BRAND: McIntosh

SERIES: MX123 A/V Processor
TYPE: Sources

The MX123 A/V Processor marries a long tradition of uncompromising McIntosh sound quality with the latest home theater technologies to bring you an unsurpassed luxury home entertainment experience. It is compatible with all the leading home theater surround sound and object-based 3D audio formats including Dolby® Atmos, DTS:X™ and Auro-3D®. It’s also fully compatible with modern 4K Ultra HD video sources and can upscale lower resolutions to 4K Ultra HD for the best possible picture quality.


  • 10 HDMI ports: HDCP 2.2/2.3, 18Gbps & 4:4:4 Color
  • 4K Ultra HD; Dolby Vision, HDR10 & HLG
  • 13.2 Audio Channels; eARC; Apple AirPlay 2
  • Dolby Atmos, DTS:X, Auro-3D & IMAX Enhanced

The MX123 features upgraded digital audio processing capabilities that results in 2 more discrete audio channels, bringing the MX123 to 13.2 discrete audio channels compared to 11.2 in the previous model. These 13.2 discrete channels are available via both balanced and unbalanced audio outputs that can be used in a variety of home theater speaker configurations; 2 additional unbalanced outputs offer further connection flexibility. DSD and ALAC playback support have been doubled to DSD128 and ALAC 192kHz for better high resolution audio performance.

For the video needs of your home theater, the MX123 has 7 HDMI inputs and 3 HDMI outputs, with each being HDCP 2.2/2.3 compliant. They all also have 18Gbps of bandwidth to support High Dynamic Range (HDR) formats Dolby Vision™, HDR10 and HLG; 4K Ultra HD at 50/60Hz; 4:4:4 color spacing; Rec. 2020; and 3D video pass-through. Enhanced Audio Return Channel (eARC) functionality is included on 1 of the HDMI outputs. eARC offers improved bandwidth so the MX123 can receive higher resolution audio from your TV to produce the best possible sound quality.

Additional connections include: 4 digital audio inputs; 1 balanced and 8 unbalanced analog stereo audio inputs (including 1 dedicated as a Moving Magnet phono input to connect a turntable); an unbalanced 7.1 multi-channel audio input; 3 component and 4 composite video inputs; 1 USB Type A input; 2 unbalanced analog stereo outputs; and 2 composite and 1 component video outputs. It has received Connects with Control4 Certification from Control4®, a leading global provider of smart home automation solutions, with the implementation of their Simple Device Discovery Protocol (SDDP), allowing it to be effortlessly integrated into Control4 automation systems to further enhance the user experience.

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The MX123 can be paired with a variety of home theater amplifiers such as our MC303, MC255, MC257, MC8207, MI347, MI254, or MI128 amplifiers and any of our floor standing, in-wall or in-ceiling speakers to create an enviable and enjoyable cinema experience in the comfort of your home. Front panel buttons or a comprehensive remote control allow for easy system operation. It’s complete with McIntosh design fundamentals of a backlit black glass front panel with an illuminated logo, control knobs, an easy to read display, and aluminum end caps.


Frequency Response:
±0.5dB from 20Hz-20kHz

Total Harmonic Distortion:
0.005% maximum from 20Hz to 20kHz

Rated Output Voltage:
2.5 Vrms Unbalanced
5.0 Vrms Balanced

9 Stereo (8 unbalanced + 1 balanced)
4 Composite
3 Component
2 Optical
2 Coax
1 Multi-channel 7.1 (unbalanced)

15 Balanced (configured for 13.2)
17 Unbalanced (configured for 13.2)
3 HDMI (1 is eARC)
2 Composite (1 for zone B)
2 Stereo (unbalanced for zones B & C)
1 Component

Video Processing:
4K Ultra HD native sources, Upconverting to 4K Ultra HD High Dynamic Range (HDR): Dolby Vision, HDR10, HLG IMAX Enhanced.

Audio Processing:
Dolby: Atmos, TrueHD plus legacy formats
DTS: DTS:X/Virtual:X/HDMaster Audio plus legacy formats
Auro: 3D, Auro-Matic, 9.1, 10.1 IMAX Enhanced

Remote control, network, RS232

Overall Dimensions (W x H x D):
17-1/2” (44.45cm) x 7-5/8” (19.37cm) including feet x 19-1/2” (49.53cm) including the front panel, knobs & cables

55 lbs (25 kg) in shipping carton

Non-McIntosh-Provided Services:
Embedded and/or non-embedded services (including but not limited to AirPlay 2 and Spotify), are necessary for full functionality, are provided by companies unrelated to McIntosh, and are beyond McIntosh’s control. McIntosh cannot and does not warrant against interruption, discontinuance, unsatisfactory performance, reduced Product functionality, or damages of any kind attributable to such services or their providers.