Audio Choice QM4 (often listed as the AudioChoice by SoundTech QM4
) is a vintage 100-watt, 4-channel powered PA mixer head. While an official PDF manual "link" is not currently hosted on a primary manufacturer site, you can find operational details and secondary resources through the following channels: Core Specifications & Features
If you are looking for the manual to understand the unit's capabilities, the QM4 typically includes: Power Output : 100 Watts RMS at 4 ohms. : 4 input channels with combination 1/4" and XLR inputs.
: Individual gain, 3-band EQ, and reverb controls for each channel. Master Section
: 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
, tracking down documentation often requires looking for legacy SoundTech support: Vintage Gear Communities : User-contributed manuals are frequently uploaded to
listings where sellers sometimes include photos of the original printed manual. Soundcraft Legacy Support
: SoundTech was historically associated with the same parent groups as Soundcraft. You can check the Soundcraft Manuals Archive
for broadly similar 4-channel powered mixer layouts, though a direct QM4 link may not be listed. Caution on "QM4" Searches
: Be aware that a search for "QM4 manual" often returns results for the TDK-Lambda QM4 Power Supply Q Acoustics M4 Soundbar , which are entirely different products. Basic Operating Instructions
If you cannot find the physical manual, this unit follows standard analog PA logic: Input Connection
: Connect microphones via XLR or instruments via 1/4" cables to channels 1–4. Gain Staging audio choice qm4 manual link
: Turn up the channel gain until the signal is clear but not distorting. EQ Adjustment
: Use the High, Mid, and Low knobs to shape the sound (turning clockwise boosts frequencies). Master Volume
: Ensure the Master volume is low before powering on, then gradually increase to the desired room level. specific technical issue like wiring the speakers or troubleshooting the reverb? QM4 AND QS4 Instruction Manual - TDK Product Center
Audio Choice is a brand often associated with Studio Technologies, and the QM4 is a robust, professional-grade mixer used primarily in broadcast and commercial audio installations.
Here is the most direct path to the manual, followed by a summary of its key features and operations in case you need immediate assistance.
Manual Solution: Check the Mode Switch located between the RCA jacks. If it is set to "4CH" but you are only using a single set of RCAs from your head unit, the front channels will be silent. Move the switch to "2CH" to duplicate the signal to all four channels.
If the device is not passing signal:
For the most accurate and up-to-date manual, users should navigate to the official QSC Professional Audio Resource Center. Search for "QIO Series" or "QM4" to find the latest PDF.
Note on "Audio Choice": If you are referring to a specific decision between audio codecs or a different brand entirely (e.g., a hearing aid loop system or a specific motor controller for audio reels), please specify the manufacturer. The guide above assumes the industry-standard QSC QM4.
The Audio Choice QM4 (often branded as Audio Choice by SoundTech) is a portable 4-channel powered PA mixer designed for small venues, musicians, and DJs. While an official PDF manual download is currently unavailable, you can find the primary features and specifications below from the Audio Choice QM4 Reverb listing and Product Details. Key Features & Specifications Power Output: 100 Watts RMS @ 4 ohms. Channels: 4 dual-input channels.
Inputs: Combination XLR and 1/4" jack ports for each channel. Audio Choice QM4 (often listed as the AudioChoice
Individual Controls: Each channel features independent gain, tone (high/low), and reverb controls. Master Section:
Main Controls: Master level and 3-band Master EQ (Treble, Mid, Bass).
Built-in Reverb: Global spring reverb adjustment for the entire mix.
EFX Loop: Dedicated effects loop for connecting external signal processors.
Line Out: Standard line output for recording or connecting to larger PA systems. Footswitch Jack: Option to toggle effects remotely.
Physical Build: Rugged, rectangular chassis with built-in handles for portability. Mixer Dimensions: Approximately 18.5" W x 11.5" D x 6" H.
Weight: Approximately 9.5 to 20.5 lbs (depending on if weighed as a standalone head or with included speakers). Typical Setup Included
The QM4 was frequently sold as a complete system (sometimes referred to as the C100 system) which included: Two 10" 2-way speaker enclosures. Speaker cables and a microphone.
The Audio Choice QM4 (often listed as Audio Choice by SoundTech QM4) is a vintage portable PA system widely used for karaoke, small venues, and rehearsal spaces. It typically consists of a 4-channel powered mixer head and two matching speaker enclosures. Audio Choice QM4 Manual and Documentation
Finding an original PDF for this legacy system can be difficult as it is a discontinued model. However, digital copies and related support materials can be found through various online databases:
ManualsLib Archive: Provides digital versions for similar era equipment and often lists the Q M4 Soundbar manual (note: ensure you are searching for the "Audio Choice" PA system and not the Q Acoustics M4 soundbar). Note on "Audio Choice": If you are referring
Reverb Listings: Frequently contain photos of the original back panels and control layouts, which serve as a visual reference for setup.
Secondary Support Sites: For specific power supply or technical internal specs, the TDK Product Center hosts instruction manuals for QM4 power modules often found in professional audio gear. Key Specifications and Features
The QM4 system is valued for its "rugged and easy to operate" design. Specification Power Output 100 Watts RMS @ 4 Ohms Mixer Channels 4 Channels with independent Gain, Tone, and Reverb Inputs Combination 1/4" and XLR ports per channel Master Controls 3-Band EQ, Master Reverb, and Level controls Outputs EFX Loop, Line Out, and Footswitch option Speakers Two 10" enclosures with performance-rated horn tweeters Weight Mixer head: ~9.5 to 20.5 lbs; Speakers: ~22 lbs each Setup and Operation Guide
Placement: Place the mixer head on a flat surface and position the 10" speakers at least 6–10 feet apart for optimal sound dispersion.
Connections: Use standard 1/4" speaker cables to connect the "Speaker Out" ports on the rear of the mixer head to the inputs on the speaker enclosures.
Input Setup: Connect microphones via XLR or instruments via 1/4" jacks to any of the four channels.
Audio Tuning: Start with the Master Level low. Adjust individual channel Gain and Tone to desired levels before gradually increasing the Master Volume and 3-Band EQ.
Reverb: Use the individual channel reverb knobs to add depth to vocals, controlled further by the master reverb setting. Common Uses
Karaoke: High portability and multiple mic inputs make it a favorite for home or bar setups.
Rehearsals: Ideal for band practice where a simple, reliable 100W vocal monitor is needed.
Public Speaking: Clear enough for bar trivia or small conference presentations.
For those looking to purchase or replace parts, units often appear on marketplaces like Reverb and eBay. QM4 AND QS4 Instruction Manual - TDK Product Center