Bose Music System for Audi
TT Coupe and Roadster
According to Audi's own communication material, "The TT first took shape in the minds - or better still, in the hearts - of Audi designers who have retained all their enthusiasm for a truly outstanding car, and who were given as much freedom as possible to translate their concept of 'the way Audi should build a sports car' into reality." As testimony to the long-standing relationship between these two companies, Audi gave Bose a similar degree of freedom in designing the music system "the way it should be built."
This kind of freedom was essential to the success of the Bose music system in the TT. Only by being thoroughly familiar with a car's unique interior dimensions and acoustic properties can Bose ensure the high level of lifelike, spacious sound for which their music systems are renowned. But the more Bose engineers learned about the Audi TT, the more they realized just what a challenge it would be to get the sound they wanted.
Speaker Placement: A Key to Spacious Sound
The most obvious limitation: space. The TT is a compact sports car: fun to drive, beautiful to look at - and a challenging environment in which to provide spacious sound. Yet Bose accomplished just that, partly by managing to fit seven speakers into the Coupe, and eight into the Roadster. This alone was a challenge, even more so when you consider that these speakers had to be placed in proper locations to achieve the desired panoramic soundstage.
The big hurdle to overcome was the acoustic phenomenon compared to most conventional automotive systems known as near-side localization. As Bose engineer Michael Fabry explains it, "In a car you're always sitting asymmetrically, either left or right of center. This means you're always sitting much closer to one speaker than the others. So, unless we do something to counteract it, one speaker will always dominate."
In cars with conventional factory-installed or aftermarket systems, simply adjusting the balance control works fine for the driver. But what about the passengers? Bose seeks to provide spacious sound, with accurate stereo imaging, for everyone in the car.
Bose engineers came up with a two-part solution. One was to place a 2" tweeter in each door roughly six to eight inches lower than the usual tweeter position up near the door handle. These tweeters would work in concert with a pair of Bose 6 ½" wide-range speakers right below them for a full, rich stereo sound. The configuration not only looked good on paper, it fit in with Audi's plans concerning door-handle clearance. So far, so good.
The other half of the solution was a bit more radical: locating a 2" centerfill speaker in the dashboard to improve stereo imaging. Audi knew this would not be easy. As under any dashboard, space is at a premium because of all the electronics that make a dashboard what it is. Compared to most, the TT dash is positively diminutive.
A/B tests on a prototype vehicle made it clear that the system sounded considerable better with the centerfill speaker. Audi engineers, who value quality sound, were determined to find a way to make it happen. The result was, according to Fabry, "the best stereo imaging ever in an Audi vehicle. Voices are properly centered in front of you, whether you're the driver or the passenger."
No Place for Bass?
Next came the issue of bass response. Reproducing bass well is challenge in any automobile. IN the TT, especially so. Because of the characteristics of low-frequency sound, reproducing rich, deep bass means moving lots of air. Traditionally this has meant large, cumbersome woofers that take up valuable space - simply not an option on the TT.
To solve this issue in the Coupe, Bose and Audi engineers worked together to place a 6 ½" woofer in each rear side panel. Key to this configuration were custom-made enclosures which enabled the woofers to deliver bass with just the right amount of impact.
Bottom End with the Top Down
In the Roadster, where the top is down much of the time, good bass is even more of a challenge - one that is compounded by even greater constraints. Custom enclosures containing 6 ½" woofers used in the Coupe would not fit in the rear panels of the Roadster. Instead, Bose engineers placed a 3 ½" wide-range speaker in each panel, and bolstered the bass output by adding a 9" Nd woofer in the trim panel between the seats. Nd speaker technology, a Bose innovation, enables a slim silhouette and light weight - traits unheard of in conventional woofers. The powerful neodymium iron boron magnet has ten times the magnetic energy density of a conventional speaker magnet. This allows for a smaller magnet and innovative positioning of that magnet inside the front of the speaker, instead of its usual position suspended from the rear. Combining high output with a low profile, the Nd woofer delivers rich, deep bass exceptional for its size.
In both the Coupe and Roadster, the results of strategic speaker placement inside the TT provided the necessary foundation for true-to-life sound. So, even in the "cockpit" configuration of this sleek compact car, both passengers are able t enjoy proper stereo imaging and a balanced soundstage that appears much wider than the car itself - a quality of sound similar to what one would hear at a live performance.
Electronics Make the Difference
The design of the Bose music system doesn't end with successful speaker placement. Proprietary Bose signal processing reinforces the panoramic soundstage, so the listener never has to make any adjustments while driving. This level of fine-tuning is made possible with integrated circuit design.
Integrated Bose signal processing automatically adjusts tonal balance to provide natural sound at all volume levels. Music sounds lifelike with full, rich bass at any listening level; speech sounds natural; and the system can reach concert hall levels with no audible distortion.
Active equalization circuitry, custom designed for the TT, provides natural tonal balance and clarity throughout the audio spectrum by electronically balancing the output of all frequencies, at all times. As a result, all occupants can appreciate lifelike musical performance without having to adjust the controls.
Performance that Delights the Senses
Clear in form and distinctive in style, the Audi TT was designed for those who appreciate the pleasures of driving. The Bose music system for both versions of the TT complements those pleasures, providing a stimulating, lifelike soundtrack for traveling the open road.