I read that the problem with aftermarket car stereo systems is that they are not calibrated to the specific car's interior and interior acoustics but that stock systems are calibrated to the car's interior by the manufacturer. Therein lies the problem with the performance of many aftermaket systems (supposedly). I'm not sure what goes into "calibration." I assume this means the system is tailored to the interior the way we try to get the right speakers and system for a particular room. Is this calibration true or a fallacy? If this is true, are the good aftermarket shops addressing the issue of calibration?