks no the crossover network, or frmo the preamo out. and if so what kind of cab do you suggest. at the moment the combo plays into a 1x15 scorpian spkr. so should i get a 2x10 or another 1x15 cab, or am i waisting my time. hope use can help. PS is there any other way i can get more air movment?