I tried a Ref 110 with my 3.7s. If you do, do not plan on playing anything more than a medium volume. I like orchestral music and even moderately loud sections drove the amp into audible clipping. FWIW, I ended up with 300 wpc monoblock amps (600 into 4 ohms) which sound great. I have struggled trying to make the 3.7s sound as good as I heard at my Thiel dealer but the super-powerful amps are the key in my mind, plus a preamp with superb low end definition.