Car audio options explained

Negotiating the options list of any new car can be a daunting but exciting task with a multitude of extras on offer to enhance the comfort, looks and function of your new vehicle.

Among the range of options including upholstery, trim, equipment and styling packages, more brands are offering premium audio systems as part of the enhancement – and often at a hefty price.

Here is the WhichCar guide to premium car audio terminology and features, and what the extra investment gets you.

Brands

Some major home entertainment brands also offer car-specific technology, and many work with a major car marque so that advances in home entertainment can be enjoyed on the road.

Among others, Mark Levinson provides systems for Lexus, Bose has worked with many manufacturers including Nissan, Mazda and Skoda, Harman Kardon gear can be found in BMW models, high-end Audis have adopted Bowers and Wilkins and Bang and Olufsen, Dynaudio is a relatively recent addition to Volkswagen, Infinity has created systems for Hyundai, Meridian kit graces some Jaguars, Mcintosh is associated with Subaru and Bermester is the preferred high-end stereo for Mercedes-Benz.

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Amplifier and channels

Optional upgraded audio systems often list the type of amplifier that is supplied including number of channels. As the name suggests, the amplifier or ‘amp’ is an audio signal booster that increases the power of a stereo allowing it to drive more speakers, and make their output louder.

But with power comes control and a stronger speaker signal also reduces distortion for a clearer sounding, higher quality output.

The number of channels does not relate to channels in the sense of radio or television, but refers to the number of amplifier outputs and how many speakers can be driven. The higher the number, the more speakers there are and the broader the sound range and volume.

Channels are sometimes described by two numbers separated by a decimal point. A 12.2 system has 12 speakers and two subwoofers.

What are watts?

The electrical power of a system is measured in watts. Put simply – the more watts, the more powerful the output. For context, a very basic small car sound system might have about 50 watts, while the most expensive options in large cars can approach 1000 watts. Custom installations built by enthusiasts using aftermarket components can be engineered with many thousands of watts.

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Speakers

With more amplifier channels, an entertainment system can use a broader range of speakers for a greater audio range. High frequency sounds are reproduced by tweeters, bass is handled by larger low range speakers and subwoofers, while the mid-range is looked after by mid-range speakers.

Tweeters are normally located close to the occupants and in line of sight as upholstery and obstructions can deaden high-frequency sound. The sound from subs, on the other hand, can permeate the entire cabin so can be hidden away.

If a stereo system lists an uneven number of speakers, it usually means a single subwoofer is included.

Very high-end systems can include novelty features such as ornate tweeters that rise out of the dashboard, and speakers with inbuilt ambient illumination.

Surround sound

This innovation is an evolution of stereo sound, and uses more a sophisticated system and more speakers placed about the cabin to create a sense of greater depth in the sound.

Dolby is a name given to proprietary technology that may be available in other vehicles but under a different name. Dolby’s technology includes surround sound as well as other reproduction technology, including stereo.

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Active noise cancelling

Another relatively recent automotive application, noise cancellation was first applied to military aircraft. The clever system plays the exact inverse sound wave of ambient noise caused by tyres and wind, relaying it through the stereo speakers. The two opposite sounds actually cancel each other out.

It might seem strange that playing additional sound through a speaker might help improve cabin ambience but the systems can be very effective.

Equaliser

While more budget audio systems often offer bass, treble and mid-range adjustment, higher end options usually offer a full equaliser or graphic equaliser.

Rather than just three parameters, an equaliser allows the user to customise the sound quality depending on the type of music being played, or just personal preference.

DAB+ digital radio

Digital audio broadcasting or DAB replaces traditional analogue radio broadcasting for more reliable signal without the hiss associated with a poor analogue reception. The format also allows extra information to be sent with audio transmissions such as displaying the name of the artist on the screen of your entertainment system.

DAB+ provides a more reliable coverage in areas within broadcasting range and also supports MPEG Surround sound for greater depth of sound. However, because it is a digital system, it won’t slowly fade out like an analogue system when the signal starts to weaken. Instead, it will either work … or not.