High performance bass drive unit from the prestige range. Featuring a composite Aerogel cone and fully ventilated chassis / pole piece, this woofer operates as a pure piston upto 400 Hz with a ruler flat response - the bass output and quality is astonishing; alignments with a f3 of below 30 Hz easily achievable for a realistic in room response to around 20 Hz. This unit is not a subwoofer, it is designed for a stereo pair of the highest quality giving excellent texture, detail and extension. Twin edge wound voice coils can be configured for 4, 8 and 16 ohms. New old stock in original factory boxes - very, very rare, supply is limited.