Usually it is a function of how many crossover stages, not the number of transducers. A three-way speaker should have two crossover networks which in a passive speaker splits the signal between bass and mid frequencies and between mid and high frequencies.
These days many speakers in the professional world are active, in that they have built-in amplifiers that incorporate electronic crossovers and (eg) two or three amplifier stages to match the three frequency bands. This enables the designers to match the amplifier stages and crossover characteristics to the transducers employed for optimum performance across the entire frequency spectrum. Check out ADAM Audio speakers as used by professional recording engineers and musicians in their personal studios.
To fully answer your question the number of transducers does not define whether a speaker is two way or three way (four way is unusual unless a separate sub-woofer is added to a three way system).
Usually it is a function of how many crossover stages, not the number of transducers. A three-way speaker should have two crossover networks which in a passive speaker splits the signal between bass and mid frequencies and between mid and high frequencies.
These days many speakers in the professional world are active, in that they have built-in amplifiers that incorporate electronic crossovers and (eg) two or three amplifier stages to match the three frequency bands. This enables the designers to match the amplifier stages and crossover characteristics to the transducers employed for optimum performance across the entire frequency spectrum. Check out ADAM Audio speakers as used by professional recording engineers and musicians in their personal studios.
To fully answer your question the number of transducers does not define whether a speaker is two way or three way (four way is unusual unless a separate sub-woofer is added to a three way system).