I'm helping a fellow owner, but his car/approach is waaay different from mine. Hoping for a sanity check on the approach.

The car receiving the upgrade is a Bose/Nav equipped vert. The owner wants to improve the sound without breaking the bank or taking up any additional trunk space. First pass will be upgrading the speakers/power without adding a sub.

I believe he will need to purchase:

1. ADD-GM24
2. 4 channel amp
3. Upgraded front speakers
4. Upgraded rear speakers (optional)
5. Upgraded center speaker (optional)

The ADD-GM24 will need to be modified to add RCA jacks. Accessory power will need to be tapped into for remote turn on for the amp. Power and ground will need to be run for the amp. (with power and ground available for subwoofer amp at a later time if wanted)

Since the stock Bose woofers are going to remain, the stock 4 channel amp has to stay hooked up. This amp will also power the center channel speaker.

New wires will be run to the door and rear speakers. The new amp should have adjustable x-overs to limit low freq's to the door and rear speakers.

Possibly will reverse the front and rear RCAs to limit chime volume, and to allow for "gain" adjustment of the center and rear speakers (C and R speakers will all be off the front RCAs, so fader can be set to rear bias to reduce the output of those speakers). Are woofers driven off of front RCAs or are they fader independent???

Might put 4" speakers in the door to help with any low midrange gaps to the 10" Bose.

Anyone see any issues with these plans? My approach would be a little different... I'd add a sub and amp, and upgrade the 3.5s in the door... But Greg doesn't want to take up space with a sub, so I think this is the next best upgrade.

 

Unplug the center speaker, forget it was ever there.

If you're leaving the door subs, the rest is a waste of money IMO. All you have room for is 3.5" speakers, and it's pointless to buy a new amp for aftermarket 3.5" 2-ways since they don't sell any that can cleanly take much more power than the oem amp can put out. Either replace the twiddlers with 2-ways and call it a day, or dump the door subs and amp a new set of components.

Pin B3 of the add24 will have radio/RAP controlled switched power on it, but it will turn on when you open a door. If you want it to delay until the car is started you can rig a relay and 2 diodes like this.

If you're going to bother with the adjustable crossovers, just go for a digital sound processor, that's really all that the oem HU needs anyway.

 

my opinion... do 6.5 components in doors and ditch bose sub and plan on loosing a little bass but gaining a ton of sound quality. put some deadner in the doors

also ditch the center speaker pretend it never existed

 

Thanks for the input guys.

4" speakers will work. I have some old school MB Quart Q Seriries in mine right now. I was figuring Some JL C2 400's with 50w running them might be an improvement over the stock configuration. Is the stock amp putting out anywhere near 35w? And everyone says bypassing the stock amp with it equalization is an improvement?

Variable crossovers would just be an added bonus to an aftermarket amp, so no cost there.