The AudioChoice QM4 manual is functional for basic setup but falls short for advanced users. If you’re a beginner plugging into a phone or laptop, you’ll be fine. If you need to understand gain levels, filters, or update firmware, you’ll end up searching online forums.
Recommendation for the manufacturer:
For users: Download the manual from the official website (if accessible) and join the AudioChoice Facebook group or Discord – the community has filled in many gaps the manual leaves open.
The Audio Choice QM4 (by SoundTech) is a 4-channel, 100-watt powered PA mixer head designed for live sound reinforcement, such as small club gigs, band practices, or karaoke.
While a dedicated digital manual is rare for this discontinued unit, the following operational and technical information serves as a comprehensive guide for its use. Core Specifications Power Output: 100 Watts RMS at 4 ohms. Channels: 4 independent input channels.
Inputs: Each channel features combination XLR (balanced) and 1/4" jack (unbalanced) inputs.
Weight: Approximately 9.5 to 20.5 lbs depending on the specific model variation/enclosure. Operational Controls Per-Channel Controls: Gain: Sets the input sensitivity for the specific channel. Tone: Basic equalization for individual sound sources.
Reverb: Controls the amount of built-in spring reverb effect applied to that channel. Master Section:
3-Band EQ: Global Low, Mid, and High frequency adjustments for the overall output.
Master Level: Controls the final volume sent to the speakers.
EFX Loop: Allows for the connection of external effects processors.
Line Out: For sending the mixed signal to another amplifier or recording device. audio choice qm4 manual
Footswitch Jack: Typically used to remotely toggle the internal reverb. Setup and Safety Instructions
Speaker Connection: Use standard 1/4" speaker cables to connect to passive enclosures. The system was originally bundled with 2x10" enclosures.
Power Sequencing: To protect your speakers, always turn the Master Level to minimum before powering on. Turn the power amplifier (PA head) on last and off first in your signal chain.
Clipping: If the "CLIP" or "PEAK" indicator lights up, reduce the individual channel gain or master volume immediately to prevent distortion and hardware damage.
Maintenance: The unit contains no user-serviceable parts. If the master EQ becomes "scratchy" over time, it may require professional cleaning of the internal potentiometers. QM4 AND QS4 Instruction Manual - TDK Product Center
Audio Choice QM4 (often branded as Audio Choice by SoundTech
) is a 4-channel powered PA mixer designed for portability and ease of use in small venues, practice spaces, and karaoke setups. While a dedicated digital "manual" is rare for this vintage unit, its functions follow standard analog mixer logic. Core Specifications & Features
The QM4 is a "powered head," meaning it combines a mixer and a power amplifier in one unit. Power Output
: 100 Watts RMS at 4 ohms (typically 2 x 100W for stereo models). Input Channels : 4 mono channels, each equipped with: Combination Inputs
: Accepts both XLR (low-impedance) and 1/4" (high-impedance) cables. Per-Channel Controls : Individual knobs for (often a single high/low sweep), and Master Section Master Level : Controls the overall volume of the system. : Global adjustments for Low, Mid, and High frequencies. Reverb Master
: Global control for the built-in spring or digital reverb effect. The AudioChoice QM4 manual is functional for basic
: 1/4" Send and Return jacks for connecting external processors.
: To send the signal to another amplifier or recording device. Footswitch Jack : Allows hands-free toggling of the internal reverb. Operational Guide
: Connect your speakers to the 1/4" outputs on the rear panel before turning the unit on. Using a 4-ohm or 8-ohm load is standard; ensure your speaker cables are unshielded "speaker" cables, not "instrument" cables. Input Gain
: Plug in your microphone or instrument. Start with the channel Master Level
low, then gradually increase them until you reach the desired volume without the "Clip" light (if present) flickering constantly. Tone Shaping
: Use the per-channel Tone knobs to remove "mud" (turn left) or add "crispness" (turn right). Use the Master 3-Band EQ to compensate for the room's acoustics.
: Turn up the channel Reverb knob to decide how much of that specific voice/instrument goes to the effect, then use the Master Reverb knob to set the overall "wetness" of the sound. Typical Applications Small Gigs/Coffee Shops : Ideal for acoustic duos or solo performers.
: The built-in reverb and multiple mic inputs make it a popular budget choice for home or bar setups. Public Speaking : Portable enough for seminars and church halls. Where to Find More Info
Audio Choice QM4 (often branded as Audio Choice by SoundTech
) is a 100-watt, 4-channel powered PA mixer head typically sold as part of the C100 portable system. While a formal digital manual is rare, the device's straightforward analog design allows for easy operation based on its physical controls. Musician's Friend Core Specifications Power Output : 100 Watts RMS at 4 Ohms. : 4 independent input channels. Dimensions : approximately 18.5" W x 11.5" D x 6" H.
: Mixer head weighs roughly 9.5 to 20.5 lbs depending on the specific revision/listing. Key Controls & Features Input Options : Each of the four channels features combination (line) inputs. Channel Controls : Individual knobs for on every channel. Master Section : Includes a (High, Mid, Low), a master control, and a master Connectivity : For connecting external effects processors. For users: Download the manual from the official
: For sending a signal to another amplifier or recording device. Footswitch Jack : Allows for remote toggling of the built-in spring reverb. Basic Operation Guide Connections
: Plug microphones into the XLR ports and instruments (like keyboards or guitars) into the 1/4" ports. Connect your passive speakers to the outputs on the rear using 1/4" speaker cables.
: Ensure master volume is at zero before turning on the power switch to avoid pops. Setting Levels
: Adjust individual channel gain until the signal is clear without distortion, then use the master level to control overall volume. Tone Shaping
: Use the individual channel tone knobs for quick adjustments and the master 3-band EQ for room-wide sound correction.
The Audio Choice by Sound Tech QM4 is a 100-watt, 4-channel powered mixer head designed for small PA systems, featuring XLR/1/4" inputs, individual channel EQ, and onboard reverb. Operated by connecting passive speakers to the rear output and balancing channel levels with the master volume, this legacy unit is frequently found on reselling platforms. For a detailed listing with specs, visit Reverb.
Since "Audio Choice" is not a widely recognized major brand for professional audio equipment, it is highly likely you are referring to a Theatre Solutions QM4, QTX QM4, or a generic 4-Channel Stereo Amplifier often sold under various brand names (like Adastra or Velleman).
These units are commonly used for multi-room audio or small commercial installations (restaurants, shops).
Below is a comprehensive guide based on the standard operations of the QM4 Series 4-Channel Amplifier.
| Status | LED Behavior | |--------|---------------| | Charging | Red solid | | Fully charged | LED off / Blue solid (if on) | | Bluetooth pairing mode | Blue flashing quickly | | Bluetooth connected | Blue solid (or slow pulse) | | Low battery | Red flashing every few seconds | | AUX / microSD / USB mode | Blue solid or slow blink (varies) | | FM radio | Blue slow blink |
The QM4 includes three preset equalizer modes:
Thank you for purchasing the Audio Choice QM4. This manual provides instructions for safe operation, setup, and maintenance of your device. Please read it carefully before use and keep it for future reference.
| Problem | Possible solution | |---------|------------------| | Cannot power on | Charge battery for at least 30 minutes; try a different USB cable. | | No sound / distorted audio | Check volume level; ensure Bluetooth device is not muted; move device closer. | | Bluetooth not pairing | Turn QM4 off/on; delete old “QM4” from phone’s Bluetooth list; re-pair. | | microSD/USB not recognized | Format card as FAT32; limit file depth (no subfolders over 2 levels). | | FM radio poor reception | Extend any attached USB/AUX cable as an antenna; move near a window. |