Optic Fiber Decoder for Mercedes BMW Audi VW - Keeps OEM Amplifier

In this review of the Optic Fiber Decoder from LEXXSON the bottom line is simple: this adapter is for vehicle owners who want to retain their factory Bose or Harman Kardon optical amplifier when fitting an aftermarket head unit. Installation is straightforward and the product is designed specifically to bridge the optical interface so the original amplifier and speaker system remain functional. For anyone replacing a radio in supported Mercedes, BMW, Audi, Porsche or VW models and who values preserving OEM sound without complex wiring, this decoder delivers that single biggest benefit.

Key Features

• Optical interface compatibility: Keeps the car's original Bose or Harman Kardon optical amplifier working so the factory speaker voicing is preserved.
• Wide vehicle support: Fits many Mercedes models and select BMW, Audi, Porsche and VW models so one unit covers several common retrofit scenarios.
• Plug and play wiring: Cables connect at the front and the grey plug accepts fiber wires, reducing installation time and avoiding splicing.
• Keeps OEM integration: The decoder connects to the can-bus box on the head unit so the new radio integrates with the existing speaker system.
• Low installation cost: By retaining the factory amplifier, workshops can avoid extra amplifier purchases and complex rewiring, saving parts and labor.

Who It's For

The Optic Fiber Decoder is aimed at DIY installers and professional fitters replacing the head unit in Mercedes-Benz R, GL, ML, S W221, CLS and SLK models from the mid 2000s to early 2010s, and for owners of compatible BMW, Audi, Porsche 911/Cayman and VW Touareg models. It is particularly useful for those who want to keep the factory sound signature provided by Bose or Harman Kardon equipment.

It is not intended for cars without an optical amplifier or for stereos that do not provide an optical output; buyers who do not have an OEM optical interface or who want to replace the entire amplifier and speaker setup should look for a full aftermarket amplifier solution instead.

Pros & Cons

Pros

• Preserves factory Bose/Harman Kardon amplifier so speakers keep original tuning.
• Plug and play connectorization simplifies installation and reduces labor time.
• Compatible with a range of Mercedes, BMW, Audi, Porsche and VW models, covering common retrofit needs.

Cons

• Compatibility limited to vehicles with the specified optical systems, so it will not help cars without an optical interface.

Specifications

Product type	Optic fiber decoder / optical box adapter
Brand	LEXXSON
Compatible Mercedes models	R(2005-2018), GL(2005-2013), ML(2005-2011), S W221(2005-2012), CLS(2009-2012), SLK(2009-2012)
Other compatible cars	BMW E9X E7X EOX, Audi 2G/3G HOST, Porsche 911(2004-2015)/Cayman(2004-2016), VW Touareg(2011-2017)
Interface	Optical fiber for Bose / Harman Kardon systems
Installation	Plug and play; connects to can-bus box on head unit

Our Verdict

The LEXXSON Optic Fiber Decoder is a practical, cost-effective choice for anyone replacing a head unit in supported Mercedes, BMW, Audi, Porsche or VW cars who needs to retain the factory Bose or Harman Kardon amplifier. It saves time and expense by avoiding amplifier replacement and integrates via the optical interface, making it a solid value for compatible vehicles while offering no benefit for cars without optical outputs.

Frequently Asked Questions

Will this keep my factory Bose amplifier working?
Yes. The decoder is designed to keep the original Bose or Harman Kardon optical amplifier functional when installed correctly.

Is it plug and play for most installs?
Yes. All cables connect at the front and the grey plug accepts the fiber wires; the unit connects to the head unit can-bus box for integration.

Which cars are supported?
Supported vehicles include listed Mercedes R/GL/ML/S W221/CLS/SLK years, BMW E9X E7X EOX, Audi 2G/3G HOST, Porsche 911/Cayman years and VW Touareg 2011-2017.