The secret to selecting the perfect amplifier chassis, location, topology, and wattage rating can be found inside the loudspeaker—not in the form of a hidden note—but rather in the demands of the speaker itself.
But that’s not the way it all shakes out when it comes to selecting amps and speakers (where we typically follow one of several patterns): matching the speaker to the amp or choosing an amp big enough to work with anything we throw at it.
In the first example, if we have a small amplifier (perhaps a lower power SET), we don’t want to connect to a power hungry loudspeaker. Instead, we’d choose an efficient horn or cone design. Failure to get this right results in clipping and bad sound.
The purchasing pattern most familiar to us is amps big enough to handle just about anything. Several hundred watts will do, even one hundred’s probably stout enough to drive most loudspeakers to respectable volume levels. Is it a perfect match? Who knows.
As I mentioned in the opening paragraph we’d be much better off if all speakers came amplified. Designers could match amps to speakers and customers would be the beneficiaries of perfect matching. If the speaker had nasty impedance dips, or lofty resonances needing taming, no worries. Just match amp technology to speaker requirements and voila! Perhaps the best performance might be a small and sweet tube amplifier driving the tweeter while the bass might benefit from a brute class D beast. Together, sweet music might be the result.
Only, this rarely happens. Why? I am not entirely certain but for the longest time, I suspected two things: speaker designers rarely have expertise in amp designs and people were uncomfortable with the AC cord required for both left and right channels. I am quite certain of the first observation, less of the second since increasing numbers of speakers have plug-in subwoofer amps.
If you want a more personalized answer, watch this video I have recorded for you.