Hey I got an 06 RX 8 with Bose speakers. I'd like to change out the headunit, but the most pre outs I've been able to find is 6. Do they just split the output to the other speakers or is there a 10 (need one for sub) output deck out there?

 

Wire up the front and rear RCA preouts to the Metra kit. The Bose amp takes care of the rest.

And out of curiosity, what headunit were you looking into?

 

Well I've just been looking at the double din ones with the GPS in them. Most I found was 6 outs, so is that what happens to the others? They just get spliced to which ever would work best? I'm trying to see if its worth doing.

It sounds like the Bose system is setup to take the 9 speakers properly where as the aftermarket decks can't take that many speakers without splicing them together. But maybe thats what the Bose deck does anyway

 

The Bose system is not true surround sound, in that, the audio is not separated into its appropriate channels (like a 7.1 home theater). Likewise, the two speakers in the door have completely different purposes. They both receive the same signal, but are then crossed over to only play the appropriate frequencies. They don't really count as two separate locations.

Think about tower or bookshelf speakers in your house. They have multiple speakers, but only receive one signal from the home receiver. Front left for example.

The factory Bose headunit has 4 low-level outputs too. Just like your aftermarket unit.