I guess I'm just used to living in 'hiss city' - with the efficiency of my horns, I can hear hiss from my crossover and power amp by themselves out to a foot. To combat noise, I even have my gain structure so that the drive going to the electronic crossover is +15db at a CDs full scale output in order to reduce the noise of the crossover, which uses video buffer amps. The power amp for my high frequency horns (1,200Hz and above) is a single ended triode, which puts out (count 'em) 7 watts - and with my gain structure, it is actually _attenuating_ the voltage being fed to it, to drive the horns.