Item: Scanspeak 21W/8555-00 8" Carbon Fibre / Paper composite Woofer Pair
Price: $260 plus postage. RRP $240 each plus postage. Donation to SNA on sale.
Item Condition: Excellent. Never soldered. Cones and surrounds are perfect. Some stripping away of black paint around mounting holes. Pictures make them look scrappy but they are in really neat condition. Still in original Scanspeak boxes so happy to post.
Reason for selling: NLR.
Payment Method: Pickup - Cash or Paypal. Postage - Paypal (as a friend or add 3%)
Extra Info: A great woofer that is capable of deep bass in sealed or ported enclosures. It has a useful sensitivity of 88dB /w/m - not a super sensitive woofer but the payoff is deep bass in moderately sized boxes.
I would describe the bass as quite dry (subjective opinion), detailed and it has good pitch definition and good damping. The dryness may be result of the distortion signature of the woofer - whereas some paper woofers offer higher levels of 2nd order distortion which can sound "fat" or "warmer".
It has a well designed motor system that allows for very large excursions. Xmech is 12mm+/- and has Scanspeak's SD-1 magnet system that allows for very long excursion where normal woofers might see the voice coil hitting the back-plate.
It has a usefully flat frequency response up to cone breakup. I have heard of people using these in 2 way designs but you'd want to use an active crossover or a steep passive crossover slope and cross it over to a good tweeter quite low.
It has a very cool look with carbon-fibre "veins" running through the unpressed paper cone. It also has an inverted dust cap which will make it suitable for use where there are small children who love to push dust caps in!
Troels did 3 designs with this woofer. http://www.troelsgravesen.dk/ScanSpeak-3WC-C.htm
"The 21W/8555-00 is an all-time classic and with its carbon filler paper pulp cone a potent bass driver, no need to do mkII versions for something that just works. It displays a very nice Qm of 4.5 and a Qt of 0.31, well suited for bass reflex application. A well engineered driver! The current 21W/8555-10 only has an aluminum chassis rather than magnesium - TS data stays the same and from some 40 litres we get an F3 of 35 Hz, quite impressive. This bass driver goes deep from a small volume. Price to pay is little less sensitivity, but it runs very well from my tubed GlowMaster power amp."
As an example you would expect a -6dB point of 25hz in a 50litre ported box tuned to 29hz. Another example would be a 40litre sealed box which would get you a -6dB of 30hz which is very respectable.
Pictures: The white spots in the pictures are dust, not scratches!
I made some DATS tests and took photos of the drivers.. As I would expect from Scanspeak, they measure very close: