by Tony Whitney
Nowadays, it’s a rare media test car that doesn’t come with a pretty good sound system. Even the least expensive economy cars I try – products in the $13,000 to $16,000 range – seem to have a standard sound system that includes decent AM/FM reception, a CD player and sometimes a cassette system built in too. Some entry level vehicles even include MP3 capability as well.
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Move upmarket a little when you buy a new car and the quality of the sound system keeps pace. Once you get into the luxury segment, you’re likely to get that “concert hall” ambiance with your sound system and for a little more cash, many upscale cars offer an even better stereo experience than the basic system.
I recently gave the sound system in Audi’s new A6 sedan a good workout and it proved to be typical of the type of equipment you can expect in a mid-sized luxury product nowadays. Automakers don’t just choose a sound system and bolt it in place – they tend to work closely with the equipment supplier right from the day the new car takes shape on the drawing board – or to be more accurate, on the computer screen.
Several automakers work with famed sound system manufacturer Bose and that’s the route Audi took when it planned its new A6. The process of developing a sound system for a new vehicle is fascinating and involves all kinds of input from vehicle designers and engineers, audio experts and electronics specialists.
Buyers of Audi A6 sedans can order the Bose Surround Sound System. This delivers what Bose describes as a “synthesized surround sound listening experience” that uses signal processing circuitry developed by the audio company. According to Bose, its signal processing circuitry (dubbed Centrepoint) helps overcome a common problem with high-end automotive surround sound systems – the inability to deliver surround sound from anything but specially encoded CDs and DVDs. What this means is that owners of vehicles equipped with this circuitry don’t have to replace all their CDs with specially encoded ones. The full benefit of surround sound is available from any CD, regardless of whether or not it is encoded. The Centrepoint circuitry automatically processes stereo recordings to produce five independent channels of sound. The result of all this audio technology is remarkable, though typical of the kind of sound you’ll get if you specify the high-end stereo system listed as an option for the new car you buy.
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Of course, developing a sound system that’s capable of getting the best out of your music collection is one thing, but there’s still the problem of where to locate all the speakers. What Bose did (and it’s a process probably followed by other premium sound system makers) was take no less than a thousand acoustic measurements inside the A6 cabin with the idea of matching the surround sound system to the structural and acoustical characteristics of the car. According to Bose, special tools and techniques developed over many years are used for this process.
One problem involved where to put the woofers (low frequency sound speakers) that are essential to all good sound systems. Bose discovered that the best place in the car for these units were the front doors, but as might be expected, the vehicle designers got there first and the recesses were crammed with electronic equipment like door locks and window lift motors. This is a problem that most audio engineers must face these days since even the humblest vehicles often have power windows and locks, not to mention power remote door mirrors.
The answer was developed thanks to a cooperative effort by Bose and Audi engineers. A smaller-than-usual woofer was used, measuring only 13 cm in diameter (Bose calls it “Richbass” for obvious reasons). Despite its size, the woofer generates the sound of a much larger speaker and all you can see of these units in the car are slit-like ports in the door trim panels. Interestingly, Bose hadn’t finished with the front doors when a place was found for the woofers – the tweeters (high frequency sound speakers) and mid-range speakers had to be located there too. At least these speakers were smaller and easier to find room for.
Conventional audio systems usually optimize surround sound only for certain seats in the vehicle, and the front seats, understandably, are usually the target area. Audi’s Bose system, though, gives all occupants the same listening experience – not an easy task when considering that in addition to dealing with internal acoustics, consideration has to be given for a constantly-changing sound environment outside the car.
I found that in the A6, sound seemed to come from areas of the car where there wasn’t a speaker located, which was just what the manufacturer intended. The idea – and the aim of any premium car maker – is to make all the passengers feel that they are in the centre of the music and it’s not just blaring out of a speaker on the dashtop.
Automakers spend a lot of time creating vehicles that are fun to drive and even enjoyable on a busy daily commute. Good sound systems certainly help ease the chore of being stuck in traffic and the right kind of music – played via a good audio system – can have a calming effect on driver and passengers. It’s worth remembering too that most automotive advancements – including those involving entertainment systems – tend to appear first at the luxury level and then filter down to more affordable products. The day may not be too far off when a system like the one Bose designed for the Audi A6 will be available in even an economy vehicle at very reasonable cost.