Search query: pa subwoofer amp with crossover

Product: Rockville RPA5 1000w Peak / 400w RMS (200 x 2) 2 Channel Power Amplifier Pro/DJ Amp Rockville RPA5 400w RMS (200 x 2) 2 Channel Professional/DJ Rack Mount Amplifier. 2U rack space.
Bridged and Stereo output switch makes this perfect for (2) subwoofer, (2) speakers, or (4) speakers.
Built in crossover switch allows make this perfect for speakers, monitors, or subwoofers. Channel A & B Clipping Led Indicators.
Channel A & B Separate Level Controls. Power, signal, overload, clipping, and protection LED indicators on front of amp.
Heavy duty rack mount ears with handles. Built-in dual high velocity quiet cooling fans. Rockville

Product: Nady CX-23SW 3-Way Stereo, Plus Subwoofer Crossover - Fits in a 19" Single Rack Space (1U) – For multi-amplifier setup Splits stereo signals into 3 stereo bands (LOW / MID / HIGH) and a 4th mono band for the subwoofer. For use with 3-way speakers in combination with a subwoofer, the CX-23SW connects directly to the 3 speaker amplifiers and subwoofer via XLR connectors
Phase inversion switches on the MID and HIGH bands allows driver phase adjustment, and low-cut subsonic filters provide low frequency driver protection
Crossover Frequency Controls, and Low/Mid/High/Sub Output Level Controls
Servo-balanced XLR & 1/4" Combo Input Jacks, Stereo Low/Mid/High balanced XLR output jacks and one dedicated subwoofer XLR output jack
Shielded internal power supply with AC voltage select switch (~115V/60Hz or ~230V/50Hz) Nady