I have an '05 G35 Coupe. I am going to use the factory radio/amp, and am just swapping speakers and adding some Dynamat.

I have researched this, but am trying to simply confirm two things:

!, the amp is indeed running at 2ohms, so a standard 6 1/2" component speaker set (already running at 2ohm such as the Infinity Kappas) should go right in without getting to the amp or any other hardware/wiring, correct?

2, what is the true, factory size of the rear speakers (6 1/2" or 6" x 9")?

I am thinking I can just get the Kappa component set up front and the rear speakers (whatever size they are), and since the amp supposedly runs at 2ohms, they'll all drop right in with no headaches...

Can you believe the dealer, local shops, Crutchfield.com--no one can answer these q's without tearing the car down? I see where many posts talk about the Bose amp being 2ohms, but some people are running 6 1/2" in back whereas others have 6"x9" back there...I'm just looking for ease of install...

 

If you are going to change out the speakers then change out the amp at the same time. The stock amp sucks!!!! A good amp with a low THD can be had for little money these days. Just use the factory wires and you can intercept them at the bose unit. That's what I did and I'm running 170w RMS per speaker with an aftermarket amp and it sounds good. The stock amp will not run Infinity's to the point where they will be appreciated. I'm running Focal Utopia's with an aftermarket amp and a sub with 900w RMS to it so I just took out the factory 6x9's. There are 4 speakers in the rear. 6.5's in the floor area and 6x9's in the rear dash.

 

So, there are 4 speakers back there on the coupe's parcel shelf???

The Infinity's were a cheap option, and certainly, if I were gonna run Focals I'd go all out, but was just trying to spend about $500 and keeping everything simple...

 

i spent a little over 300$ and i got two 10 fosgate punch stage 2's and a box and amp...why spend 500$ to replace the stock bose....get some bump .....and i still have plenty of trunk space

 

Because the mids and hi's still sound muddy even with the bass turned all the way down. There are only two speakers on the rear shelf. The other two are below the B-pillars.

 

Are the 6x9's subs or are they full range speakers as well (or vice versa w/ the b-panel 6.5"s)???

 

The 6x9's in the rear tray are "subwoofers" according to Bose.

 

So, I can essentially still get the 2ohm Kappa components up front, the 2ohm coaxes for the rear pillars and leave the stock 6x9 subs and it should still sound a lot better, no???

 

Just upgrading the front and rear speakers should give some improvement in the sound.

 

Welp, I did it:

I bought the Infinity Kapps 60.7CS components as well as the 62.7i coaxials for the rear. However, after dropping in the front components as well as adding dynamat to the doorskins, the sound stage was so improved and proper, that I skipped even bothering with the rears. I find the balance perfect from my driving position with the proper full range fill from the stock rear speakers. The Infinity's were 2ohm and dropped right in with no issue. The sound is soooo much better than stock!

ps: If anyone needs coaxes, I'll give them a great deal!