Should read KEF 3R Reference Rosetta. Speakers were made in England. To start, I know nothing technical about these speakers. They belonged to my late husband. I do have the Installation Manual so here is what I know from it. Five drive units in a four-way configuration are employed in the Model Three. The single Uni-Q driver for upper mid-range and high frequencies, a 160 mm, 6 1/2" drive unit for lower mid-range, plus two internally mounted 200 mm, 8" drive units for low frequencies.
The 25 mm, 1" high frequency unit functions from 20 kHz down to 3kHz, while the 160 mm, 6 1/2" part of the Uni-Q driver handles mid-frequencies from 3 kHz down to 400 Hz. The additional lower mid-range drive unit handles the range from 400 Hz down to 140 Hz where most musical dynamic energy occurs. The two Interported Coupled Cavity bass drivers cover the lower octaves from 140 Hz to 36 Hz, -6 dB.
Speakers are in good condition, There is one small ding on the side of one of the speakers.