The Discovery series offer traditional design, superior sound, a solid construction, and a wide range of variants. Combining these elements – plus a wealth of technical features and finesses – it gives our customers the possibility of acquiring a tailor-made Scan-Speak solution with very good performance at a reasonable low price point!
Datasheet: Datasheet R1904/613001

Size (inches): 0.75
Fs (Hz): 1000
Re (ohms): 2.7
Sensitivity (dB): 87
Qt: 1.61
VAS (ltr.): 0.002
Xmax ± (mm): 0.1

Here you can soon find DIY kits for this driver.