Other rear door pictures

1. When removing the rear door panel, note the tab you have to depress to pull the plug out





2.  This is the diameter of the speaker cut out in the door. About 5 1/16".





3. Here's the distance between the two lower speaker frame screw points.About 5 5/8". The distance to the other hole above these was further than my 6" caliper could reach.





4.  Here's a straight on shot of the door with speaker removed. Notice the contours of the door panel. Sealing between the spacer and the door is going to be a challenge.





5.  Here's a side shot of the spacer mated to the door. Note the large gap that we'll have to seal.





6.  I believe that gap is about 1/4". I think I'm going to add foam gasket from both the door and the spacer.

Rear Speaker Measurements

Rear speaker in mount removed from door. Distance between bottom of mounting flange to top of speaker frame. Just under 1.5".

 Measure from bottom of mounting flange to furthest point of speaker. Looks like 2".

So you could bring your speakers forward about about an inch without any worry, probably as much as 1 3/8". The spacers I had made for me were 3/4".
So with my JBL P662s, and the 3/4" spacer, I have about 1/4" more clearance on the window side and 1/8" more clearance on the door panel side.

What wire?

People argue over what size wire you should buy for any application you can think of. Companies want to sell you over-spec'd high-margin products. I believe in buying as much as you need and no more.Both your speaker wire and amp power wire should basically let the current flow and restrict it minimally. Too much current restriction and the wire heats up and can cause component failures (amp) or attenuate the sound (speakers).

Speakers:
This link has a wonderful, lengthy discussion about speaker wire. My take away is that 16 gauge should be fine. I think that 18 would be OK also. I might do 18 to make it easier to run through existing channels. 

Amp:
The manual for the Alpine amp says to use 8 AWG (gauge) power wire, so there you go. I was looking for an Input Current spec as a check, but that seems to be unavailable. 8 AWG sounds like the right thing to do.

Major components

• JBL P662 coaxial speakers for rear
• JBL P660C Component speakers for front
• Alpine MRP-F300 amplifier

High level task order

Essentially you can install the amp or speakers first.

If you install the amp first you get more volume from your stock speakers and you complete the hard tasks earlier. Then when you add the speakers, there's more of a reveal - Amp first is delayed gratification.

If you install the speakers first there's a more noticeable difference right away, but adding the amplifier second puts the harder task at the end of the project- I've always like to get the hard stuff done first.

Speakers first task order:

1. Install front speakers
2. Install rear speakers
3. Wire speakers into existing HU
4. Install amplifier power cable
5. Install amplifier
6. Wire amplifier to HU
7. Wire speakers to amplifier

Amp first task order:

1. Install amplifier power cable
2. Install amplifier
3. Wire amplifier to HU
4. Wire speakers to amplifier
5. Install front speakers (including wiring)
6. Install rear speakers (including wiring)

I have decided to install the speakers first.

The project: Upgrade car stereo

Because I love music, love DIY, spend about an hour in my car daily, and like hands on projects, I thought to upgrade the stereo in my car. When car shopping in 2012 I considered all of the premium sound systems, and none of them were that great. Common knowledge is that you get much more bang for your buck when you purchase and install aftermarket stereo components in your car. So this project represents many things that I love coming together.