Okay, so the short and sweet of the story is that I've spent the past few weeks looking for information on hooking up a pair of subwoofers with a stock radio, to my dismay I found very very little. ((flashing forward to today)) I received my amp along with my PAC OEM Hon17 RCA converter, after tearing the dash apart in about ten minutes I was getting into the radio finally, I got the PAC oem converter hooked up, ( plugs into the radio and the stock harness plugs into it ) assuming just about everyone knows how to hook up an amp and subwoofer I won't dive into that, at this point I have got two kicker cvr12's and a 1000watt 500rms amp hooked up to them and it sounds amazing. Now, with that said, I WILL need better speakers and perhaps a new h/u in the future, but this is simply due to the fact that the music cannot keep up with the bass. I suppose the main point in all of my jabbering is that the PAC oem converter works like a dream, and the stock h/u isn't necessarily a bad thing with subs. That is all!

 

I plan on keeping my head unit but adding woofers.

 

The stock head unit is designed to make the best of the stock speakers at stock RMS. I too have a line output converter and Ive noticed that the HU is filtering out anything the stock speakers cant play. So if the song your listening to has a low bass note you wont hear it because the HU knows the stock speakers cant play that. You kinda need a aftermarket HU for decent sound.

 

The headunit made the bass sound like crap after about 25 for me. It has a stupid eq setup and should be replaced to get the cleanest sound possible.

 

That's my dilemma as well. I want to keep my OEM navi/headunit. I had thought the line-output converter would solve everything, but I guess not.

Would a sound processor solve for this?

 

You could try one of these:
The Epicenter Plus™ by AudioControl (Gray) Bass processor with aux input for factory or aftermarket systems at Crutchfield.com

My dad uses one of these in his 740i. You can use it in conjunction with a line output converter to restore the bass and increase voltage.

 

I had add a stereo upgrade to the main head unit and it sound just GREAT for me.Check my thread link in my sig for pix....