Well, I suppose you could have a microphone inside the car and use a reverb model of the car to cancel out the desired sound from each of the car's speakers, but that requires a fair bit more DSP and provides no real benefit over an external mic with an equalizer....:-)
Blaupunkt did this with the New York RCM127 and Bremen RCM127 - as this was their top-of-the-line car stereo, the whole system was heavily based on DSPs, enabling options you had never seen before.
The "Dynamic Noise Covering" option is exactly what you described in your last paragraph. See http://www.blaupunkt.de/fileadmin/user_upload/Service/SERVICEDOKU_ZIEL/BA/GB/7646860010001_BA_GB.pdf , page 54ff, for an explanation. The calibration process took samples of the impulse response and 7-band frequency response with a separate in-car microphone and used that as a reference later.
That was back in 1996. The technology used in their radios is still quite impressive today.
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Well, I suppose you could have a microphone inside the car and use a reverb model of the car to cancel out the desired sound from each of the car's speakers, but that requires a fair bit more DSP and provides no real benefit over an external mic with an equalizer.... :-)
Blaupunkt did this with the New York RCM127 and Bremen RCM127 - as this was their top-of-the-line car stereo, the whole system was heavily based on DSPs, enabling options you had never seen before.
The "Dynamic Noise Covering" option is exactly what you described in your last paragraph. See http://www.blaupunkt.de/fileadmin/user_upload/Service/SERVICEDOKU_ZIEL/BA/GB/7646860010001_BA_GB.pdf , page 54ff, for an explanation. The calibration process took samples of the impulse response and 7-band frequency response with a separate in-car microphone and used that as a reference later. That was back in 1996. The technology used in their radios is still quite impressive today.
D'oh - they should have thought of that much earlier! Get perpendicular - soon also available for SSDs. http://www.youtube.com/watch?v=-xPvD0Z9kz8