CS121
21 inch Subcardioid Subwoofer (Single-amp)
Subcardioid (10 dB rear rejection) nominal beamwidth within operating range

Application Notes:
Pre-Out EQ tab has user-adjustable low pass filter.
LF is wired to speakON pins 1+/-

Technical info:
* Amplifier Gain is set to 32 dB.
* Factory ISVPL Speaker Thresholds and MaxRMS Limiter Thresholds are engaged.