Helix M Four DSP (M – Series)

HELIX M FOUR DSP

Pure HELIX Sound – No Compromises

At the heart of the M FOUR DSP lies a high-performance 64-bit fixed-point DSP from Analog Devices and top-tier 32-bit AD/DA converters by AKM. Together, they deliver uncompromised sonic purity and precision. The German-engineered DSP board and six 6V RCA preamp outputs ensure clean signal transmission, ready to drive any add-on amplifier with authority.

Bridgeable, Flexible Amplification

The internal 4-channel amplifier can operate in:

• 4-channel mode
• 3-channel mode (bridged + 2 channels)
• 2-channel bridged mode

With its six preamp outputs, the system can expand to 10 fully processed audio channels, making it ideal for building complex, space-saving systems when combined with other M Series amps like the M ONE, M ONE X, M FOUR, or M SIX.

Virtual Channel Processing – Modern Routing Simplified

HELIX’s Virtual Channel Processing (VCP) revolutionizes how signal routing works:

• Create logical signal chains independent of physical I/O
• Simplifies integration with complex OEM systems
• Ideal for building advanced multi-way setups
• Allows full use of HELIX FX features: RealCenter, Augmented Bass Processing, StageXpander, and more

Configuration is a breeze using the intuitive DSP PC-Tool software.

ACO – Speed and Intelligence Redefined

The Advanced CoProcessor (ACO) handles all control and monitoring tasks:

• Enables lightning-fast switching between 10 DSP presets
• Offers ISA (Input Signal Analyzer) and InputEQ for quick and accurate input signal calibration
• Supports future firmware updates, ensuring compatibility with evolving OEM diagnostics
• Boosts communication speed with the DSP PC-Tool

Smart OEM Integration – Designed for Modern Cars

ADEP.3 Smart High-Level Input

Avoids common OE head unit issues like:

• Diagnostic error messages
• Loss of fader or balance
• Speaker overload at high volume

Thanks to ADEP.3 (Advanced Diagnostics Error Protection, Gen 3), the M FOUR DSP integrates cleanly and safely into modern vehicles with high-level signals.

Start-Stop Capability

Keeps the amplifier running even when battery voltage drops to 6V during engine cranking.

Power Save Mode

Reduces energy draw after 60 seconds of inactivity by shutting off remote outputs. Reactivates instantly upon signal detection. Fully configurable via DSP PC-Tool.

Compact, Efficient, and Cool

Despite its extensive power and feature set, the M FOUR DSP maintains the classic HELIX compact chassis, perfect for stealth installations. Class D efficiency ensures it runs cool, while the design aligns perfectly with other M Series models.

Feature Highlights

• Up to 135W RMS per channel @ 4Ω/2Ω
• 64-bit Audio DSP with 32-bit AKM AD/DA converters
• 10 fully processed DSP channels
• Six RCA outputs (max. 6V) for external amps
• Bridgeable channels for flexible subwoofer/woofer configurations
• ACO – Advanced CoProcessor for fast DSP switching and smart features
• ISA & InputEQ – For OEM signal analysis and correction
• FX Suite – Includes RealCenter, Augmented Bass Processing, StageXpander
• ADEP.3 high-level input – Advanced OEM integration
• Power Save Mode – Low-power standby behavior
• Start/Stop Ready – Works with modern vehicle electrical systems
• DSP Board made in Germany

Advanced DSP Features

TuneEQ – Automated Precision Tuning

Just one measurement per channel pair with a mic like MTK1 allows automatic EQ optimization using a reference curve. Fully utilizes parametric EQ (frequency, Q-factor, gain) in the background.

RealCenter – True Center Imaging

Rather than simple summing, RealCenter dynamically adjusts based on stereo content to avoid distortion and maintain a natural, wide sound stage—ideal for both driver and passenger seats.

Augmented Bass Processing

Delivers massive low-end enhancement through:

• Dynamic Bass Enhancement: Adds depth and punch at low volumes without overloading subs at high volumes.
• SubXpander: Adds subharmonics between 50–100 Hz for a darker, deeper bass experience.