Is it possible to run all six speakers using a 4 channel amp? Like use two channels for the front speakers then run the back two sets of speakers in parallel using the last two channels?

So is the viso diagram possible, or would I just be better off getting an additional 2 channel amp for the 6x9s?

Oh yeah here are the RMS for the amp:

RMS Power Ratings:
55 watts x 4 chan. @ 4 ohms
75 watts x 4 chan. @ 2 ohms

 

If you are going through the trouble of getting an outboard amp to bypass the Bose amp, you might as well forego the Bose 6x9's and add a real subwoofer in the trunk. Even a modest 10 inch sub will be a significant improvement over the 6x9 "subs". You could power everything with a single 5 channel amp.

I ran front and rear speakers and a 10 inch JL 10w6 in a 4080 box with a JL 500/5 amp.

 

Ya, it is possible. When I originally bought my sound system I had bought 3 amps to power all 6 inside speakers and my 2 subs. I was gonna do an 850.4 for the 2 sets of 6.5 components and a 500.2 for the 6x9's. I was told that the 850.4 "4channel amp" was more than enough to power my 2 sets of 6.5 components and my 6x9 components. Now if you have an underpowered amp which it looks like you do, you may want to buy an additional for the 6x9's. But it is possible for a 4 channel to power all 6 sets. It just needs to be powerful. I hower have 2 Rockford Fosgate Amps for sale. One P8002 $400, and one P5002 $120. Both Brand new still in the box.

 

Thanks Gilley, I never realised that the 6x9s were suppose to be subs. But then again I have only had my car for a month before I went back to Iraq to finish my deployment.

Oh one other question, what is the difference if any between a 10" and a 12" Sub that both have a RMS of 400W same dual 2 ohm voice coils. The only thing that I see on the specs is that the 12" 's sensitiviy is 2 dB higher.

 

Precisely. The 12" subs will hit deeper bass than the 10's will. Have you looked into Zenclosures for a custom made box for your truck? I bought the dual 10" box and it fit perfectly and mitigates sound great. Yea, the factory 6x9's were for mid-base within the car. Alot of people didnt like the factory system which i thought was actually pretty damn nice especially for being factory. Oh well. I replaced all of it anywho. A single sub will def increase sound quality if you ask me.

 

Yes, possible but generally a bad idea.

You could run 7 speakers off a 4 channel amp, but it doesn't mean the amp is going to like it.

You'd be doing one of two things - running the back speakers in series, thereby getting about half the power to twice as many speakers... or running the back speakers in parallel, thereby getting about half as much resistance, i.e. twice as much power, which would likely damage your amp (i.e. if it is 4 ohm stable you'd probably be running it at 2 ohms. not good.)

I agree, ditch the 6x9s and either add a sub amp or swap your existing amp for a 5-channel. I think the JL 500/5 would be a pretty good fit if you're doing a single 10. I picked one of those up for a buddy for $300 and it rocked hard.

 

BTW
Comparing subs based on stats will tell you next to nothing. Sensitivity will generally tell you nothing also. Pay attention to resistance and power handling, but don't be "that guy" and determine what the "best" sub is by what the spec sheet says. Go listen to some stuff at an audio shop eh.