really hard to find especially the uk it's a rare Yamaha yst sw800 subwoofer speaker, selling the sub itself as the amplifier for the whole system is broken, while it did work it was very really nice deep bass, rated for under 20hz, if interested in the whole system send me a message and can work something out, but this is for the Yamaha yst sw800 woofer itself. won't find my price point cheaper.
eBay