SVS makes has two lines of PC (powered cylinder) subwoofers: the PCi and the PC+. The differences between the two are the driver, the amp, and the ports.

The PCi version is less expensive. It uses a 12" ISD (improved standard driver), a 320 watt BASH amp, and has one high-flow port.

The PC+ version is more expensive. It uses a 12" Super High Output driver, a 525 watt BASH amp, and has three tunable high-flow ports.