the key specification is a thing called acceleration factor.
the smaller driver has a larger acceleration factor.
two smaller drivers with the same swept area as a single larger driver..the two smaller ones (~7") will create a notably more articulate bass and have better integration with say, a electrostatic panel- vs that of lets say..a single 10".
eg:
www.audiotechnology.dk
C-Quenze 15 H 52 06 13 SD (5")
Acceleration factor: 674
C-Quenze 18 H 52 17 06 SD (7")
the smaller driver has a larger acceleration factor.
two smaller drivers with the same swept area as a single larger driver..the two smaller ones (~7") will create a notably more articulate bass and have better integration with say, a electrostatic panel- vs that of lets say..a single 10".
eg:
www.audiotechnology.dk
C-Quenze 15 H 52 06 13 SD (5")
Acceleration factor: 674
C-Quenze 18 H 52 17 06 SD (7")
Acceleration factor: 499
C-Quenze 23 I 52 20 06 SD (9")
Acceleration factor: 423
So you get more cheap thump with the larger single driver, but you don’t get articulation. Articulation requires a high acceleration factor. Which is generally with smaller drivers, due to lower mass smaller cones.
IIRC, a tweeter runs near 1000, or just above it, maybe. Thus the 674 of the audio technology driver is crazy fast. This is a difficult spec to find as many driver manufacturers might be embarrassed to print it.