The Volvo C70's

When Volvo was deciding the form and ingredients of its C70 coupe and convertible, it looked hard at what the buyers of performance cars wanted. 

Great design, handling and, of course, performance are prerequisites. But in one area, Volvo saw a real opportunity to take things a little further - sound

Best of the Best

Standard car sound systems tend to be of, well, average quality. But average is not a word that can be associated with the C70's audio hardware. Even 'advanced' is underselling things a little. In truth, Volvo scoured the earth for the best of the best. 

The head unit and amplifiers came from Japan's cutting-edge in-car entertainment (ICE) manufacturer Alpine The loudspeakers (10 standard, 12 or 14 optional in the Convertible) were designed and built specially for the C70 in Denmark by domestic hi-fi aesthetes Dynaudio  For the first time ever, California's Dolby Labs Pro Logic surround sound system - developed originally for added soundtrack realism and 'three-dimensionality' in cinema theaters - has been used in a car. 

Demanding Specifications

Car makers cooperating with audio suppliers at the design stage is nothing new, but seldom
have a new model's requirements been so specific and demanding. 

Not only were the speakers made specifically for the C70, crucially so were the panels they are mounted in. 

These have to be rigid and as carefully designed
as the speaker drive units themselves if the full
potential of the system is to be realized. 

Danes Don't Lie (and neither do their
speakers)

Dynaudio, which operates out of the small Danish town of Skanderborg, is a name that will be familiar only to serious stereo fanatics. 

The tiny company produces, in its own words, 'medium to very high quality' equipment, but a better guide to its status is that its cheapest pair of domestic hi-fi speakers, the Contour 1.1, cost $1,425 and the most expensive, the aptly named Consequence, nearly $24,300. 

The company slogan, 'Danes Don't Lie' reflects the slightly obsessive aura of Dynaudio in producing audio equipment that gives as faithful reproduction as is possible. 

Quality Before Quantity

Quality before quantity was the order of priorities Volvo had in mind for C70 owners, so the definition of the typical Dynaudio customer must have been reassuring: 'They know a lot about quality and detail in a tiny scale - and they know about comfort,' says Dynaudio's research and development manager Mark Allan Thorup. 

His young team became excited after hearing that the proposed Volvo system was 'not for a
normal car, but a sports coupe and a convertible'.

Delivering good sound quality in an open-top car is perhaps the ultimate challenge, adding complexity to the decisions about speaker design and location. 

Converting the System

Even with the roof in place, the acoustic properties of the Convertible's cabin are different to those of the Coupe, so the systems fitted to the two cars are, necessarily, slightly different. 

The Convertible has a brace of forward-facing subwoofers behind the rear seats, which boost the bass when the top is down. 

The really clever bit, though, is done with electronics. Perfectly balanced sound is achieved in each with digital sound equalization. 

This automatically selects the correct tone curve depending on the car and, if it's the Convertible, whether the top is up or down. 

Technical Tour de Force

The head unit also boasts the most advanced radio data system (RDS) / radio broadcast data system (RBDS) radio on the market and incorporates an integrated CD player (boot-mounted six-CD changer optional) and an auto-reverse cassette deck. 

In the Convertible, even volume level is adjusted automatically in relation to vehicle speed. 

And there's no danger of running out of power with a choice of 4x60Watt or 4x100Watt power amplifiers. 

Feel The Noise - Literally

The speaker arrays they have to drive are formidable.

In the front there are pairs of eight-inch bass drivers, three-inch midrange units and one-inch tweeters; in the rear 6.5-inch bass/midrange drivers and one-inch tweeters with the option of two nine-inch subwoofers for bass you can feel
as well as hear. 

Then again, if you're not up for the full-on visceral experience, you can switch them off with a special rear seat-mounted control. 

Testing, Testing, 1,2,3...

Initial testing saw Volvo take some likely Dynaudio designs off for their own automotive workout - as anything that goes into a Volvo, whoever it's made by, has to be able to withstand the same tough treatment as the rest of the car. 

Speaker cones have a hard time already; every second of their working lives they have to withstand accelerations of up to 19,000g. 

A moving car is a much more hostile environment than someone's lounge and, unsurprisingly, some modifications were needed. 

Surrounded by sound

We asked Dolby Laboratories in San Francisco,  California, to tell us in their own words how this Pro Logic surround sound stuff works. This is the letter we got back from them. 

'Dolby began working with Volvo and Alpine about two years ago on this project. Based on experiments regarding front sound imaging in car environments we had conducted in 1991 (in an old Volvo test car by coincidence!), we suggested that the system use a slightly modified version of Pro Logic to handle the physical arrangement of front speakers and
front-seat listeners better. 

'While the usual three front speakers are still present just like in the home theater application, in the car system we alter the way the front signals are reproduced to build a center image in front of the driver and the passenger individually, instead of the center image being the center of the dash where the center speaker is placed. The listener senses the central sounds coming
from straight ahead, just as when listening to a normal stereo system. 

'Compared with two-speaker reproduction, the results are that both listeners hear the correct presentation rather than favoring one over the other, and they each hear better frontal imaging than is usually possible in a car system. The surround channel offers a sense of added depth and space. In a car, the background noise is much higher than at home. Low-level recorded ambiance such as hall acoustics would normally become buried in the road noise, causing the music to sound dry or lifeless. Car systems began adding Digital Sound Processors (DSP) to recreate "church" or "hall" modes to help reintroduce the missing spatial details - or just to add some new ones! 

'Pro Logic is essentially extracting ambiance that is part of the original recording and, by reproducing it from separate speakers, allows it to be more easily heard over the road noise, yet does not degrade the intelligibility of the front or dialog sounds, since the ear/brain can discriminate the directional differences - known as the "cocktail party effect" where you can
focus on a conversation in a crowd.' 

Technically Speaking

Radio (SC-900)
Developed in cooperation with Alpine. Very
advanced RDS/RBDS radio with integrated CD
player and auto-reverse cassette deck. Meets
Volvo's requirements regarding safety,
ergonomics, styling, quality and reliability. 

RDS with RT (Radio Text) 
Automatically selects tone curve
depending on which car it is mounted in
(also roof up/down is sensed) 
Prepared for remote control 
Diversity tuner 
Built-in amplifier for the center speaker in
a Dolby Pro Logic surround sound system
Volvo's unique Big Front radio with
anti-theft code/ Can also control optional hide-away six-disc CD changer 

Amplifier 

Available in 4x60W or 4x100W. A development
from Alpine's famous V12 amplifiers. Adapted to this audio system and improved on in several
areas to fulfill Volvo's strict quality and reliability
requirements. 

Duo-beta amplifier circuits 
Fully discreet pre-amp stage 
High current capacity 
Low noise and wide dynamic range 
High-quality selected active and passive
components 

Max output power at 10 per cent THD
4x100W/4x60W 
Output power 4x65W/4x45W 4ohm,
20-20.000Hz, 12V, THD=0.15% 
Signal/noise ratio 103 dB 
Frequency response (+/- 1dB) 30 Hz - 20 kHz 
Channel separation 65dB 
Weight kg 3.5/3.0kg 

Loudspeakers (made by Dynaudio) 

1in tweeter dashboard (Coupe/Convertible) 90W 
4in midrange door (Coupe/Convertible) 50W 
8in woofer door (Coupe/Convertible) 100W 
1in tweeter hatshelf (Coupe) 90W 
8in woofer hatshelf (Coupe) 100W 
1in tweeter rear side (Convertible) 90W 
6.5in woofer rear side (Convertible) 100W 
9in subwoofer rear seat (Convertible, option)
150W 

Center speaker (made by Nokia) 

2in speaker 
(1in tweeter, 5in woofer) 20W 

Crossover filters (made by Nokia) 

3-way door crossover (all cars) 
3-way rear crossover 
(used with optional subwoofer) 

Dolbyô and Pro Logicô are registered trademarks of the Dolby laboratories.