[How-To] Subwoofer Upgrade - Replacing/Upgrading the Factory Sub

[RagnarKon]

Ok. I guess I am in over my head here. I got the kicker key 500.1 kit from plugnplaykits. I have the power run to the battery and can probably figure out which plug in the b&o amp the kit goes in, but how do I connect to the sub itself? I thought by plug in play it would be ready, but nothing matches up to the green plug on top of the enclosure that goes to the sub. Couple hours in now and super frustrated.

What kit did you buy?

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[foreWard]

Plugnplaykits key 500.1 for the B&o, kit #10

 

[RagnarKon]

Plugnplaykits key 500.1 for the B&o, kit #10

Ah okay. That did doesn't include the cable that goes from the 500.1 itself to the subwoofer.

You'll need to buy these guys:

• Motorcraft WPT-1016
• Extra wire
• Wire crimp

And then wire it similar to how I wired it in this video below. (Starts at roughly 21 minute mark.)

 

[foreWard]

Ok. I had some 12 gauge wire laying around so I just ran speaker wire from positive to positive and negative to negative on the sub, then drilled a hole in the grommet that the oem wires were coming out of and ran a positive and negative through that from the sub to the amp and just bypassed the green plug altogether. She is working now. Might even have too much power, maybe didn’t need to run the parallel circuit, but that’s what google told me to do. A lot of air moving noise now, might see if I can find some sort of gasket to seal the sub to the enclosure now. But anything above about 15% on the bass knob makes a lot of rattly, air slappy noise. But 10% hits pretty good.

 

[mjp2]

Wrap the sub box in sound deadening and really work it into the grooves. It makes a good insulator between the speaker and box itself.

Also cap off the subwoofer box port. It really tightens up the bass and improves the frequency response with an aftermarket speaker.

 

[foreWard]

Wrap the sub box in sound deadening and really work it into the grooves. It makes a good insulator between the speaker and box itself.

Also cap off the subwoofer box port. It really tightens up the bass and improves the frequency response with an aftermarket speaker.

I've seen a couple people talk about sealing the port, is there a "best" way to do it?

 

[mjp2]

I've seen a couple people talk about sealing the port, is there a "best" way to do it?

Best is subjective but I'm biased towards my approach. 3d printed cap secured with plastic bonder like J-B Weld 50133.

It's held strong and doesn't rattle in the least.

Scroll down a bit for pics: https://www.bronco6g.com/forum/threads/mobridge-b-o-stereo-upgrade-installation-video.110747/

 

[foreWard]

Best is subjective but I'm biased towards my approach. 3d printed cap secured with plastic bonder like J-B Weld 50133.

It's held strong and doesn't rattle in the least.

Scroll down a bit for pics: https://www.bronco6g.com/forum/threads/mobridge-b-o-stereo-upgrade-installation-video.110747/

Yeah saw your thread. Great write up. I don’t have a 3d printer. You interested in selling more copies of the cap?

 

[mjp2]

Yeah saw your thread. Great write up. I don’t have a 3d printer. You interested in selling more copies of the cap?

That won't be a problem at all. Send me a DM when you're ready -- it'll be cheap.

 

[MJS76]

Thank you @RagnarKon for giving me the info & confidence to do this project on my 2024 Badlands.

Sorry I didn't take any final pictures after wire management & cleanup complete.

I used the Enfig Car Stereo Kit that comes with everything you need including Custom Wiring Harness (No Splicing Needed), Custom Amp Mounting Brackets, Kicker Key 500.1 Amp, Kicker CompRT 8" Sub, 8ga Fused Power Wire & 8ga Ground.

https://enfigcarstereo.com/product/sub-upgrade-kit-for-ford-bronco-8-sub/

The low end sound produced by this upgrade is easily 3x-4x better than stock.

 

[23OBX2.7]

Thank you @RagnarKon for giving me the info & confidence to do this project on my 2024 Badlands.

Sorry I didn't take any final pictures after wire management & cleanup complete.

I used the Enfig Car Stereo Kit that comes with everything you need including Custom Wiring Harness (No Splicing Needed), Custom Amp Mounting Brackets, Kicker Key 500.1 Amp, Kicker CompRT 8" Sub, 8ga Fused Power Wire & 8ga Ground.

https://enfigcarstereo.com/product/sub-upgrade-kit-for-ford-bronco-8-sub/

The low end sound produced by this upgrade is easily 3x-4x better than stock.

8" can really punch the bass when need more psray that enclosure with a few coats of bedliner or rock guard ro add densiy and add a focal, audison or kenwood 8". I did notice today my steering wheel vibrating lightly and volume wasnt up the much at all...

 

[BroncoCLE]

Thank you @RagnarKon for giving me the info & confidence to do this project on my 2024 Badlands.

Sorry I didn't take any final pictures after wire management & cleanup complete.

I used the Enfig Car Stereo Kit that comes with everything you need including Custom Wiring Harness (No Splicing Needed), Custom Amp Mounting Brackets, Kicker Key 500.1 Amp, Kicker CompRT 8" Sub, 8ga Fused Power Wire & 8ga Ground.

https://enfigcarstereo.com/product/sub-upgrade-kit-for-ford-bronco-8-sub/

The low end sound produced by this upgrade is easily 3x-4x better than stock.

 

[BroncoCLE]

Just so i am clear .. If i buy this kit with Kicker sub and kicker amp. This will retro fit inside my current sub location I will not have to do much but make the hole larger. I can plug n play with currant wires there I do not have run new wires.

 

[MJS76]

You will need to run new 8ga power wire from battery & install new ground at amp & subwoofer location. These are included with the Enfig kit.

I also used Amazon Basics Sound Deadening Mat.

 

[The Samsquantch]

If you watched my last video you will know that I installed the B&O subwoofer. This time I have upgraded that B&O subwoofer with a Kicker 8" sub!

Check below the video for a TON more information that I've collected.

Other videos/guides I've created on the topic of audio upgrades:

• [How-To] Factory Bronco Speaker Replacement
• [How-To] Amp Install - Kicker Key 200.4
• [How-To] FORScan Audio/Speaker Mods
• [How-To] Subwoofer Upgrade - Trim panel removal & Kicker install

AUDIO SYSTEM VARIANTS

As of now (mid-2023) there are four variants of audio systems in the Bronco. How you add/upgrade your subwoofer will depend on which setup you have.

2021 - 2022MY Six-Speaker
This was the audio system that was included in all non-Lux packaged Broncos. There is NO factory subwoofer, nor is any wiring available to support a subwoofer.

2023-2024MY Seven-Speaker
Included in early 2023MY Broncos. This is identical to the 2021 - 2022MY setup, with the addition of an 110 watt amplifier and a 170mm (~6.75-inch) subwoofer.

2023MY Seven-Speaker with Sub Delete
Ford messed up and ran out of subwoofer components. Functionally the same as the 2021 - 2022MY setup. HOWEVER, it contains the wiring and the 170mm enclosure necessary to hook up a subwoofer & amplifier.

2025MY 7-Speaker

For 2025, Ford introduced a new 7-speaker audio system. This audio system uses the A2B digital audio bus similar to the B&O system to pass digital audio between the head unit and the subwoofer amplifier. From a practical perspective, this means you will not be able to remove the factory subwoofer amplifier, as it is the device handling the digital-to-analog conversion. I expect the aftermarket community will introduce new A2B interfaces in the future, which will solve this issue.

2021 - 2024MY B&O
This is the premium audio system included with the Lux package. There are 7 speakers with a single subwoofer measuring 200mm (roughly 8") in size.

2025MY B&O

For 2025, Ford introduced an all-new B&O package with a new audio system. Currently, not much is known about this new system, but once more details are revealed I will be updating this post. That said, the new system much improved and I suspect most people will be happy with the factory setup.

PICKING YOUR SUBWOOFER

At a high level... there are three decisions you need to make when picking a subwoofer:

• Voice Coil Impedance
• Speaker diameter & depth
• RMS power requirements

In addition those three items, there are other specifications such as frequency response, sensitivity, etc. etc. Most people will not have to worry about these items unless they are really trying to optimize their setups. Given I am gearing this post more towards the novice DIY type... I am going to ignore these items. However, you are free to ask questions about these topics or look online. In addition, if any of you car audio pros feel like there is an important aspect I am ignoring... post in in the comments.

Voice Coil Impedance

You will find that subwoofers intended for car audio generally come in two impedance ratings: 2Ω and 4Ω. There is a lot of electrical and power engineering I could dig into, but just to generalize it:

2Ω voice coils will be much louder and more more "boomy", as they can handle more power flowing through the voice coils. Those who dislike 2Ω voice coils often describe it as sounding very "sloppy", while those that like it often describe the bass as very "full" sounding. If you are driving those 2Ω voice coils with an underpowered amplifier, you run the risk of overheating your amplifier and/or creating very "muddy" sounding bass.

4Ω voice coils will have a more tight and clean sound. Uses less power than 2Ω voice coils, and generally more "safer" for underpowered amplifiers. For this reason... if you are running a factory amplifier rather than aftermarket, I generally recommend sticking with 4Ω voice coils. Those who like the sound of a 4Ω subwoofer would describe it as "accurate" sounding, while someone who dislikes 4Ω voice coils will often say it sounds "constrained".

Speaker Diameter

Generally speaking, the bigger the subwoofer the better. BUT, the bigger the subwoofer the more power and space it will require. Unless you are willing to devote your entire cargo space to a subwoofer, most of us will have to come up with some sort of compromise when it comes to the size of the subwoofer.

If you are mounting your subwoofer in the factory location—in the cargo area passenger side panel—you have two sizes available: 6.75" and 8" subwoofer speakers. BUT, there is aftermarket enclosures available—more on this in the enclosure section.

Obviously your subwoofer will need to be able to physically mount inside of whatever enclosure you select. This will be highly dependent on which enclosure and subwoofer you select, and there is a near-infinite amount of combinations available. The only real advice I can give here is "RTFM and measure before buying".

RMS Power Requirements

Obviously you need to pick an amplifier that is capable of powering your subwoofer. More on that in the next section...

PICKING YOUR AMPLIFIER

There is a TON of amplifiers out there in the marketplace. I definitely encourage you to shop around, and gather suggestions from the forum.

One of the more popular amplifiers is the Kicker Key 500.1, which is the amplifier I personally selected—largely because it was compatible with the Plug-n-Play Kit I bought. My brother—who generally knows more than me about car audio—also suggested the Kicker CX series of amplifiers. In my past I would have highly suggested AudioControl amplifiers, but admittedly I have zero experience with their current product offerings.

Arguably the most important part of any subwoofer amplifier is the amount of power it can deliver at a given impedance rating. It's probably easiest to explain this using an example...

Pretend I have selected the following components:

• Amp: Kicker Key 500.1
• Sub: Kicker Comp RT 48CWRT84

The amplifier I have selected has the following specifications. Notice that the maximum power output of the amplifier depends on the impedance rating of the subwoofer.

The subwoofer has the following specifications. Notice the recommended amplifier power is 300 watts. This is the recommended power output when the subwoofer's voice coils is wired in parallel.

What does this parallel business mean?? Well... there is two ways to wire a dual voice coil subwoofer. If you wire subwoofer in parallel, the impedance rating seen by the amplifier is HALF of the value of the voice coil rating. If you wire the amplifier in series, the impedance is DOUBLE the value of the voice coil rating. A 2Ω subwoofer in parallel will cause the amplifier to see 1Ω of impedance. If that same subwoofer is wired in series, the amplifier will see 4Ω of impedance. Wiring diagrams below:

In this case, our subwoofer has 4Ω voice coils, and when wired in parallel, the impedance seen by the amplifier is 2Ω. The Kicker Key 500.1 is rated for 300 watts and 2Ω impedance, which matches the subwoofer's requirements. So we're good to go.

Modern amplifiers are also typically packed with a ton of added features that you may or may not find helpful. Definitely read user manuals, check out reviews online, etc. etc.

SUBWOOFER ENCLOSURE

General speaking there are three choices for subwoofer enclosures:

• Using a powered subwoofer. This has the amplifier, the subwoofer speaker, and the enclosure in a single unit. The Kicker Hideaway series is a popular example of a powered subwoofer.
• Using an external enclosure. This can be as simple as an standard subwoofer box you stick in your cargo area, an enclosure that mounts to your tailgate—such as the Stinger TXFBB12, or even a DIY box you built yourself.
• Mounting it to the factory location. Three options for this:
  • 2023MY+ base audio enclosure - 170mm enclosure (~6.75")
  • B&O enclosure - 200mm enclosure (~8")
  • Aftermarket enclosure, such as the JL Audio Stealthbox.

Personally, I like the factory location as I value my cargo space, but obviously the choice is yours.

Whichever you decide... check your measurements.

HOW TO WIRE YOUR SUBWOOFER AMPLIFIER

Obviously this will vary widely depending on exactly what gear you purchase. So I am going to speak in extreme generalities. If you need help filling in the gaps, let me know.

POWER

Most people will have to pull their amplifier power from the battery, but the 2023 have the option to pull their power from the factory wiring, assuming they have a relatively low-powered amplifier.

VariantPower from BatteryPower from Factory Wiring'21-'22 Six SpeakerYesNo'23+ Seven SpeakerYesYes, but careful (12 ga. wire)'23 Seven Speaker (Sub Delete)YesYes, but careful (12 ga. wire)'21-'24 B&OYesNo

GROUND

Just about everyone will be able to use the ground near the passenger rear cargo area behind the panel. Those with the 2023MY may also use the factory wiring provided, but keep in mind the ground wire should be the same gauge as the power wire or larger (thicker cable).

AUDIO SIGNAL

This is where it gets interesting...

'21-'22 Six Speaker

Those of you in the unlucky 2021-2022 6-speaker camp will have to steal their subwoofer amplifier signal from the left and right kick panel speakers. There really is no other way around it. Of course, certain amplifiers and kits made by companies such as @plugnplaykits can make this task substantially easier for you, but fundamentally it all has to come from the kick panels.

Factory Setup

With Subwoofer Upgrade (Proposed)

'23-'24 Seven Speaker / '23 Seven Sub Delete

2023-2024MY Broncos have all of the wiring in place for an amplifier, regardless of whether you have the sub delete option or not. Upgrades are as easy as taking the old amplifier/subwoofer out (or their fake equivalents), and installing the new amplifier and subwoofer.

Note the 2023MY Broncos with the sub delete option will need to use Forscan to turn on the subwoofer output from the ACM. This output will be a low level (aka: line level) output, not a high level (speaker level) output.

Factory Setup

Factory Setup - Sub Delete

With Subwoofer Upgrade (Proposed)

'21-'24 B&O Package

The B&O package makes it tricky. The amplifier in the rear of your Bronco near the subwoofer is not just a simple amplifier. It is an entire digital signal processor (DSP) that also powers more than half of the speakers in your Bronco. That DSP talks to the factory Audio Control Module (ACM) over a digital connection using a protocol called A2B. Therefore you cannot simply replace the DSP with an amplifier.

There are several companies out there that have aftermarket equipment capable talking on the A2B protocol. BUT, if you are simply going for a factory subwoofer upgrade, your amplifier will have to daisy-chain off of the B&O DSP output.

Factory Setup

With Subwoofer Upgrade (Proposed)

MY PERSONAL SETUP

I have a 2022 Bronco with the standard 6-speaker setup. To feed the subwoofer amplifier I am using a Plug-N-Play kit from @plugnplaykits. That kit steals the signal from the front kick panels, passes it through a load resistor to clean up the signal a bit and give the factory ACM something to look at, and passes it back over the wiring harness to a Kicker Key 500.1.

OTHER THREADS/VIDEOS...

These are thread I've come across that I felt were extremely helpful. If you got one I missed, link it and I'll add it to this list.

Threads

• 2023MY Speaker/Sub Upgrade Megathread
• @jshapz - 2023 7 speaker subwoofer upgrade
• @cmcbronco - B&O sub installed on Base Bronco ….sorta….
• @John P. - John’s 2 Door Badlands Build (B&O Replaced with Active DSP)
• @Ksjrb03 - B&O sound system complete upgrade - Done

Videos

• Kicker Hideaway Powered Sub Install
• @1Five1 Garage - Interior Trim Removal and Soundproofing

FACTORY WIRING DIAGRAMS

IMPORTANT: The wiring diagrams below are for 2022MY & 2023MY Broncos. Absolutely zero effort has been put into verifying their accuracy for other model years, although they are likely to be similar (if not identical).

Hope that was helpful!!!

So I have a 22 with the B&O system and I've been trying to figure how to wire my Skar 1200.1 amp into a Skar VD8 sub. I have a SKE2LOC as well I'm trying to get wired I can't find any information on where to tap into in order to get it working. Tried running my amp power wire and jumping the LOC from it. But I still can't get any power going to it.

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