





ZoneMaster® ZM4
Powerful Multi‑Zone Sound in a Compact Rack Unit
The ZM4 fits into a mere 1U chassis but packs four full channels—ideal for powering speakers in multiple rooms without taking up space. Whether you’re running backyard speakers, a secondary stereo, or home theater surrounds, it delivers clean, consistent volume that stays smooth even under heavy loads.
In plain terms: 120 W ×4 into 8 Ω (150 W ×4 into 4/2 Ω; 2‑ohm stable), a Class‑AB input stage feeding premium Class‑D outputs, A/B speaker outputs per channel with stereo/mono per‑zone switching, and bus input with loop‑outs plus per‑zone audio‑sensing and 12 V triggers for painless installs.
What users say
- “Clear, dynamic sound and plenty of headroom.”
- “Handles power‑hungry speakers without flinching.”
- You get real music tone, not just volume.”
Power Output – RMS, Both Channels Driven (20 Hz - 20 kHz)
120 watts x 4 @ 8Ω
150 watts x 4 @ 4Ω or 2Ω
Minimum Speaker Impedance:
A+B Outputs of a Single Channel: 2 Ω
Note: Continuous operation at this minimum impedance might require additional ventilation for the amplifier.
Frequency Response:
20 Hz - 20 kHz, +0/-0.25 dB
5 Hz - 50 kHz, +0/-3 dB
Total Harmonic Distortion:
< 0.05 % at typical listening levels
< 1.0% at full power
Interchannel Crosstalk: 70 dB at 20 kHz
Total Gain: 29 dB (Level controls set to Maximum)
S/N Ratio: >112 dB, input shorted, IHF A-weighted
DC Trigger Requirements: +9 Vdc to +12 Vdc, 5 mA
Audio Trigger Requirements: 2 mV audio signal
AC Power Requirement:
600 Watts maximum
60 Watts typical (music playing in all zones)
30 Watts idle (all zones on)
15 Watts idle (one zone on)
100-250 VAC 50/60 Hz (automatic)
Dimensions:
Width: 17.25" (437 mm)
Depth: 14.25" (362 mm)
Depth: 16" (406 mm) with cables connected
Height, with feet: 2.5" (63.5 mm)
Height, without feet: 1.75" (45 mm), 1U
Weight:
Net: 12 lbs. (5.5kg)
Shipping: 18 lbs. (8.2 kg)
- 120 watts x4 @ 8 Ω
- 150 watts x4 @ 4 Ω or 2 Ω
- 8 speaker connections (A and B outputs for both channels)
- High current for stable operation at 2 Ohms
- Class AB input stage plus premium Class D power stage
- Bus input with looping outputs
- Audio sensing auto-on trigger, independent for each zone
- 12 volt auto-on trigger inputs, one for each zone
- Master 12V trigger input to turn all zones on-off together
- Looping 12 volt trigger outputs
- Speaker level input for expanding systems w/out pre out jacks
- Mono mode combines L and R for single speaker applications
- Separate level controls for all 4 channels
- Detachable speaker connectors accept up to 12 gauge wire
- Short circuit and overheat protection with front panel indicators
- 0.5 watt standby power consumption meets Energy Star & EU specs
- Compact 1u chassis size
- Rack mount kit included in the box
None at this time