$187.99 $239.99

Refurbished Condition: 100% testing and function is in good condition while outside box worn out and small cosmetic dents. cosmetic damages will vary, including but not limited to, damaged or cracked, bent ears, scratches, dents, etc.

The Sound Town Class-D plate amplifier enables you to build your own powered subwoofer cabinet. The STPA21-710 power amp is equipped with 2 XLR-1/4” combo inputs and 2 XLR (through) outputs. It handles formidable 500W RMS power. Each of the speaker output generates 250W RMS power and allows you to connect two passive PA speakers with the amp. The plate amplifier also comes with master volume control, Low Pass Filter (LPF) adjustment and a polarity switch.

  • 500W RMS plate power amplifier
  • Two speaker outputs with 250W RMS output each channel
  • 2 XLR-1/4” combo inputs, 2 XLR (through) outputs
  • Over current and short circuit protection
  • Sturdy and reliable


Model STPA21-710
Description 2.1-channel plate amplifier (subwoofer + 2 satellite)
Type Class-D
Impedance Supports 4Ω & 8Ω
Power 900W + 2 x 250W RMS @ 4Ω
450W + 2 x 125W RMS @ 8Ω
Feature 2.1-channel, LPF
Input 2 x XLR-1/4" combo (mic/line)
Output 2 x XLR (thru)
Control Subwoofer: volume, LPF, polarity; Satellite: volume, HPF, balance
Protection Overload and overcurrent protection
Technical specifications LPF 40-300 Hz; 200Hz HPF on/off
Voltage 110V-220V switchable
Speaker model# reference CARPO-15SPW, CARPO-15SWPW, CARPO-18SPW, CARPO-18SWPW, METIS-15SPW2.1, METIS-18SPW2.1, CARPO-12DSPW

Dimension & Weight

Product Width (in.) 10.51" Package Width (in.) 11.22"
Product Height (in.) 11.34" Package Height (in.) 12.01"
Product Depth (in.) 2.56" Package Depth (in.) 3.94"
Product Weight (lb.) 5.06 lbs Package Weight (lb.) 6.60 lbs


Manufacturer Warranty 180 Days (6 Months)


SOUND TOWN STPA21-710-R | REFURBISHED: Class-D 500W RMS Plate Amplifier for PA DJ Subwoofer Cabinets, w/ Speaker Outputs, LPF - Wiring Instructions and Connection Diagram to LF (Low Frequency) Woofer