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

Inputs	8 x RCA / Cinch 12 x Highlevel Speaker Input 1 x Optical SPDIF (24 – 96 kHz) 1 x Coax SPDIF (24 – 192 kHz) 1 x Extension Card 2.0 1 x USB PerfectStream (44.1 – 192 kHz)
Input sensitivity	RCA / Cinch: 1 – 8 Volts Highlevel: 4 – 32 Volts
Outputs	16 x RCA / Cinch 1 x Optical SPDIF (96 kHz) 1 x Remote Out
Output voltage	8 Volts
Frequency response	10 Hz – 44,000 Hz
DSP resolution	64 Bit
DSP power	2 x 295 MHz (2.4 billion MAC operations/second)
Sampling rate	96 kHz
DSP type	2 x Audio signal processor
Signal converters	ADC: ESS Technology ES9841Q with HyperStream^® IV architecture and SABRE technology DAC: ESS Technology ES9081Q with HyperStream^® IV architecture and SABRE HIFI^® technology
Signal-to-noise ratio digital input (A-weighted @ 1 kHz)	128 dB
Signal-to-noise ratio analog input (A-weighted @ 1 kHz)	116 dB
Total harmonic distortion (THD+N @ 1 kHz) digital input	<= -110 dB / 0.0003 %
Total harmonic distortion (THD+N @ 1 kHz) analog input	<= -108 dB / 0.0004 %
IM distortion (IMD) @ 1 kHz digital input	<= -102 dB / 0.0008 %
IM distortion (IMD) @ 1 kHz analog input	<= -102 dB / 0.0008 %
Crosstalk @ 10 kHz	> 100 dB
Operating voltage	9.6 – 18 Volts (max. 5 sec. down to 6 Volts)
Power rating	DC 12 V ⎓ 1.2 A max.
Current draw	800 mA
Max. remote output current	500 mA
Operating temperature range	-40 °C to +70 °C
Additional features	Extension Card 2.0 slot, GND connection switch, Smart Control Port, 32 Bit CoProcessor, ADEP.3 circuit, Auto Remote switch, USB-C, USB PerfectStream
Dimensions (H x W x D)	55 x 255.6 x 170 mm / 2.17 x 10.06 x 6.69″

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

9.6V – 18V

Helix NEXT DSP ULTRA XT