Biamping with tubes and SS: Input sensitivity key?

When biamping a low sensitivity speaker (85db), 4 0hm impedance, with a 800 Hz crossover with a TAD-60 (input sensitivity given as 1 volt or more) and, eg, a Belles 150A reference, with an input sensitivity of 1.4 Volts, and a volume control on the TAD, will it be necessary to get an attenuator on the inputs of the SS amp to equate the 2, since adjusting the output of the TAD will still make it less than the higher powered amp? Is 60 WPC tube power enough to drive the major energies above 800 Hz, which is where mid-range and highs predominate? Is this correct or is there another way of attenuating the input of the higher powered amp? (Not interested in playing with additional or active crossovers. Only in "simple" remedies". Or does someone know of a comparable quality amp with an input sensitivity of 1 volt? I have the TAD-60 and am looking for a suitable SS amp with at least 150WPC with sound similar to the Belles. Unless you all tell me that the TAD-60 is not powerful enough to provide power above 800 Hz to such an insufficient system,then I will look further.