Zapco - ST-4X SQ III - Class AB, 4-Ch, SQ Power 2Ω: 4 x 95W, 4Ω: 4 x 70W

The Zapco ST-4X SQ III offers signature Zapco sound quality in a compact Class AB design. Tuned for accuracy and musical warmth, it’s built for those seeking high-fidelity multichannel performance in midsize systems or SQ competition setups.

• Channels: 4 (Full-Range, Class AB)
• Power Output:
 • 95 W × 4 @ 2 Ω
 • 70 W × 4 @ 4 Ω
 • 190 W × 2 @ 4 Ω (bridged)
• Total Harmonic Distortion (THD): < 0.5% at rated power
• Signal-to-Noise Ratio: > 90 dB
• Frequency Response: 15 Hz – 30,000 Hz ±1 dB
• Input Sensitivity: 0.25 V – 5 V
• Features:
 • RCA and speaker-level inputs
 • Variable input gain control
 • Variable electronic crossover (HPF/LPF)
 • Variable bass boost
 • Protection circuits: thermal, short, and DC offset protection
• Construction: High-efficiency AB topology with oversized heat sink
• Dimensions (chassis): approximately 160 mm × 58 mm × 300 mm
• Overall Dimensions (with end caps): approximately 160 mm × 58 mm × 325 mm
• Use Case: Ideal for full-range or bridged applications with precision SQ performance