D3806/820000 was one the very first Scan-Speak products, now been on the marked more than 4 decades and continuing beeing successful as one of the best upper midranges on the marked.
Datasheet: Datasheet D3806/820000

Size (inches): 1.5
Fs (Hz): 450
Re (ohms): 5.7
Sensitivity (dB): 89
Qt: 0.48
VAS (ltr.): 0.04
Xmax ± (mm): 0.4

DIY kits for this driver:
SP38/13 made by Troels Gravesen