Making the MOST of your car

Making the MOST of your car

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Media Oriented Systems Transport

MOST is a protocol for the transfer of digital information around a car. Defined first in 1998, MOST is by no means new yet, it has not been in the consciousness of the consumer until now and even then, only for a few keen technophiles. Founded as a result of cooperation between manufacturers of in car electronic systems and automotive companies amongst others, MOST pointed the way toward a future of cost efficiency and technical compliance, not previously seen in the the world of automotive manufacturers. MOST is used largely to transfer audio, video and other high-speed digital information around a car. The advantage of having a standard protocol for this was seen in instant savings,  development costs and time required to meet the requirements du jour of automotive manufacturers. The development of MOST made it relatively cheap and simple to provide equipment that could simply be plugged in and work.

Initially, many manufacturers of aftermarket in car entertainment products felt MOST development had a hidden agenda, to lock out the possibility of modification to the audio systems on cars. However, the availability of this protocol has actually helped them to produce MOST compatible products which can also plug and play! There is a caveat to this which we mention later.

Anyone who has taken a car to a franchised dealer with a three-year-old broken car audio unit will know how disinterested car companies are in sorting out your problem. Many who have tried, report astronomical figures to get original equipment replaced or repaired. Allegedly, this situation even led to criminal damage as thieves attempted to fill the void of working replacement original equipment by nicking them from parked up vehicles!

So, as you can see, far from locking aftermarket companies out of vehicles, the widespread adoption by motor manufacturers of a readily available digital protocol has helped the aftermarket to develop products which can replace aged broken equipment in say a BMW or Mercedes.


Automotive aftermarket technologists and owners of high-end car audio brands Audison and Hertz were quickly on the case with MOST. Audison had already perfected methods of taking high-level speaker inputs directly from speaker outputs. They had with equal alacrity, developed systems for nullifying on-board equalisation and other contrivances intended to make very cheap speakers sound almost musical. However, they quickly identified that it was the conversion of signals from the digital domain to analog that was causing much of the stale sound that was appearing at the outputs. They set to work to find the purest most digital route to convey audio signals directly into their amplifiers, where far better quality digital to analog conversion could be managed.

bit DMIlg

One such product to tumble out of their research is the Audison bit DMI (Digital Music Interface). This device is able to collect audio signals directly from a vehicle’s MOST bus and convert them to a standard TOSLINK optical digital output. This can then be used to inject the pure digital signal directly into a bit processor for cleaning up or simply directly into the A to D convertor of an Audison amplifier with digital inputs.

So, now for the aforementioned caveat. Although MOST is a defined protocol for the dissemination of digital data, the coding within this data is still in the hands of the car manufacturer and its audio supplier. This means that although a connection can be made very simply and data intercepted, it is quite likely that some form of decoding will be required. Audison achieve this by way of regular compatibility firmware updates. Heavy sigh’s all round? Not necessarily as this coding is not kept particularly secret and can be resolved accurately and reasonably quickly by the clever people at Audison and other companies who use this technology. However, it is always worth consulting with an expert such as a FOUR MASTER, when interfacing with your vehicle’s MOST bus as they have the products and also the knowledge to save you from jumping into a very deep hole!

If you want your music rendered digitally, visit a FOUR MASTER as soon as you are able and discover whole levels of sound you have never experienced in a car or even at home before!


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