Marantz Model M4

Soundproofing an entire house without multiplying devices or sacrificing audio quality is a technical challenge that few manufacturers tackle with elegance. With the Model M4, Marantz brings its sonic signature to the world of residential installation by offering an amplifier capable of powering four distinct zones from a single rack-mount chassis. A solution designed for integrators and custom-installation enthusiasts.

Four zones, eight channels, one single device

The Model M4 is built on an eight-channel architecture divided into four independent stereo zones. Each zone has its own volume, balance, and EQ settings, allowing you to tailor the sound to the acoustic characteristics of each room. Volume limits can be adjusted between 80 and 100% per zone, a useful feature for protecting certain speakers or harmonizing levels throughout the home.

Output power reaches 100 watts per channel into 8 ohms and 125 watts into 4 ohms. These figures comfortably drive in-wall speakers, floorstanding models, or outdoor systems. For configurations that require more power on fewer channels, bridge mode is available.

Each zone also benefits from high-pass (40 to 250 Hz) and low-pass (40 to 120 Hz) filters, along with a dedicated subwoofer output. This flexibility enables hybrid setups combining satellite speakers and subwoofers in certain rooms, while retaining a traditional stereo configuration elsewhere.

Marantz sound signature in an integrated format

Signal processing is based on Marantz’s proprietary Marantz Musical Digital Filtering (MMDF), designed to preserve natural timbre and transient fluidity. The M4 decodes Dolby Digital and Dolby Digital+ streams, as well as stereo and multichannel PCM formats. Playback of 2.8 and 5.6 MHz DSD files is also supported, a real plus for high-resolution music libraries.

Audio files stored on a NAS or USB drive can be played up to 24-bit / 192 kHz for WAV, FLAC, and ALAC formats. Compatibility with common compressed formats (MP3 up to 320 kbps, AAC, WMA) ensures broad support for all kinds of sources without prior conversion.

A “dialogue enhancement” mode improves voice intelligibility when watching TV content, while the “TV sound grouping” mode allows you to synchronize multiple zones for consistent playback of the same program.

Built-in streaming and multiple sources

The Model M4 features the HEOS platform, which handles both streaming services playback and multiroom management. Spotify, Tidal (including HiFi), Deezer, Amazon Music, TuneIn, and SoundCloud are directly accessible, depending on regional availability. AirPlay 2 and Spotify Connect round out the offer for seamless integration with Apple devices and the Spotify ecosystem.

On the physical connectivity side, four stereo RCA inputs and two optical TOSLINK inputs accommodate traditional analog and digital sources. The two Ethernet ports provide a stable network connection, preferable to Wi-Fi in permanent installations. Four USB-A ports allow direct playback from FAT32- or NTFS-formatted storage devices.

Worth noting: Bluetooth is not built in. This common choice on installation-focused equipment favors wired network stability and avoids potential interference in environments with many wireless devices.

Home automation integration and professional installation

The Model M4 is designed to integrate with residential control systems. Compatibility with Crestron, Control4, and AMX enables integrators to incorporate the amplifier into automation scenarios that also include lighting, motorization, and security. The HEOS app (iOS and Android) offers an alternative for everyday control without any specific programming.

The four 12 V trigger outputs (one per zone) can automatically turn on associated equipment, such as additional power amplifiers or motorized screens. Four stereo RCA pre-outs, which can be configured as subwoofer outputs, expand configuration possibilities for setups that require external amplification.

The 19-inch rackmount chassis (442 × 415 × 106 mm, 8 kg) fits into a standard equipment rack. A mounting kit is included. Active cooling ensures stable operation even during prolonged high-volume use. The black finish blends discreetly into a technical environment.

Technical specifications

Amplification

• Configuration: 8 channels / 4 zones
• Output power at 8 Ω: 8 × 100 W (20 Hz – 20 kHz, THD 0.05%)
• Output power at 4 Ω: 8 × 125 W (1 kHz, THD 0.1%)
• Frequency response: 20 Hz – 20 kHz (±1 dB)
• Supported impedance: 4 to 16 Ω
• Bridge mode: yes

Audio processing and settings

• Digital filtering: Marantz Musical Digital Filtering (MMDF)
• Audio modes: stereo, direct, virtual
• Per-zone settings
  • Volume limit: 80 to 100%
  • Balance: –15 dB to +15 dB
  • Bass / treble EQ: –5 dB to +5 dB
  • High-pass filters: 40 to 250 Hz
  • Low-pass filters: 40 to 120 Hz
• Dialogue enhancement: yes
• TV sound grouping: yes

Supported audio formats

• Decoding: Dolby Digital+, Dolby Digital, LPCM, DSD
• PCM: stereo and multichannel
• File formats
  • MP3 / AAC: up to 320 kbps
  • WMA: up to 192 kbps
  • WAV / ALAC / FLAC: up to 24-bit / 192 kHz
  • DSD: 2.8 MHz and 5.6 MHz

Connectivity

• Analog inputs: 4 × stereo RCA
• Digital inputs: 2 × optical (TOSLINK)
• Network inputs: 2 × Ethernet
• USB ports: 4 × USB-A
• Speaker outputs: 4-way binding posts
• Pre-outs: 4 × stereo RCA (convertible to subwoofer outputs)
• Subwoofer outputs: 4 × mono RCA (1 per zone)
• Trigger outputs: 4 × 12 V (one per zone)

Streaming and network services

• Multiroom platform: HEOS built-in
• Streaming compatibility: AirPlay 2, Spotify Connect
• Music services: Spotify, Tidal, Tidal HiFi, Deezer, Deezer HiFi, Amazon Music, TuneIn, SoundCloud, Sony Hi-Res (depending on local availability)
• Network playback: NAS (network share)
• USB playback: FAT32 / NTFS
• Bluetooth: not supported

Control and integration

• Apps: HEOS App (iOS / Android)
• Compatible home automation systems: Crestron, Control4, AMX

Design and installation

• Form factor: 19-inch rack mount
• Cooling: active
• Rack kit included: yes
• Dimensions (W × D × H): 442 × 415 × 106 mm
• Weight: 8 kg
• Finish: black