2000 Mercedes S430..need some help

[baggedon4s]

2000 merceds s430. factory head unit. 5 ch older PPI amp on the highs (all factory highs, center channel is still off h/u) only the front 2 ch are used for the speakers. memphis 1000 pushing 2 alpine 12's. it came to me like this. And I didnt touch any of the settings. The highs sounded like shit. So he wants a memphis 16-6ix and a wired fm mod aux input for a ipad. So I put it in, seems fine, but the sound jumps up and down, on both amps. The factory radio has no numbers to tell you how loud you have it turned up. Thought I was over driving the inputs to the highs amp, so turned the 16-6ix down and turn the highs amp up a bit. All the way up, it sounds great, dosent cut off...but if you mess with the volume control at all,or dont have it all the way up, it will start to get quiet and loud, over and over again. Ive swapped the fm mod twice, moved all the power and grounds from what I did. The old set up worked for 3 years like it was, so figured it was just a simple upgrade. I dont know what is still in the car factory. I dont know if the phone, or what ever is still hooked up in the car, as I didnt do the original install. The car sat for 6 months getting the suspension airbag replaced, and when I got it, the battery was so far gone, when the subs hit, the car would cut off. Replace battery, chased down some engine noise, and now this. What I thought was a hour or two job is now on its 3rd day. It does it either the on the ipod or the radio, same thing. I dont know about the cd, because there is no cartrage in the changer to try it. On the Memphis 16-6ix Iam using just the front and sub inputs and outputs.

Iam out of ideas.

edit, after some research it sounds like a problem with ambient noise feature in the factory bose system.

ok hope the final edit, found the mics in the over head map lights, traced them down and unplugged them, hope it worked, seems to so far