| Another annoying problem caused by the greatly increased volume of data and vastly higher speeds of transmission was noise. Because of the devices that process data at these high speeds, noise is inevitable. This is like illegal wireless transmissions that interfere with radio reception. However, what is most troublesome is that this is noise we cannot directly hear with our ears, but ultra-high frequency noise residing from 100MHz and upward to the gigahertz range. This noise not only disturbs data communication between each device, but also we can assume its effects on audio devices, and on the control computer inside the car, the very strict worldwide standards. Since operation of the device causes the noise, the noise can be fully stopped by stopping communication by cutting off the switch in the circuit. However, the device can’t function that way, so the only choice is to try to maintain a balance between allowing the noise and continuing operation. Trying to work out this balance resulted in endless days and nights of running simulations and tests and staring forever at the measuring machines. Fortunately, Alpine is equipped with the most advanced facilities for measuring the noise which cars produce, and these facilities demonstrated their superior capacity in these tests.
On the other hand, another major noise problem was that which can be heard by human ears. The problem was a click noise that occurred when functions are switched, as well as a level balance problem after being switched. This is not a simple problem like existing problems of misconnection of volume sections. During the switching process, data communication is performed among the devices, and since we made this multi-functional, an extremely high matching accuracy is required when controlling several system devices at the same time. The remedy for this is to search meticulously for any mis-adjustments of the system among each component. One lesson for me here was that even in the development of the newest digital products, at the final stage, the untiring efforts and steady operations by human beings and the know-how gained through experience is of crucial importance.
Thanks to our efforts we were able to get sound out of the DVD-Audio system on our second system combination test. I can remember being so happy and shouting, “We’ve got sound! I can finally hear the sound of DVD-Audio!” This was the signal that the path to the ultimate sound reproduction was finally open. |
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