Hello Vivek,
First, the technical part. For a speaker with a sensitivity of 87 dB, to produce sound energy of 90 dB at a 1 metre distance requires an amplifier power of 2 watts. That's just for average listening. To reproduce peaks in music at the same average level, add another 10 dB. The power required jumps to about 20 watts. No wonder your low powered tube amplifier starts gasping for breath!
Now, change speakers to those of a sensitivity of 96 dB. The power required to sustain the same level of sound drops to about 0.25 watts, with 3 watts for peaks. Your low powered tube amp suddenly develops into a dynamic animal!
Low frequencies, specially, require great reserves in power from the amplifier. This is not reflected in typical specifications. And, small drivers, as in bookshelves, in spite of their ambitious claims, just can't move enough air to reproduce those low frequencies. They jump out of their sockets trying to, and sound terribly strained.
Therefore, to get the high sensitivities throughout the frequency range, you have to use pro-sound drivers. And big ones, of the order of 12" to 15" bass drivers. That makes for big speakers.
Now, for the subjective part. Somehow, tube amps just love high sensitivity speakers, especially horn speakers. It's not only the power game at play here. Tube amps revel at low level detail in music, that's what brings music alive, and horn speakers oblige by reproducing that detail. It's a synergy that happens - you have to hear it to believe it.
Yes, you can build high sensitivity speakers to fit in smaller rooms. Compromises are always there. We do it all the time.
Regards,
Viren
That is such a simple and lucid explanation. Thank you sir.
Cheers,
Raghu
