HARMAN has brought together its extensive knowledge of the Professional, Automotive and Consumer business areas and its many years of experience in sound tuning, uniting these elements in the brand new AuraVox software-supported equalizing system for use in cars. AuraVox is breaking new ground in perfect in-car sound coordination, permitting a level of computer-based adjustment hitherto unimaginable. Above and beyond purely mathematical parameters, HARMAN has also brought its profound knowledge of acoustics and psychoacoustics, subjective sound perception and highly complex system integration to bear on AuraVox development.
When they come to integrate sound systems in cars, sound engineers are confronted with extremely complex architecture in greatly confined spaces. Even the most precisely positioned high-end loudspeakers will only reveal their full potential through careful acoustic tuning. For decades now HARMAN's specialists have been dedicating themselves to this tough task which demands an extraordinary degree of talent and experience. The authentic listening experience that meets HARMAN's stringent quality standards can only be achieved by adjusting the sound to the individual vehicle type and music system on hand.
The sound engineers use equalizing to compensate for the tiniest irregularities and resonances in frequency response: frequencies that are too loud or too soft for the human ear are adjusted with the utmost care. The requisite harmonious sound is only achieved when the frequency response of all channels has been coordinated.
The reflections within the car itself are a further challenge: A wide variety of materials, ranging from seat covers and paneling to the windscreen sit cheek-by-jowl in a very confined space. The multiplicity of reflective properties needs to be teased out for each channel in order to achieve perfect sound quality.
In the final analysis, the sound engineers need to compensate acoustically for the proximity of the seats to the loudspeakers and the varying distances to the individual sound transducers. Harmonious sound and the impression of spatial depth are only achieved if the runtime differences of a few milliseconds are perfectly adjusted to a uniform level simultaneously in all seat positions.
When it comes to sound tuning, HARMAN uses a total of 24 microphones to measure the entire vehicle interior using specially developed software and hardware. Each speaker in the car transmits a pulsed response to all microphones. This corresponds to 384 pulsed responses in a modern high-end music system with 16 active sound transducers, found in premium class limousines, for example.
In the past, the large number of acoustic influences meant that sound engineers had to adjust hundreds of parameters manually. The specialists at HARMAN defined more than ten filters per channel in order to achieve the required frequency response pattern. AuraVox uses the extensive measurements to create the appropriate filters automatically, correcting run-time differences and regulating the optimum volume levels of the individual channels in advance. The pioneering AuraVox technology has been continuously optimized over the years and has now reached a level of perfection that enables an impeccable auditory experience.
HARMAN has invested five years in developing AuraVox, aiming to support the multi-layered, challenging task of sound tuning with a computer-based application. Development involved 35 system and sound engineers, acoustic specialists, mathematicians and physicists with up to 15 years of experience in the fine-tuning process. The result is a highly specialized instrument that performs a number of important basic functions when the sound system in a new car is measured. AuraVox enables computer engineers to carry out around 80 percent of coordination tasks with computer support. This takes only a fraction of the time a sound engineer usually needs to adjust a sound system to the interior of a vehicle.
This leaves a lot more time for the final fine-tuning necessary for a faithful music experience. After it has been tested using the latest measurement techniques, the sound system has to satisfy the ultimate arbiter of perfect music pleasure: the human ear. The talent and experience of the HARMAN sound specialists decide on the ultimate acoustic that the system develops in a new vehicle. The final sound must always match the high Harman Kardon standard, but may feature fine nuances – depending on the particular car model and the relevant target group. Only if the "golden ears" of the Harman Kardon acoustic experts are well and truly convinced of the quality of reproduction will the premium sound system be used on the road.