My stereo build! JL Stealthbox, Focal K2s, etc..

OnTheReel

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Since all the loose ends are now tied up I figured I’d share my system and hopefully give others some ideas / inspiration / tips / whatever. This is a 2021 with the Alpine system. I will just go in the general order I put the stuff in and a follow up post with links to the main things I used.

The amps:
On the driver’s side cab wall, I made an amp board out of HDPE that piggybacks off the active dampening module’s mount. There is a lot of depth in this corner because the E-Torque battery lives there in normal Rams. On this board I mounted a JL VX600/6i which runs the front and rear doors, and dash corners. This is a 6 channel amp with 8 channels of DSP. It is 75w/ch into 4 ohms and 100w into 2 ohms. The front door speakers are 2 ohm and make use of the added power.

For the passive 7th and 8th channels of DSP from the VX600, I installed a very compact and simple MTX MUD50.2 amplifier. This amp runs the roof speakers, set up as fill and just to brighten things up back there since the bass is so strong. They are at a level where I can’t much hear them from the driver’s seat. So they don’t screw with the imaging but certainly make it sound nicer for the rear passengers.

The finished driver’s side board. Spacing the VXI HUB on standoffs allows the cables from the VX600/6i to pass underneath. Tried to be as tidy as possible while realizing this is 10 pounds of shit in a 5 pound bag:
4A77EB5A-E9DF-4DDA-AA2F-91E5561E9530.jpeg


In the factory sub’s location I made another amp board which holds a JL VX1000/1i. This is a 1000w monoblock amplifier that runs the JL Stealthbox.

C4399859-651B-4BEC-80E5-2553916DA625.jpeg
This amp is networked to the VX600 via a JL VXI Hub so they can be tuned simultaneously as well as both controlled by the JL DRC-205 bass knob. The outer knob controls sub volume, the inner knob is main volume. There is also a push button that allows you to cycle through pre-set tunes you can create. The knob lights up whatever color is tied to the preset. I only have two setup right now. There is my main setting, and one I put together for listening at lower volumes with I have company. It cuts the tweeter levels and boosts the midrange frequencies (much like the stock system did), as these are often diminished by road noise. Which would leave the system sounding a bit tinny at lower volumes. Both presets have time delay and some EQ applied. And obviously crossovers.

Initial setup via the JL TUN 4 app:
36C22C82-8206-4AE5-842A-7B6B2A639848.jpeg

Whilst doing the amp boards I fully deadened the back wall with SoundSkins Pro. I shot for almost full coverage and painstakingly unclipped each wire hanger and module. And later played a game of memory to find all the holes after. This is an overview photo before everything was 100%:
592D23A0-58A7-40C3-9EA4-3F219409801B.jpeg

The power:
This is simple enough. Starting in the engine compartment, I cut a strip of ABS plastic and heat bent to mount alongside the battery using existing bolts. A Kicker AFS fuse holder was then mounted to that. The wire was wrapped in loom and Tesa tape, run through the nipple in the firewall, down the sills in the factory channel, and then back to a dual fuse holder on amp board #1. From there each amp gets it’s power. Grounds use stock locations along the cab floor, under the carpet.

The signal:
The key to the whole operation is the PAC AP4-CH41. This provides pre-amp outputs AND a remote turn on from the stock system. In my case, I also added the TOSLINK adapter (APA-TOS01) to this module. This allows me to run a single optical cable back to my amp instead of bulky (and noisy) RCAs. There is absolutely no hiss using this connection and no gain setting either!!!

To install the PAC module, you have to pull the display out and plug it into the tuner. I ran the PAC’s cable down to the driver’s footwell. This leaves the module accessible for service and updates without having to pull the screen again. While not difficult, it’s an uncomfortable process that I don’t care to do again. From the PAC module, I ran my optical and remote turn on cables down the same channel as the power wire and bass knob to the amp board. The optical plugs into the JL VXI hub which allows the two amps to communicate and be tuned and controlled as one. Out of the hub there are optical cables for each amp, and Ethernet cables for each amp. The MTX amp is fed via RCA preouts on the VX600/6i. And that completes the signal section from start to finish.

The PAC module was ultimately secured with Velcro. It is extremely tight up there and they don’t give you much wire to work with:
7730D430-6E0B-4A5A-B486-85AAB7833BFF.jpeg


The speaker connections:
All the new speakers are installed with Metra adapters. There are some funky polarity things going on with these systems stock so I did take the time to check all the speakers are moving in the same direction when I was done. With the VXi amps, I can swap polarity electronically which really made things easy.
To marry the new amp(s) to the existing speaker wiring, the cleanest and easiest solution is to use a T harness. No wires to cut! For this project I used the PAC APH-CH03. This harness plugs in at the amplifier under the drivers ‘s seat and gives you speaker wire pigtails that you can hook up to the corresponding wires coming from the new amplifier.

In the CH03’s package, you get what amounts to 3 separate harnesses. The ANC bypass is the simplest as it’s just plug and play. It effectively disconnects the mics, so while the ANC remains “online”, it does nothing. This is necessary when you’re swapping door speakers powered by the stock amplifier. In my system, all of the speakers involved with the ANC system are being powered by my 6 channel amp, so there was no need to bypass.
The other two harnesses handle your speaker connections. The one with the small connector handles the front doors and front dash in the Alpine system.

The bigger speaker harness handles everything else…rear doors, sub, center channel, roof, and the upper front doors in the HK system. In this harness you will connect together (by color) any channels you want to remain powered by the factory amp. Any wires for speakers that are NOT being powered by the factory amp can be de-pinned at the amp-side of the PAC harness. If deleting the factory sub, you can de-pin those on both sides as well. This just gives a cleaner and smaller harness.

The speaker connections under the seat tuck away nicely:
B717DE23-37E4-4A8E-A927-97EE499CA764.jpeg

To connect the speakers and run back to the amp, I used speedwire. Makes things very easy, 4 channels in one jacket. Since I needed 8 channels, I ran two sets. This cable is quite bulky and would never fit in the wire channel under the door sill. So I ran it around the Ram Bin and under the carpet. I then soldered and heat shrunk every connection to the amp pigtails.
4C70F1D0-294D-4AC4-95B8-18C1FAB9C06F.jpeg


The speakers:
In front I am using a set of Focal K2 Power (ES 165KX2) as an active front stage.
469962E0-BC9B-49EE-91BC-1107DCC5503D.jpeg

The 6.5” 2 ohm woofers are installed into the front doors with HDPE adapters and SoundSkins speaker rings to direct the energy out of the grilles.
0153A899-526B-4270-A4A5-1204CCCC1BB6.jpeg

The Focal KX2 tweeters are installed in the dash corners in a similar manner with adapters and speaker rings.
C90697CD-1C1F-43C6-8C8E-B01A342A394A.jpeg

For the rear doors, I have an older set of Focal K2 power 165KRC. These are 6.5” coaxial speakers with external crossovers I have mounted to the inner door plate.
CBD49204-6D18-43B8-85BD-DA6157AD121E.jpeg

All doors are deadened with the SoundSkins Pro on the skin, as well as spot treatments on the black plastic panel, and some on the flats of the inside of the door panels.
8A830AB8-4FD1-4D98-8B8A-0F6F5EFF653F.jpeg

Lastly, to bring the roof speakers into play, I have some older Focal K2 tweeters that I had from a previous install.
91902671-8723-40B7-A413-B20F389C5EDF.jpeg

The sub is the JL Stealthbox for trucks with reclining seats. It has two 10TW3 subs in a fiberglass box that totally blends in and disappears. The underseat storage was lost but the RamBins are still fully accessible.
051F0D80-D4D8-4F2B-90FF-266FC92548EE.jpeg


When installing everything, I used almost 4 rolls of SoundSkins Pro between the doors and cab back wall. Also used some cheaper/ lighter materials on the back floor, and around the RamBins. The truck was already very quiet for what it was and this only improved things. I do not miss the ANC system one bit. If I can find a way to quiet door the air vents on the back wall, it’ll be perfect but even as it is, it’s very impressive. Doors close with a solid thump. And even though I had it all apart, I have no rattles, even at volumes too uncomfortable for anyone to listen to. The truck is well made and all of the plastics are nice and durable. If you’re worried about taking things apart and breaking things or introducing rattles, don’t worry. Take your time and it’ll be better than you found it when you’re done!

As I listen to the system I will continue to make changes to my taste. But as it stands, it’s pretty damn good. First, it’s ridiculously loud and dynamic. The Focal tweeters are unbelievably clear but not harsh at all after getting the levels set right and pulling down some peaky frequencies. The mids of course are tight and strong. And the Stealthbox has enough balls to distort the rear view camera mirror image at high volumes; it really does it’s thing for just two 10s. Overall the system fits the truck. Loud, fun, stupid, expensive and unnecessary.
 
The stuff I used. List is not exhaustive and I didn’t buy everything from Crutchfield. While I wanted a really great system for all the work I planned to put in, I did cut costs wherever possible. That includes buying on eBay, using stuff I had lying around from other systems, and Crutchfield open box deals on the amps. Conservatively trimmed a grand off retail. Doing the work myself also saved thousands in labor. The process easily took a total of a full week of full days. It was spread out doing stuff as my business and weather permitted.

Interfaces:
PAC AP4-CH41 R.2

https://www.crutchfield.com/p_541AP4CH41/PAC-AmpPRO-AP4-CH41-Aftermarket-Amplifier-Interface.html

PAC APH-CH03

https://www.crutchfield.com/p_541APHCH03/PAC-APH-CH03-AmpPro-Harness.html

PAC APA-TOS01

https://www.crutchfield.com/S-jpv9Vqxrq6M/p_541APATOS1/PAC-APA-TOS1.html

Speakers:
Focal ES 165KX2 (front)

https://www.crutchfield.com/S-LImkbsgt3At/p_091ES165X2/Focal-ES-165KX2.html

Focal K2 Power 165KRC (rear)

https://www.crutchfield.com/S-fAjGU1GHaLF/p_091165KRC/Focal-K2-Power-165KRC.html

JL Stealthbox SB-D-5GRAMCCR/10TW3 https://www.crutchfield.com/S-ffahfVTyFLC/p_13694677/JL-Audio-Stealthbox-Black.html

Amps:

JL VX600/6i

https://www.crutchfield.com/p_13698639/JL-Audio-VX600-6i.html

JL VX1000/1i

https://www.crutchfield.com/p_13698631/JL-Audio-VX1000-1i.html

JL DRC-205

https://www.crutchfield.com/S-hgL6tlTnM2S/p_13698128/JL-Audio-DRC-205.html

JL VXI HUB

https://www.crutchfield.com/p_13698411/JL-Audio-VXi-HUB.html

Deadening:

SoundSkins Pro Mega Kit

https://soundskinsglobal.com/products/soundskins-pro-mega-kit?variant=12467835437098&currency=USD
 
Nice work man, I was just getting ready to post my build and came across this. Love it and congrats again on the Loud, fun, stupid, expensive and unnecessary toy!
 
Dude, wow! I can appreciate all the time and money you put into that! Nice!
 
Since all the loose ends are now tied up I figured I’d share my system and hopefully give others some ideas / inspiration / tips / whatever. This is a 2021 with the Alpine system. I will just go in the general order I put the stuff in and a follow up post with links to the main things I used.

The amps:
On the driver’s side cab wall, I made an amp board out of HDPE that piggybacks off the active dampening module’s mount. There is a lot of depth in this corner because the E-Torque battery lives there in normal Rams. On this board I mounted a JL VX600/6i which runs the front and rear doors, and dash corners. This is a 6 channel amp with 8 channels of DSP. It is 75w/ch into 4 ohms and 100w into 2 ohms. The front door speakers are 2 ohm and make use of the added power.

For the passive 7th and 8th channels of DSP from the VX600, I installed a very compact and simple MTX MUD50.2 amplifier. This amp runs the roof speakers, set up as fill and just to brighten things up back there since the bass is so strong. They are at a level where I can’t much hear them from the driver’s seat. So they don’t screw with the imaging but certainly make it sound nicer for the rear passengers.

The finished driver’s side board. Spacing the VXI HUB on standoffs allows the cables from the VX600/6i to pass underneath. Tried to be as tidy as possible while realizing this is 10 pounds of shit in a 5 pound bag:View attachment 40667

In the factory sub’s location I made another amp board which holds a JL VX1000/1i. This is a 1000w monoblock amplifier that runs the JL Stealthbox.

View attachment 40668This amp is networked to the VX600 via a JL VXI Hub so they can be tuned simultaneously as well as both controlled by the JL DRC-205 bass knob. The outer knob controls sub volume, the inner knob is main volume. There is also a push button that allows you to cycle through pre-set tunes you can create. The knob lights up whatever color is tied to the preset. I only have two setup right now. There is my main setting, and one I put together for listening at lower volumes with I have company. It cuts the tweeter levels and boosts the midrange frequencies (much like the stock system did), as these are often diminished by road noise. Which would leave the system sounding a bit tinny at lower volumes. Both presets have time delay and some EQ applied. And obviously crossovers.

Initial setup via the JL TUN 4 app:View attachment 40683
Whilst doing the amp boards I fully deadened the back wall with SoundSkins Pro. I shot for almost full coverage and painstakingly unclipped each wire hanger and module. And later played a game of memory to find all the holes after. This is an overview photo before everything was 100%:View attachment 40669
The power:
This is simple enough. Starting in the engine compartment, I cut a strip of ABS plastic and heat bent to mount alongside the battery using existing bolts. A Kicker AFS fuse holder was then mounted to that. The wire was wrapped in loom and Tesa tape, run through the nipple in the firewall, down the sills in the factory channel, and then back to a dual fuse holder on amp board #1. From there each amp gets it’s power. Grounds use stock locations along the cab floor, under the carpet.

The signal:
The key to the whole operation is the PAC AP4-CH41. This provides pre-amp outputs AND a remote turn on from the stock system. In my case, I also added the TOSLINK adapter (APA-TOS01) to this module. This allows me to run a single optical cable back to my amp instead of bulky (and noisy) RCAs. There is absolutely no hiss using this connection and no gain setting either!!!

To install the PAC module, you have to pull the display out and plug it into the tuner. I ran the PAC’s cable down to the driver’s footwell. This leaves the module accessible for service and updates without having to pull the screen again. While not difficult, it’s an uncomfortable process that I don’t care to do again. From the PAC module, I ran my optical and remote turn on cables down the same channel as the power wire and bass knob to the amp board. The optical plugs into the JL VXI hub which allows the two amps to communicate and be tuned and controlled as one. Out of the hub there are optical cables for each amp, and Ethernet cables for each amp. The MTX amp is fed via RCA preouts on the VX600/6i. And that completes the signal section from start to finish.

The PAC module was ultimately secured with Velcro. It is extremely tight up there and they don’t give you much wire to work with:
View attachment 40671

The speaker connections:
All the new speakers are installed with Metra adapters. There are some funky polarity things going on with these systems stock so I did take the time to check all the speakers are moving in the same direction when I was done. With the VXi amps, I can swap polarity electronically which really made things easy.
To marry the new amp(s) to the existing speaker wiring, the cleanest and easiest solution is to use a T harness. No wires to cut! For this project I used the PAC APH-CH03. This harness plugs in at the amplifier under the drivers ‘s seat and gives you speaker wire pigtails that you can hook up to the corresponding wires coming from the new amplifier.

In the CH03’s package, you get what amounts to 3 separate harnesses. The ANC bypass is the simplest as it’s just plug and play. It effectively disconnects the mics, so while the ANC remains “online”, it does nothing. This is necessary when you’re swapping door speakers powered by the stock amplifier. In my system, all of the speakers involved with the ANC system are being powered by my 6 channel amp, so there was no need to bypass.
The other two harnesses handle your speaker connections. The one with the small connector handles the front doors and front dash in the Alpine system.

The bigger speaker harness handles everything else…rear doors, sub, center channel, roof, and the upper front doors in the HK system. In this harness you will connect together (by color) any channels you want to remain powered by the factory amp. Any wires for speakers that are NOT being powered by the factory amp can be de-pinned at the amp-side of the PAC harness. If deleting the factory sub, you can de-pin those on both sides as well. This just gives a cleaner and smaller harness.

The speaker connections under the seat tuck away nicely:View attachment 40673
To connect the speakers and run back to the amp, I used speedwire. Makes things very easy, 4 channels in one jacket. Since I needed 8 channels, I ran two sets. This cable is quite bulky and would never fit in the wire channel under the door sill. So I ran it around the Ram Bin and under the carpet. I then soldered and heat shrunk every connection to the amp pigtails.View attachment 40674

The speakers:
In front I am using a set of Focal K2 Power (ES 165KX2) as an active front stage. View attachment 40675
The 6.5” 2 ohm woofers are installed into the front doors with HDPE adapters and SoundSkins speaker rings to direct the energy out of the grilles.
View attachment 40676
The Focal KX2 tweeters are installed in the dash corners in a similar manner with adapters and speaker rings.View attachment 40679
For the rear doors, I have an older set of Focal K2 power 165KRC. These are 6.5” coaxial speakers with external crossovers I have mounted to the inner door plate.View attachment 40678
All doors are deadened with the SoundSkins Pro on the skin, as well as spot treatments on the black plastic panel, and some on the flats of the inside of the door panels.
View attachment 40680
Lastly, to bring the roof speakers into play, I have some older Focal K2 tweeters that I had from a previous install. View attachment 40682
The sub is the JL Stealthbox for trucks with reclining seats. It has two 10TW3 subs in a fiberglass box that totally blends in and disappears. The underseat storage was lost but the RamBins are still fully accessible.View attachment 40681

When installing everything, I used almost 4 rolls of SoundSkins Pro between the doors and cab back wall. Also used some cheaper/ lighter materials on the back floor, and around the RamBins. The truck was already very quiet for what it was and this only improved things. I do not miss the ANC system one bit. If I can find a way to quiet door the air vents on the back wall, it’ll be perfect but even as it is, it’s very impressive. Doors close with a solid thump. And even though I had it all apart, I have no rattles, even at volumes too uncomfortable for anyone to listen to. The truck is well made and all of the plastics are nice and durable. If you’re worried about taking things apart and breaking things or introducing rattles, don’t worry. Take your time and it’ll be better than you found it when you’re done!

As I listen to the system I will continue to make changes to my taste. But as it stands, it’s pretty damn good. First, it’s ridiculously loud and dynamic. The Focal tweeters are unbelievably clear but not harsh at all after getting the levels set right and pulling down some peaky frequencies. The mids of course are tight and strong. And the Stealthbox has enough balls to distort the rear view camera mirror image at high volumes; it really does it’s thing for just two 10s. Overall the system fits the truck. Loud, fun, stupid, expensive and unnecessary.



Nice Job!!
 
Just dropping some other pics I didn’t have room for.

Fuse holder under hood. Green things are moth balls for the asshole squirrels that tried to make a home in here.
B5263190-C2AB-48C8-B6F3-DE440F0E0C9C.jpeg


Bass knob location. I really like it here and it was super easy to install:
FE3AE57A-C8C9-447C-ADBD-E2FF5FE88AFF.jpeg


The radio module the PAC plugs into:
0CC100EA-740D-4C4C-B186-8DA3B058DBDE.jpeg


These are a couple of the rivnuts I used to hold the sub amp board (in addition to a top bracket I made). These holes initially held wire clips, so I put new holes in the amp board to reattach them right next door.
F1F57730-8E0D-4D27-8A9A-BFA31DBF436C.jpeg


This was the first (and easiest) piece of sound treatment I installed. I couldn’t believe the factory didn’t use anything throughout the whole wall, and only very thin strips in the doors. Obvious cost cut vs my previous GM trucks.
9FBA87DB-309E-492E-87F5-54753FE23AC4.jpeg


Some spot treatment I did on the floor with a cheaper 2 in 1 product I had left from my 442. I also did around and inside the RamBins.
3B16DF74-EE05-413C-BAC5-D2F70BF28CFB.jpeg
 
Just dropping some other pics I didn’t have room for.

Fuse holder under hood. Green things are moth balls for the asshole squirrels that tried to make a home in here.
View attachment 40756

Bass knob location. I really like it here and it was super easy to install:View attachment 40755

The radio module the PAC plugs into:
View attachment 40754

These are a couple of the rivnuts I used to hold the sub amp board (in addition to a top bracket I made). These holes initially held wire clips, so I put new holes in the amp board to reattach them right next door.View attachment 40753

This was the first (and easiest) piece of sound treatment I installed. I couldn’t believe the factory didn’t use anything throughout the whole wall, and only very thin strips in the doors. Obvious cost cut vs my previous GM trucks.View attachment 40757

Some spot treatment I did on the floor with a cheaper 2 in 1 product I had left from my 442. I also did around and inside the RamBins.View attachment 40759



There are few people I would trust to upgrade the audio on my TRX and you clearly would be in that small group! Congrats on an extremely professional and complex project! This is very, very similar to what I have planned...I have always loved a stealthy look with OEM (or better) fit & finish.
 
There are few people I would trust to upgrade the audio on my TRX and you clearly would be in that small group! Congrats on an extremely professional and complex project! This is very, very similar to what I have planned...I have always loved a stealthy look with OEM (or better) fit & finish.
Thank you! Good luck with your build, I look forward to seeing it. And don’t hesitate to reach out if you have questions on anything.
 
Thank you! Good luck with your build, I look forward to seeing it. And don’t hesitate to reach out if you have questions on anything.



Are you by chance also into high-end home audio?
 
Not really, I just rock out in the truck. Never fell into the home audio or home theater rabbit holes.



They are very fun but expensive rabbit holes!
Both have been good business models for us over the past 22+ years...
 
Thank you! Good luck with your build, I look forward to seeing it. And don’t hesitate to reach out if you have questions on anything.

Curious - I see the Focal KX2 has a 120 RMS while the VX600 only has a 100 RMS at 2 ohms. How does this sound and do you wish you went with a 120 RMS amp?
 
Curious - I see the Focal KX2 has a 120 RMS while the VX600 only has a 100 RMS at 2 ohms. How does this sound and do you wish you went with a 120 RMS amp?
Main reason I went with the KX2s over the K2s were the bigger tweeters, even though the woofers are also rated slightly higher in power handling.

Ultimately, JL amps are always a bit underrated, and I couldn’t see wanting more volume (or more anything). That said, I’m sure the speakers could take a lot more juice if you wanted to push it. I’ve run the same or more power through way worse speakers. Hell, before I did the doors I was putting that 100+w RMS through the stock 6x9s for a couple days. 😂
 
Since all the loose ends are now tied up I figured I’d share my system and hopefully give others some ideas / inspiration / tips / whatever. This is a 2021 with the Alpine system. I will just go in the general order I put the stuff in and a follow up post with links to the main things I used.

The amps:
On the driver’s side cab wall, I made an amp board out of HDPE that piggybacks off the active dampening module’s mount. There is a lot of depth in this corner because the E-Torque battery lives there in normal Rams. On this board I mounted a JL VX600/6i which runs the front and rear doors, and dash corners. This is a 6 channel amp with 8 channels of DSP. It is 75w/ch into 4 ohms and 100w into 2 ohms. The front door speakers are 2 ohm and make use of the added power.

For the passive 7th and 8th channels of DSP from the VX600, I installed a very compact and simple MTX MUD50.2 amplifier. This amp runs the roof speakers, set up as fill and just to brighten things up back there since the bass is so strong. They are at a level where I can’t much hear them from the driver’s seat. So they don’t screw with the imaging but certainly make it sound nicer for the rear passengers.

The finished driver’s side board. Spacing the VXI HUB on standoffs allows the cables from the VX600/6i to pass underneath. Tried to be as tidy as possible while realizing this is 10 pounds of shit in a 5 pound bag:View attachment 40667

In the factory sub’s location I made another amp board which holds a JL VX1000/1i. This is a 1000w monoblock amplifier that runs the JL Stealthbox.

View attachment 40668This amp is networked to the VX600 via a JL VXI Hub so they can be tuned simultaneously as well as both controlled by the JL DRC-205 bass knob. The outer knob controls sub volume, the inner knob is main volume. There is also a push button that allows you to cycle through pre-set tunes you can create. The knob lights up whatever color is tied to the preset. I only have two setup right now. There is my main setting, and one I put together for listening at lower volumes with I have company. It cuts the tweeter levels and boosts the midrange frequencies (much like the stock system did), as these are often diminished by road noise. Which would leave the system sounding a bit tinny at lower volumes. Both presets have time delay and some EQ applied. And obviously crossovers.

Initial setup via the JL TUN 4 app:View attachment 40683
Whilst doing the amp boards I fully deadened the back wall with SoundSkins Pro. I shot for almost full coverage and painstakingly unclipped each wire hanger and module. And later played a game of memory to find all the holes after. This is an overview photo before everything was 100%:View attachment 40669
The power:
This is simple enough. Starting in the engine compartment, I cut a strip of ABS plastic and heat bent to mount alongside the battery using existing bolts. A Kicker AFS fuse holder was then mounted to that. The wire was wrapped in loom and Tesa tape, run through the nipple in the firewall, down the sills in the factory channel, and then back to a dual fuse holder on amp board #1. From there each amp gets it’s power. Grounds use stock locations along the cab floor, under the carpet.

The signal:
The key to the whole operation is the PAC AP4-CH41. This provides pre-amp outputs AND a remote turn on from the stock system. In my case, I also added the TOSLINK adapter (APA-TOS01) to this module. This allows me to run a single optical cable back to my amp instead of bulky (and noisy) RCAs. There is absolutely no hiss using this connection and no gain setting either!!!

To install the PAC module, you have to pull the display out and plug it into the tuner. I ran the PAC’s cable down to the driver’s footwell. This leaves the module accessible for service and updates without having to pull the screen again. While not difficult, it’s an uncomfortable process that I don’t care to do again. From the PAC module, I ran my optical and remote turn on cables down the same channel as the power wire and bass knob to the amp board. The optical plugs into the JL VXI hub which allows the two amps to communicate and be tuned and controlled as one. Out of the hub there are optical cables for each amp, and Ethernet cables for each amp. The MTX amp is fed via RCA preouts on the VX600/6i. And that completes the signal section from start to finish.

The PAC module was ultimately secured with Velcro. It is extremely tight up there and they don’t give you much wire to work with:
View attachment 40671

The speaker connections:
All the new speakers are installed with Metra adapters. There are some funky polarity things going on with these systems stock so I did take the time to check all the speakers are moving in the same direction when I was done. With the VXi amps, I can swap polarity electronically which really made things easy.
To marry the new amp(s) to the existing speaker wiring, the cleanest and easiest solution is to use a T harness. No wires to cut! For this project I used the PAC APH-CH03. This harness plugs in at the amplifier under the drivers ‘s seat and gives you speaker wire pigtails that you can hook up to the corresponding wires coming from the new amplifier.

In the CH03’s package, you get what amounts to 3 separate harnesses. The ANC bypass is the simplest as it’s just plug and play. It effectively disconnects the mics, so while the ANC remains “online”, it does nothing. This is necessary when you’re swapping door speakers powered by the stock amplifier. In my system, all of the speakers involved with the ANC system are being powered by my 6 channel amp, so there was no need to bypass.
The other two harnesses handle your speaker connections. The one with the small connector handles the front doors and front dash in the Alpine system.

The bigger speaker harness handles everything else…rear doors, sub, center channel, roof, and the upper front doors in the HK system. In this harness you will connect together (by color) any channels you want to remain powered by the factory amp. Any wires for speakers that are NOT being powered by the factory amp can be de-pinned at the amp-side of the PAC harness. If deleting the factory sub, you can de-pin those on both sides as well. This just gives a cleaner and smaller harness.

The speaker connections under the seat tuck away nicely:View attachment 40673
To connect the speakers and run back to the amp, I used speedwire. Makes things very easy, 4 channels in one jacket. Since I needed 8 channels, I ran two sets. This cable is quite bulky and would never fit in the wire channel under the door sill. So I ran it around the Ram Bin and under the carpet. I then soldered and heat shrunk every connection to the amp pigtails.View attachment 40674

The speakers:
In front I am using a set of Focal K2 Power (ES 165KX2) as an active front stage. View attachment 40675
The 6.5” 2 ohm woofers are installed into the front doors with HDPE adapters and SoundSkins speaker rings to direct the energy out of the grilles.
View attachment 40676
The Focal KX2 tweeters are installed in the dash corners in a similar manner with adapters and speaker rings.View attachment 40679
For the rear doors, I have an older set of Focal K2 power 165KRC. These are 6.5” coaxial speakers with external crossovers I have mounted to the inner door plate.View attachment 40678
All doors are deadened with the SoundSkins Pro on the skin, as well as spot treatments on the black plastic panel, and some on the flats of the inside of the door panels.
View attachment 40680
Lastly, to bring the roof speakers into play, I have some older Focal K2 tweeters that I had from a previous install. View attachment 40682
The sub is the JL Stealthbox for trucks with reclining seats. It has two 10TW3 subs in a fiberglass box that totally blends in and disappears. The underseat storage was lost but the RamBins are still fully accessible.View attachment 40681

When installing everything, I used almost 4 rolls of SoundSkins Pro between the doors and cab back wall. Also used some cheaper/ lighter materials on the back floor, and around the RamBins. The truck was already very quiet for what it was and this only improved things. I do not miss the ANC system one bit. If I can find a way to quiet door the air vents on the back wall, it’ll be perfect but even as it is, it’s very impressive. Doors close with a solid thump. And even though I had it all apart, I have no rattles, even at volumes too uncomfortable for anyone to listen to. The truck is well made and all of the plastics are nice and durable. If you’re worried about taking things apart and breaking things or introducing rattles, don’t worry. Take your time and it’ll be better than you found it when you’re done!

As I listen to the system I will continue to make changes to my taste. But as it stands, it’s pretty damn good. First, it’s ridiculously loud and dynamic. The Focal tweeters are unbelievably clear but not harsh at all after getting the levels set right and pulling down some peaky frequencies. The mids of course are tight and strong. And the Stealthbox has enough balls to distort the rear view camera mirror image at high volumes; it really does it’s thing for just two 10s. Overall the system fits the truck. Loud, fun, stupid, expensive and unnecessary.
There should have been a disclaimer “Don’t try this at home”
 
Not sure how I missed this build earlier in the year… very nice work!
 
Main reason I went with the KX2s over the K2s were the bigger tweeters, even though the woofers are also rated slightly higher in power handling.

Ultimately, JL amps are always a bit underrated, and I couldn’t see wanting more volume (or more anything). That said, I’m sure the speakers could take a lot more juice if you wanted to push it. I’ve run the same or more power through way worse speakers. Hell, before I did the doors I was putting that 100+w RMS through the stock 6x9s for a couple days. 😂
What size power wire did you run and any issues with fitting?
 
What size power wire did you run and any issues with fitting?
Knukonceptz Kolossus 4 gauge. It’s rated a bit higher than a normal 4 gauge so I went with it to gain a little more headroom. The max theoretical draw between the two amps is 130, and the Kolossus 4 can handle up to 150 amps at the length I used.

Running 4 gauge was pretty easy, no major snags. 0 gauge would be an absolute nightmare, if not completely impossible. I’d sooner run two 4 gauges to be honest. Not a lot of room in the wire channels along the sills.
 
i replaced all factory speakers also with FOCAL and Digital Designs subs,,, makes the"alpine" system rock :)
 
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