Amazon.com: Yamaha Audio 10" 100W Powered Subwoofer - Black (NS-SW100BL)
Yamaha HiFi NSSW050 B 8" Active Subwoofer w/ Twisted Flare Port & Advanced YST II - Black - Canada's Favourite Music Store - Acclaim Sound and Lighting
Yamaha's MSP3A is a powered monitor with a unique twisted bass port
Yamaha's NS-SW300
New *Dimple" Precision Ports... - Techtalk Speaker Building, Audio, Video Discussion Forum
Yamaha Subwoofer Speaker with 130W Output Power Twisted Flare Port (Black) | eBay