Helix NEXT DSP ULTRA XT

Helix NEXT DSP ULTRA XT – high-end 16-channel stand-alone DSP

The HELIX NEXT DSP ULTRA XT is a stand-alone high-end digital sound processor from Audiotec Fischer, made in Germany. It processes 12 input channels, 8 virtual channels and 16 output channels, each one individually adjustable, and is intended for complex multi-channel sound upgrades. The product received an EISA Award for 2026–2027.

Its signal chain is built around two 64-bit fixed-point audio DSPs, ESS HyperStream IV converters with SABRE technology, Texas Instruments SoundPlus op-amps, thin-film resistors with 0.1 % tolerance at critical points and output coupling capacitors made exclusively for Audiotec Fischer. A 32-bit ACO coprocessor, Virtual Channel Processing, the third-generation ADEP.3 highlevel input, an EV-ready supply range up to 18 V and bidirectional USB PerfectStream round out the package.

Key Features

• 16 processed outputs: 12 input channels, 8 virtual channels and 16 output channels, all processed separately.
• Dual 64-bit DSP: two fixed-point audio signal processors (2 x 295 MHz) delivering 2.4 billion MAC operations per second, with internal processing at 96 kHz / 32 bit and audio bandwidth up to 44 kHz.
• ESS HyperStream IV converters: three ESS ES9841Q A/D converters and two ESS ES9081Q D/A converters, each with its own power supply.
• Premium analog components: TI SoundPlus op-amps in input and output stages, 0.1 % thin-film resistors at critical points and custom output coupling capacitors with optimised dissipation factor.
• ADEP.3 highlevel input: 12 channels accepting up to 32 V RMS, controlled by the ACO platform, designed for compatibility with nearly all factory head units including modern diagnostics, without loading the speaker outputs at high volume.
• USB PerfectStream: bidirectional USB-C connection for lossless streaming up to 192 kHz / 32 bit; individual DSP channels can be sent back to a computer in real time for measurements, and the same connection is used for configuration.
• ACO 32-bit coprocessor: handles control tasks, communication with DSP PC-Tool and fast switching between up to ten sound setups, and runs DLC, RTC, AISA, InputEQ and the sound effects.
• Virtual Channel Processing: for complex routing, with cross-channel group equalisers, multi-way configuration of sound effects and Rear Attenuation.
• Extension Card 2.0 slot: expansion slot for modules such as Bluetooth HD Audio or additional analog inputs, and future modules.
• EV-Ready: operating voltage range extended up to 18 V for use in electric vehicles.
• Start-stop capability: switched power supply keeps the internal voltage stable during drops to 6 V, e.g. at engine start.
• Power Save Mode: switches off the remote output after a period without music signal and resumes in about 2 seconds; the delay can be adjusted or the function disabled in DSP PC-Tool.

Inputs & Outputs

• Inputs: 8 x RCA/Cinch (sensitivity 1–8 V)
• Inputs: 12 x highlevel speaker input (sensitivity 4–32 V) with ADEP.3
• Inputs: 1 x optical S/PDIF (24–96 kHz) and 1 x coaxial S/PDIF (24–192 kHz)
• Inputs: 1 x USB PerfectStream via USB-C (44.1–192 kHz)
• 1 x Extension Card 2.0 slot
• Outputs: 16 x RCA/Cinch with up to 8 V output voltage
• Outputs: 1 x optical S/PDIF (96 kHz)
• Outputs: 1 x remote output (max. 500 mA)
• Smart Control Port (SCP) for remote controls and accessories

DSP & Sound Tuning

• Two 64-bit audio signal processors, 2 x 295 MHz, 2.4 billion MAC operations per second
• Sampling rate 96 kHz, frequency response 10 Hz – 44,000 Hz
• TuneEQ: automated frequency response correction – one measurement per channel or channel pair (e.g. with the AMI Tuning Kit) adjusts the parametric EQ (centre frequency, Q-factor and gain) towards a reference curve
• TuneToTarget and AISA (Advanced Input Signal Analyzer) supported, plus channel-separated InputEQ for correcting signals from OE radios
• Dynamic Loudness Control (DLC) and Remote Tone Control (RTC)
• RealCenter: derives a centre signal from the stereo content of the front left and right channels; the centre stays silent when only one side carries signal
• Augmented Bass Processing: Dynamic Bass Enhancement (subsonic cut-off varies with the input signal) and SubXpander (subharmonics between 50 and 100 Hz)
• Virtual Channel Processing with cross-channel group EQs and Rear Attenuation
• Up to ten sound setups, switchable quickly
• Configuration with DSP PC-Tool 6

Installation & Connectivity Notes

• Operating voltage 9.6–18 V; withstands drops to 6 V for max. 5 seconds (start-stop capable)
• Smart Control Port with integrated power supply for remote controls and accessories
• GND connection switch and Auto Remote Switch
• Operating temperature range -40 °C to +70 °C

Technical Specifications

Scope of Delivery

1 x Signal processor HELIX NEXT DSP ULTRA XT
1 x USB-C cable with USB-A adaptor
1 x Mounting material
1 x Instruction manual