The SU 650 Subwoofer Unit provides a solution for improving the low frequency response to a public address system, extending the response of the system to below 40 Hz.

The unit features a high powered, long excursion loudspeaker driver unit to maintain linear excursion during program peak and a 2nd order crossover unit to enhance the efficiency of the loudspeaker driver. The driver is housed in a tuned ported 4th order bandpass enclosure constructed from 15 mm medium density fibre board which has been designed to complement the tuned frequency of the system.

A built-in line matching transformer makes the unit suitable for a 70 V and 100 V line distributed speaker system. A low impedance model rated at 8 Ω is also available, modal SU 650L.