New Member
Feb 8, 2020
Atlanta, GA
So I finally decided to upgrade my front door speakers, and let me tell you, I wish I could go back in time and do this years ago. Such an incredible difference even just using the stock amplifier and head unit. I have a 2013 Mustang GT with the ShakerPro Sound system. I upgraded the door kickers to the Shelby Kicker Audio 8" Door Woofers (KA-8-Woofer2010), and the door speakers to the Infinity Kappa 683XF (6x8) series. After 5 minutes of listening to the sound quality, I pulled out the Infinity Kappa 683XF series, and ordered the Infinity Reference 5030cx series. So glad I did. The 683XFs were okay, but missing the high frequency band clarity that the component speaker setup provided. It added some work to cut a hole in the door using a hole saw to mount the tweeters, but honestly only added about 15min to the job. One of the biggest challenges was figuring out which wires to connect to the new kicker as the old one was a dual voice coil (4 wires) and the new was single voice coil (2 wires); I ended up selecting the red wire for positive, and blue wire for negative, the black and white site I just electrical taped off the ends and moved aside. I must have picked the right wires because the audio sounds perfect coming out of the new kickers. I'll walk you through with some pictures below.

Couple of things I ordered before getting started

Ford 2005-2010 Passenger Side Speaker Spacer Bracket
4R3Z-18B947-AA (~$22)
(This part adapts the metal door hole to accept a standard speaker size)

Ford 2005-2010 Driver Side Speaker Spacer Bracket
4R3Z-18B947-BA (~$22)
(This part adapts the metal door hole to accept a standard speaker size)

Scosche Universal Adapter SA68 (~$10)
(This part is just a nice adaptor plate to go from 6x8 opening to 5.25" round for component speaker)

Infinity Reference 5030C - 5 1/4" Two-Way Component system w/crossover (~$200)
(Just my preference of brand, but you could go Polk or Rockford, whatever floats your boat. The crossover is fixed, but it does come with a 3dB tweeter boost if needed; was not needed for my setup)

Shelby Kickers KA-8-Woofer2010 (~$175 w/ shipping)
(Great price given it comes as a 2 pack)

Metra 72-5601 Speaker Wiring Harnesses (~$13)
(Do not use the 72-5600 as the 5601 already accommodates for the wire polarity difference on the 2013 Mustangs. I like these pig-tails as it allowed me to keep the OEM harness in-tact. You'll also need about an extra 10 feet of speaker wire to be able to connect the tweeters and door speaker to the supplied crossover box, and then connect the cross over box to the pig-tail)

So all in all, this project put me about ~$450 in the hole, but like I said, absolutely well worth it and I would spend that money all over again for this level of audio quality improvement. Total install time took me about 1 hour.

Now for the pictures....

Stock front door

Inner panel removed (just look at some YouTube videos on how to remove the panel, its pretty easy)

You can see here the 4 wires going to the kicker, I only used the red and blue. Hooking up all four wires to a single voice coil speaker is NOT recommended.


Here is what the door speaker opening looks like with the adaptor plate to receive any standard 6x8 speaker, so much easier than trying to fabricate an adaptor from the original speaker.

Here is a comparison of the OEM speakers to the new ones (please ignore the fact that I'm comparing to the 6x8s instead of the 5 1/4 component speakers). Those Kappas look great, but I just didn't like the sound (personal preference).


New kicker installed, the Shelby speakers come with a spacer ring, I should have read the instructions better as I'm pretty confident I installed the spacer in the wrong orientation which really made me fight torqueing down the bolts. Pay attention to the little arrow on the spacer

"There are two tabs on the door panel that were used to align the factory speaker. Cut both of those tabs off. The spacer ring has two arrows on it. These arrows MUST be facing up on the door panel. (12 o’clock position) in order for the woofer to install correctly" - Shelby Kicker instructions


Here are the main 5 1/4 speakers from the Infinity Reference 5030cx Series installed. You can see how the Scosche adaptor plate works.


I just used a small hole saw tool on my drill to cut a hole for the tweeter. Recommend going smaller, then using a file to open the hole as needed. Keep a little hand vacuum available, or hand sweep brush, the shavings get a little messy. I mounted the speaker in the only relatively flat clear surface I could find, just forward of the lock/unlock button and as close the the door trim speaker grill as possible (the further you are away from the radius of the trim, the better)


I needed some extra speaker wire to have enough length to go to the pig-tail and to connect both the door speaker and tweeter to the crossover box. I just used some 3M industrial 2-way tape to secure the crossover box behind some trim insulation just rearward of the interior door handle assembly.

I did NOT use the 3dB boost for the tweeters, given their mounting position and given they are pointed towards the passengers, they were plenty bright enough for me.


Here is the final install pic (don't worry, I reattached the window switch later), just got excited to test them out. I absolutely love the way the Reference series sounds on our stock amplifiers coupled with those Shelby kickers.


Honestly, well worth the money to spend, was fairly straight forward. This was the best upgrade option for me as I did not want to have to run new amplifiers, change head unit, or start investing more than $500. The trunk sub sounds so much better to because it isn't being muddled by the OEM kickers any more.

Hope you all enjoyed this write up, feel free to reach out if you have any questions!!
Last edited:


Established Member
Jun 21, 2013
Asheville, NC
I agree the upgraded sound from the Shelby Kicker speakers is well worth it. I created a video on changing out the door speaker to the Shelby 8" Kicker version if it helps anyone as well:


Active Member
Established Member
Sep 27, 2020
I have a 2010 Shaker 500 with Nav, therefore no subwoofer. I think one of the door speakers is going. Can I follow these intructions exactly to upgrade the system since I only have the two rear deck speakers and no rear subwoofer.

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