2) Dunno. To do this right you really need very efficient bass bins. My JBL twin 15" bass bins are rated at 100 dB efficent. So my teeny 1.8 wpc 45 tube pair of mono blocks can get plenty loud for my ears. I think it is more about the efficiency of the speaker and the quality of the tube amplifier, and its power supply for bass. My bass bins on paper state they can get down to 35 Hz. Prolly more like 40 Hz is realistic as I do not always believe what I read. I do believe what I hear with my own ears. I have used many tube amps from a 100 wpc CJ using 8 el34 tubes to my 1.8 wpc 45 amps. A lot of folks are quite happy with solid state to drive their bass bins. I say to all go with what sounds the best to your own ears. There is no absolute right answer in home audio. We all chase the sound of live music and we all fall well short. The closest I have come is my 31" x 31" horns and my bass bins. John