• H424498
  • DE 29323089

Press & awards



Simply clever – the HELIX SDMI25 is the “smartest solution” to integrate DSP products into vehicles with premium sound system.
In many premium vehicles, the audio signal is embedded in the MOST data stream which enables lossless and interference-free communication between the individual components. The SDMI25 automatically detects the music signal within the MOST25 data stream and outputs it as a highest quality digital stereo signal in SPDIF format. Thanks to its optical digital output, signal processors and DSP amplifiers that are equipped with a digital SPDIF input can be fed with a perfect audio signal.

By simply setting jumpers, the SDMI25 can be adapted to the respective car model. The adjustment of the volume, balance and tone control  via the original radio remains unchanged.
As a special highlight – when used in BMW vehicles – the volume of the on-board warning signals (e.g. of the parking sensors) can be adjusted and thus perfectly adapted in relation to the audio signal.

In various car models the MOST25 components are protected by a serial number. The SDMI25 automatically detects and copies this number from the component to be replaced and finally logs on to the MOST data bus automatically.


  • Interface for generating a digital stereo signal in optical SPDIF format from the MOST data stream
  • Allows an easy integration of a DSP product into modern vehicles with premium sound system
  • Fits in vehicles from Audi, BMW, Land Rover, Lamborghini, Mercedes, Porsche, Volvo and VW. Further information on the vehicle compatibility can be found in our adaptor database
  • Easy vehicle-specific configuration due to jumpers – thus no additional software is required
  • Remote output for switching on and off external components
  • Transmission of all vehicle signals (e.g. parktronic signals)
  • Volume and sound control by original head unit
  • Start-Stop capability down to 6 Volts supply voltage
  • Very compact design for easy integration into the vehicle

Technical data

Input 1 x MOST25
Output 1 x Optical SPDIF (48 kHz / 24 Bit)
Frequency response
10 - 22,000 Hz
Operating voltage
9.6 - 18 Volts (5 sec. down to 6 Volts)
Dimensions (H x W x D)
34,60 x 62 x 102 mm;
1.36 x 2.44 x 4.02"



Scope of delivery

1 x SDMI25
1 x Mounting material
1 x Instruction manual

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