Audio Choice Qm4 Manual Link - |work|
Since "QM4" most commonly refers to the QSC Q-SYS Core Manager (or QIO Series) or potentially a specific Quad Motor controller in engineering contexts, and "Audio Choice" may refer to a specific brand or a general purchasing decision, I have created a technical support article below.
The Audio Choice QM4 (by SoundTech) is a vintage 4-channel 100W powered PA mixer frequently used for karaoke, small live performances, and mobile sound setups. Manual and Documentation audio choice qm4 manual link
Power Output: 100 Watts total power (typically rated at 4 ohms). Since "QM4" most commonly refers to the QSC
: Includes master level controls, a spring reverb adjustment, and an effects (EFX) loop. : Line out and a footswitch option. Where to Find Manual Information Since Audio Choice was a brand under Bridging Configuration: The QM4 allows bridging of channels
- Bridging Configuration: The QM4 allows bridging of channels 3&4 (and 1&2), but the polarity for the speaker wires is non-standard compared to competitors.
- Input Sensitivity (Gain) Range: The manual provides the specific voltage range (typically 0.2V to 6V) to match your head unit’s pre-out voltage. Overlooking this causes clipping.
- Crossover Multipliers: The QM4 has a bass boost circuit and a variable LP/HP filter. The manual includes a frequency multiplier chart that is not printed on the amplifier chassis.
- LED Diagnostic Codes: The power/protect LED blinks in specific patterns. Only the manual translates these patterns (e.g., 2 blinks = short circuit, 3 blinks = thermal overload).
Hope this saves someone an hour of frustration. Drop a comment if the link is dead and I’ll try to re-find it. 🔧
Individual Controls: Each channel features independent gain, tone (high/low), and reverb controls. Master Section: