buy stock in Phonak
Get a huge SVS sub and high pass the CV's: that will yield better dynamics and absolute output than you are currently experiencing.
I would also second the pro-audio suggestion-mega watts for way less than consumer gear.
Seriously, that NAD can put out 300 plus clean watts, and pushing the CV's has got to be getting you 120 db output or more, if those old CV's are capable. Are you trying to throw a concert outside or something?