The final skinny on BOSE HU level outputs

[LukeP]

Okay, I've read things on this forum and in other places on the interweb such as http://forum.M@ZD@6club.com/lofiversion/index.php/t93331.html that go back and forth on what kind of output the 2007 and up BOSE (premium package) head unit provides over it's outputs that go to the bose amp under the seat.

I believe they are actually low level outputs that you can solder RCA cables onto. I used them as high level inputs to my amplifiers and the system works, albeit low volume levels. I measured across the posts with a multimeter and discovered that I was getting 0.48 volts or 480 mV across the +/- of the high level input lines going into my amp while the system was running.

Before I solder some RCA's on and put my amp circuitry in danger I'd just like to put this topic to bed with YOUR help! (thumb) It seems to me if I'm getting a half a volt across there (and the speakers were working quite loudly, full gain and clear) then I should be alright to use the low level inputs as RCA on my amp, which calls for 150 mV to 3V power, no more. High level inputs call for 1-10V according to the instructions on my amp.

 

[LukeP]

I answered my own question this afternoon. Yes, the 2008.5 BOSE premium HU does output low level. I cut an old RCA cable I had laying around in half, and ghetto electrical taped the signal(inside wire) to the + speaker wire I ran, and the ground(outside wire) to the - speaker wire.

I then turned everything down, cut the gain in half, reduced the bass boost and plugged in just one half of the RCA's I planned on connecting. The result? Not only did it work, but there was an unexpected orders of magnitute increase in volume and excursion from the sub. It was already louder and thumping harder than the volume set as high as I dared before, when I had the gain and boost cranked at the amp. If I had left my settings as-was, I would have blown the voice coil through my chest.

After ghettoing up the second RCA and connecting that, It had gotten even louder. Naturally I cut the gain way down, but boy howdy did that ever fix the volume-to-the-rear problem.

 

[Jasnall]

Which wire did you splice your RCA into? Is it one running to the bose amp, or is there one just stickin out the back of the HU.

 

[LukeP]

Right behind the bose HU. There was only a few millivolts going across there, sure enough it was low level. I believe the NON-bose is high level output. Use a multimeter if you're not sure.