Shure SCM268 – Four-Channel Transformer Balanced Microphone Mixer

Product Overview

The Shure SCM268 is a four-channel transformer-balanced microphone mixer designed for professional sound reinforcement, broadcast, and commercial AV presentation systems. With four transformer-balanced XLR microphone inputs, five consumer-level aux inputs, a switchable MIC/LINE balanced XLR output, 12 V phantom power, and a 6-segment LED output level meter, it delivers low-noise, high-rejection mic mixing in a compact half-rack chassis suitable for single or dual rack-mount installation. Its transformer-balanced input and output architecture provides exceptional common mode rejection (>80 dB) and quiet performance (-130 dBV EIN) across long commercial cable runs.

Product Description

The SCM268's transformer-balanced inputs on all four microphone channels ensure reliable noise rejection in electrically noisy commercial AV environments such as conference rooms, courtrooms, and broadcast facilities where long cable runs and mixed signal environments are common. The rear-panel recessed MIC/LINE output level switch allows the SCM268 to feed both professional power amplifiers (line level) and devices expecting microphone-level signals without additional pad circuits. Five phono-jack aux inputs (AUX LEVEL INPUTS 1-4 plus a dedicated AUX IN) provide routing flexibility for program audio integration. Built-in 80 Hz low-cut filters on all four mic channels reduce room rumble and handling noise. The half-rack chassis dual-mounts with the Shure SCM262 or a second SCM268 to occupy a single rack space in commercial AV equipment racks.

Key Features

• 4 Transformer-Balanced Microphone Inputs — XLR connectors on all four channels with transformer-balanced circuitry for maximum common mode rejection (>80 dB @ 1 kHz) across long commercial cable runs.
• -130 dBV Equivalent Input Noise — Exceptionally low noise floor supports high-sensitivity condenser microphones and low-output dynamic mics in commercial AV environments requiring clean, quiet audio.
• Switchable MIC/LINE Balanced Output — Transformer-balanced XLR output switches between line and microphone level (rear-panel recessed switch) to match a wide range of downstream commercial AV equipment.
• 5 Consumer-Level Aux Inputs — Four phono-jack auxiliary level inputs (one per channel) plus a dedicated auxiliary input channel accommodate program audio sources and consumer-grade equipment.
• 12 V Phantom Power — Rear-panel recessed switch activates 12 V phantom power on all four XLR inputs simultaneously for condenser microphone compatibility; does not affect dynamic microphones.
• 6-Segment LED Output Level Meter — Front-panel LED meter displays peak output level referenced to balanced line output in dBu; red LED activates at 2 dB below clipping for visual gain staging.
• Built-In 80 Hz Low-Cut Filter — -6 dB/octave high-pass filter on all four mic channels reduces low-frequency noise in commercial AV installations (bypassable via internal modification).
• Half-Rack Single or Dual Mount — Included hardware supports single half-rack or dual rack-mount installation with a second SCM268 or Shure SCM262 in a standard 1RU space.

Typical Applications

• Boardroom and conference room four-microphone mixing for speech reinforcement and AV presentation systems
• Broadcast and recording studio microphone submix with low-noise performance
• House of worship podium, choir, and instrument microphone mixing
• Government space and courtroom four-channel microphone integration with AV systems
• Training room and lecture hall multi-microphone commercial AV deployment

Technical Specifications

Frequently Asked Questions

What is the difference between the SCM268 and SCM262?
The SCM268 is a four-channel mic mixer with transformer-balanced inputs on all channels (-130 dBV EIN, >80 dB CMR), a 6-LED output meter, and five aux inputs. The SCM262 is a two-channel stereo mixer with active-balanced (not transformer) inputs and adds ducking, jukebox mute, and stereo balanced outputs for paging-over-music applications. Choose the SCM268 for maximum noise rejection in multi-mic AV installations; choose the SCM262 for background music integration with automatic ducking.

Can the SCM268 power condenser microphones?
Yes. The recessed 12 V phantom power switch on the rear panel activates phantom power on all four XLR inputs simultaneously. Note: the SCM268 provides 12 V, not the standard 48 V—verify condenser microphone compatibility before deployment. Dynamic microphones are unaffected when phantom power is active.

How does the MIC/LINE output switch work?
The recessed rear-panel MIC/LINE OUT switch changes the signal level of the balanced XLR output. In the LINE position (switch out), it provides line-level output for professional power amplifiers and processors. In the MIC position (switch in), it attenuates the output by approximately 50 dB for connection to devices expecting microphone-level signals.

Can the SCM268 be rack-mounted?
Yes. It is a half-rack unit (8.60 in. wide) and ships with mounting hardware for single half-rack or dual rack-mount installation alongside a second SCM268 or a Shure SCM262 to fill one rack unit.

What warranty is included?
Shure provides a limited 1-year manufacturer warranty on the SCM268. Contact Creation Networks for commercial procurement and AV system integration support.