The Symmetric Drive (SD-1) concept with copper in the magnet system was invented by Scan-Speak. High-quality magnet system design has thus been a key feature of Scan-Speak design since the companys inception. The Classic woofers are highly praised, and are used in some of the worlds most exceptional high-end loudspeakers. Some feature Kevlar cones, others have the innovative carbon fibre paper cones.
Datasheet: Datasheet 21W/8555-10

Size (inches): 8
Fs (Hz): 20
Re (ohms): 5.5
Sensitivity (dB): 87
Qt: 0.31
VAS (ltr.): 134
Xmax ± (mm): 6.5