Updated: Subwoofer install for 9-speaker system (GT) and solving the "buzz"

[DCBuckeye]

Heavily edited this original post to reflect the final build and process.

Hi all. I've been closely reading the various threads on here about modifications to the audio systems, specifically the subwoofers, and watching anything I can on Youtube. That said, I've never done any work on a car audio system before, so I was a little nervous as I get ready to tackle this. The below reflects the end results of my research and steps I took to install a subwoofer on a GT Premium with the 9-speaker system (not B&O and no factory subwoofer).

So, as you can see, my basic plan was:
1. Tap the wiring harness going to the rear speakers, and feed that into the Kicker KISLOC2 line output converter.
2. That goes to the amp, and amp to speaker.

I had originally planned to mount the amplifier to the subwoofer box with some rubber isolation washers, but I decided against that as I wanted to be able to remove the subwoofer from the trunk without having to disconnect the power and ground wires for the amp.

Power line from the battery to the amp was run through a gasket located behind the passenger-side wheel well. It was a bit of a pain to get in there; I took the tire off and opened up the cover for the wheel well, then used a utility knife to carefully slice an opening, then fed a wire hanger through and taped the power cable to it before pulling it back through the gasket.

The line output converter I'm using is the KISLOC2 LOC. It has a remote wire that will turn the amp on or off depending on whether there is power to the rear deck speakers, so that means I won't need to tap a fuse for on/off. Downside is apparently the mustang's rear deck speakers (perhaps all of them) power on when you approach the car with your keyfob, so there will be a few "thumps" from the subwoofer. I like to think of it as a heart beat. That said, I've confirmed the LOC and the subwoofer do turn off after a couple minutes you turn off and walk away from the car.

Update 6/29/24: I swapped out the cruddy Autotek amp for an Alpine and the sound is much improved. I did finally notice the buzz that some other folks have reported while cruising, so I loaded up Forscan and took a look. Using this super helpful post (thank you @roket ). I was 99% certain the buzzing sound was coming from Active Noise Cancelation (ANC) because lots of folks have said the GTs don't have the fake engine noise piped in. Well, as it happens, my ANC value was already set to 0 but the Software ESE was set to 1 -- I was getting fake engine noise, and it was making the subwoofer buzz and hum under acceleration. After setting that value also to 0, no more buzz.

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[Wiley Marmot]

If it were me; I'd also run my/that plan by an audio tech at a reputable car/truck/boat audio shop to get their thoughts as well (as opposed to random dudes on a Mustang Forum you have no idea as to their tech qualifications).

A caveat to that would be if I were going to mimic/duplicate a system or a subsystem a fellow forum member had installed/integrated, and had it successfully up and running in their car.

PS: Not dissing anyone here; you may well be a pro audio tech in the real world and/or be a lay person who knows their audio ****, but it's hard to tell over the internet.

Best of luck, and let us know how it works out (I might want to mimic your pioneering work [if your Mustang hasn't burned to the ground on account of it!])!

 

[Magic88]

If it were me; I'd also run my/that plan by an audio tech at a reputable car/truck/boat audio shop to get their thoughts as well (as opposed to random dudes on a Mustang Forum you have no idea as to their tech qualifications).

A caveat to that would be if I were going to mimic/duplicate a system or a subsystem a fellow forum member had installed/integrated, and had it successfully up and running in their car.

PS: Not dissing anyone here; you may well be a pro audio tech in the real world and/or be a lay person who knows their audio ****, but it's hard to tell over the internet.

Best of luck, and let us know how it works out (I might want to mimic your pioneering work [if your Mustang hasn't burned to the ground on account of it!])!

Past swapping the sub out with something else, I'm taking it to a stereo shop

 

[DCBuckeye]

*snip*

Yeah, sadly I asked the guy who did my tint if he had any audio shops he'd recommend, and his response was essentially "not anywhere near us." I did ask over on r/CarAV, too, and haven't heard anything back yet.

Whether it is this or something modified from this, I'll follow up here and try to post some pics. (Hopefully not of a flaming wreck.)

 

[Zig]

Why use their head when you’ve got your own? I mean, why not stand up your own system and then drop sync output into your head as a feed if needed?

 

[timd38]

I added a factory sub to my F150 and had to have the dealership "install" the link to make it function. You could probably do that part yourself using forscan.

 

[DCBuckeye]

I'll update the original post once this is all done and finished, but for now here's a quick update.

Ground: Finding a good spot to ground the amp and LOC was a pain. I wound up taking out the backseat, loosened a bolt for the passenger-side rear seat belt, sanded down the paint, and did it there, but hunting down a good spot took a solid hour. I was a bit constrained by the length of amp ground wire that I have. I'm going to be mounting the amp to the back of the rear passenger seat, so needed something that could reach it when the seat was up and folded down without pinching or pulling on the wire.

Tapping the Rear Deck Speakers: First, the wiring diagram for the S550 does not work for the S650. The color-coding on the wires is completely different. I didn't discover that until I was on my back, in the trunk, and had peeled back the tesa tape to look at the wiring. Fortunately, this guy over on YouTube seems to have found the correct wiring. Next up I'll get those tapped with posi-taps, then wire and secure the LOC.

 

[DCBuckeye]

I still need to update the graphic in the original post, but this is all done. Wire taps work well, with a small hitch.

Final order of install was:
1. Determine roughly where everything would go. I decided to mount the amp to the back of the seat as it wouldn't fit on the sides of the trunk and I didn't feel like fabricating somethibg from scratch. I also did not want to mount it to the subwoofer box as I want to be able to remove the subwoofer without having to disconnect power and ground cables from the amp.
2. Tap the rear speaker wires. This was my first frustration when I discovered the S550 wiring diagrams don't work for the S650. But, I found a YouTuber who had sorted it out, ran the Posi-tap connectors, and secured the LOC.

3. Find a ground spot for the amp and LOC. After poking around for a while, I took out the bottom of the backseat, and found a bolt for the seatbelt. Sanded the paint off the metal, and secured the ground for the amp and LOC.
4. Ran the power cable through the firewall. I removed the front passenger tire, opened up the rear of the wheel well, then used a utility knife to carefully open up a slot in the gasket. I then fed a wire hanger through. Going back to the interior, I found the wire hanger, taped the power cable to it, pulled it through, then installed the fuse and connected it to the positive harness. (Picture is from when power is reconnected at the very end; should not look like this when you're just attaching thr wire to the harness.)

5. Connect all the wires to the amp.
6. Reconnect the positive and negative terminals of the battery.
7. Turn on the car, turn the radio on low, ensure everything is working, then turn the car off.
8. Screwed the amp into the back of the seat and secure the subwoofer with velcro.

9. Start the car back up and tune the amp.

Note: The power line from the LOC will switch the amp on and off, but it will power up everytime you walk near the car with your key fob. This includes a couple of woofs from the subwoofer. I may reroute the power switch to a fuse, but haven't yet figured out which fuse(s) only come on when the car is turned on.

I think the amp is not that great and will likely swap it out in a few months, but for now it's fine.

 

[Billycar11]

put some Rubber Edge Trim on where those wires go through in first pic so it dont chew through eventually and short out

 

[DCBuckeye]

put some Rubber Edge Trim on where those wires go through in first pic so it dont chew through eventually and short out

Thanks. Haven't finished cleaning up and securing everything, but I'll do that.

 

[24BlueStang]

Looks good. Think the spot you went through the firewall is big enough for 0awg wire to go through?

 

[DCBuckeye]

I updated the original post with the final diagram and workflow. So far, pretty happy, though I'll likely be switching the amp in a couple months.

Looks good. Think the spot you went through the firewall is big enough for 0awg wire to go through?

Honestly, I wouldn't think so, but I read someone say they had managed it (though it wasn't easy).

 

[DCBuckeye]

Well, here is my last update on this thread unless anyone has questions.

I swapped out the cruddy Autotek amplifier and replaced it with an Alpine. Huge improvement on sound and power going to the subwoofer, but I also finally noticed the buzz some folks have been complaining about from the subwoofer when the audio signal is being tapped from the rear deck speakers. I was convinced it was Active Noise Cancellation (ANC), but when I loaded up Forscan and took a look at the codes, I discovered ANC was already completely disabled but the Software Engine Sound Enhancement (ESE) was active.

After I turned that off as well... poof, no more buzzing/humming from the subwoofer. Happy cruising.

 

[Wiley Marmot]

Well now that you've got lots of free time on your hands can you come over and do mine?

 

[24BlueStang]

Well, here is my last update on this thread unless anyone has questions.

I swapped out the cruddy Autotek amplifier and replaced it with an Alpine. Huge improvement on sound and power going to the subwoofer, but I also finally noticed the buzz some folks have been complaining about from the subwoofer when the audio signal is being tapped from the rear deck speakers. I was convinced it was Active Noise Cancellation (ANC), but when I loaded up Forscan and took a look at the codes, I discovered ANC was already completely disabled but the Software Engine Sound Enhancement (ESE) was active.

After I turned that off as well... poof, no more buzzing/humming from the subwoofer. Happy cruising.

What all is needed to get and use forscan. Idk anything about it as this is my first newer ford. Only two other fords I ever owned were a 95 F150 and an 05 Taurus.

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