Okies...(sorry it took a long time for me to reply)...I was sorting something out at work...
So here goes, within the Pioneer Double Din, there is a section under "audio source" or "audio settings" that has the tab "auto Eq". You are now wondering what this does...well the Pioneer double din has the usual settings for Super bass, powerful, natural, vocal, flat and custom 1 and custom 2.
I guess you have tried each one of them and maybe settled for one of it but to be honest none of them would be as great as the one done by the "auto equalizer microphone".
What this does when you connect it is a few minutes process. You connect it and then it tests all the speakers and based on the size of the car and the door panel space it would adjust all the settings. You would then have a beautiful, clear sound from the pioneer system.
Cheers
M