Proficient M4 4 Zone 8 Channel Amplifier

Proficient M4 is a 4-zone, 6-source multi-zone audio amplifier/controller from Proficient Audio Systems, designed for whole-home or multi-room audio distribution.

In excellent condition, it would appear nearly new with minimal to no visible wear: a clean black chassis, pristine front panel with clear labeling and functional buttons/LED indicators, unscratched display or controls if present, and a rear panel with all connectors intact and dust-free. Internally, it would show no signs of heavy use, with original components in good working order, reliable power supply, and full functionality for switching and amplification.

Key Features

- **4 independent stereo zones** with individual control for volume, source selection, and power.

- **6 audio source inputs** for switching between different audio components (e.g., tuners, CD players, streaming devices, etc.).

- Built-in IR control capabilities (source and zone IR outs) for integrating with other AV equipment.

- Keypad support via CAT5 (up to 1000' runs), with options for master keypads, numeric/function keypads, and expandability.

- Party mode and other linking features for multi-zone synchronization.

- Pre-outs for each zone to connect external amplifiers if more power is needed.

- Rack-mountable design suitable for custom installations.

### Specifications (from manufacturer documentation)

**Audio Performance:**

- **Rated Power/Channel**: 30 Watts RMS into 8Ω.

- **Power/Channel (1kHz)**: 45 Watts RMS into 4Ω.

- **THD (at rated power)**: < 0.7%.

- **Frequency Response**: 20Hz–20kHz ±1.5dB (at 1 watt into 8Ω).

- **Signal-to-Noise Ratio**: >95dB (IEC A-weighted, re: rated output, source inputs shorted).

- **Input Sensitivity**: 300 mV (for rated power at max volume control).

- **Input Impedance**: >22 kΩ.

- **Input Overload**: 2.5 V.

- **Bass/Treble Control**: ±10dB @ 100Hz / ±10dB @ 10kHz.

- **Crosstalk Between Sources**: >65dB @ 10kHz.

- **Channel Separation**: >50dB @ 10kHz.

- **Pre-Outs**: Output voltage up to ~1.7V (VC max) or 810mV (NVC), impedance <300Ω.

**Power and General:**

- **Power Consumption**: ~50W idle (no signal); ~110W at 1/8 rated power.

- **AC Power**: 120V AC version (1.8A, fuse T5AL 250V) or 230V version.

- **Dimensions (H x W x D)**: Approximately 5 3/16" x 17 1/8" x 15 1/2" (148mm x 435mm x 394mm).

- **Weight**: ~20 lbs (9.1 kg).

**Control and Connectivity:**

- Supports various keypads and IR integration.

- Contact closures, status outputs, doorbell/page inputs, etc.

- Expandable in multi-unit setups (up to certain zone limits when daisy-chained or linked with compatible models).