Hi all,
Been doing lots of reading about this, but stumbled onto something new I can't find an answer to. I recently bought a 98 M3 w/ the HK system. Previous owner upgraded the speakers and headunit with a Kenwood bluetooth cd player. When I got the car and turned things up a bit the back started to sound blown, so I bought new 6x9s and put them in. I noticed he had some aftermarket wires that went into the 6x9s so figured he took care of the wiring behind the scenes. These 4 wires splice into two then go to the 6x9 (ignore the wires on the right, those are for the spoiler brake light)

wires.jpg

I put in these speakers:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Thought they looked good by the reviews. Anyway, started playing them and as soon as I turn the kenwood up to a point where the volume gets just a bit of loudness the rears start to breakup. Like the lose power or something. Cut in and out.

So, start my research. Taking apart the back this is what I discover.

wire mess.jpg

All the rear speakers have been spliced into and then "t'd" off. Just the old 4" speaker wires, not the tweeters. I discovered there were separate wires for the mids and tweeters for the HK rears speakers. Where the old T'd wires went I don't know. I have to assume it went to an amp.

So, I read more, I see people with aftermarket heads bypass the HK amp for rear speakers. This is where my confusions starts. Previous owner didn't bypass the rears, he just spliced into them. I cut them before the amp and ran just the rears' off the old mid's wires to the new 6x9s. Same problem, start to cut out when power gets loud. They should be powered by just the head unit now, correct? The fronts are still being fed by the HK amp as I didn't touch those.

I see previous owner T'd into the mid and still connected through HK amp then took mid and tweeters down to the 6x9s combining them.

I also tried bypassing the mid and tweeters and just ran through the mid wires to the 6x9s from the head unit, same issue.

Sorry this is scattered. Questions I suppose are:
If I'm under powering my new 6x9s from either through the HK amp combined with the Kenwood head, leading to my cutting out? Sound is fine at lower volumes.

If I am and want to fix how do I wire in another amp? Just do what previous owner did? That seems like it still interferes with the HK amp.

If I want to add a small sub I assume do the whole RCA cable deal off the back of the headunit with a dedicated amp, but can I use that same amp (assuming spec work) to power the 6x9 and sub? Even if I need to splice through the HK amp still?

Thanks again, sorry for the rambling. This didn't seem covered in my searches.

Andrew