Hello,I have a 2005 coupe with the Bose sound system. A few years ago I replaced the head unit with an Atoto Series 8 Android based head unit. I have the Atoto back up cam with a yellow RCA jack and the front recordable dashcam. I have been pretty much happy with it but the Android Auto requires the USB cord. Not very reliable and frustrating when you miss the exit because it disconnected. ( I just found about a wireless device to fix that problem) Close to a year ago my driver side window would power go down almost all the way but the last 3-4 inches. I took the door panel off and Bose 10" speaker out and saw the wire harness was in a position that prevented the window from going 100% down. I zip tie the cable out of the way and put everything back together. I didn't realize the speaker connection didn't click into place. Weeks, maybe a couple months later the bass in the driver door was failing. Bumps would turn off or on the bass on the driver side only. I thought maybe it was the factory amp was starting to fail. Then more recently no bass. So I went to 2 different audio shops to talk about what was going on. My take away was to put back in the factory stereo and see if I have the same result. So I did and had no bass on the driver side door. BUT it was much louder even with the driver side main speaker with no bass. I didn't realize it was not working due to it not being plugged it. I reinstalled the Atoto thinking the amp or the speaker failed. I was going to swap left and right door speakers tonight to see if the problem would follow the speaker. Tonight I took off the door panel and saw the speaker connector was not plugged in. I previously heard sound because the door tweeter was working. So I plugged it back in and turned on and turned on some music. Speaker worked fine, more bass. I was pretty excited now that I have full music sounds again.When turning it up to maximum volume it seems to go flat, not a new problem. I can turn it almost to max volume and it sounds good but at max it get a little quieter and seems to go flat. Not sure how to describe it.Again it is an Atoto Series 8. I hope I am going to try installing the factory head unit again the weekend to see if it does the same thing with going flat at max volume or rocks. Last night when I have the factory head unit in, it was rocking even with the driver side not working.So if it performs better than the Android like I am suspecting what head unit works best with the factory Bose system? I don't want to spend thousands of dollars for music. I would rather spend thousand on go fast parts. 😁I am thinking to replace the Atoto head unit with something else that work well with the factory amp and speakers.Thanks

 

Any of the big name brand head units will fine. Look at Kenwood, Pioneer, Alpine, Sony, etc.

 

Get rid of that cheap Atoto head unit, and buy a brand name head unit like Fred mentioned. What interface are you using ?

 

I am not sure what you are referring to by "what interface I am using?'

 

Well in order to install an aftermarket head unit correctly requires the use of an interface, the most commonly used one on this forum is the PAC RP5-GM11 as shown here. https://www.crutchfield.com/p_541RP5...Interface.html

 

Ahh, yes I have a PAC something, little blue box I soldered wires to for the factory wiring harness to plug into. I installed the it a couple years ago and don't remember the model number.

 

Here is an update to what I found.

About a year ago my driver side window was not rolling down 100%. Staying up about 3 inches. I needed to remove the door panel and 10" Bose subwoofer from the door. I found the wire harness got hung up under the window in the down position preventing the window from going all the way down. I zip tied the harness out of the way and reassemble everything.
I must not have secured the connector very well to the speaker because I found the speaker was not connected. The connector was just hanging there disconnected. This time I plugged it back in and made sure it clicked together.
ALL is good now. Maybe I will replace the head unit, but not sure at the moment.
Thanks everyone.