In the Square days... the suggestion was 4b for highs 7b for lows. sitting with both cubed seems the new 7s do top and bottom really well. Note the 4b3 has less hours do they really need cook in time ? 7b3 couple hundred hours.
Did the 7b3 really change that much to out shine the 4b3. whats a better amp to use with the Model T. will be adding 10b sub crossover and dual model t subs
Thanks