Need advice on subwoofer install

Var Nazari · July 27, 2020

I have a 2020 Silverado LT with the 8" screen, without Bose.

I'm sort of confused on what all is needed to install a subwoofer and I need some advice on what to buy as well. I want to use the subwoofer as a supplement to my terrible factory speakers. I had good luck doing this with a previous vehicle. I took the bass burden off the door speakers and I had the sub handle all the bass frequencies.

So far I'm looking at this enclosure with the included amp. 200 watts is plenty of amp for my needs.
http://subthump.com/Chevrolet-GMC-Custom-Subwoofer-Boxes/Silverado-And-Sierra-Crew-Cab-Custom-Subwoofer-Enclosures-by-Subthump/2019Up-Crew-Cab/New-2019-New-Body-GM-Crew-Cab-Dual-1012-Downfire-With-Amp-Space-clone.html

And then I'm looking at this harness, but I don't know what add-ons to select. I want the minimum configuration to get around the bass roll-off from the factory.
https://lljcustoms.com/store/ols/products/2014-2018-gm-t-harness-for-8-screens-without-bose-1418gm8

I'm also wondering if the bass knob that's included with the subthump kit will be compatible with the LLJ customs harness, or if I have to buy a separate bass knob that's made for that harness.

And finally, the question of which subwoofer to choose. Like I said earlier, I would like to supplement my factory speakers with this sub. I think the mounting depth of the box is 7". Should I be looking for something that has a wider frequency range? I would like a very tight and punchy speaker for the kick drum, but something that can fill in the other frequencies as well. I listen to almost every kind of music. EDM, Metal, Classic Rock, Country, and once in a rare while even Hip Hop. This enclosure allows for round or square 10 inch woofers.

Any help is appreciated. Thank you

Edited July 27, 2020 by Var Nazari
typo

greco2003 · July 27, 2020

Get the harness from John people have had problems with llj customs. John’s email is [email protected]

he will answer all your questions and give you several options on harness

Var Nazari · July 28, 2020

21 hours ago, greco2003 said:

Get the harness from John people have had problems with llj customs. John’s email is [email protected]

he will answer all your questions and give you several options on harness

I just emailed him. Thanks

greco2003 · July 28, 2020

Just now, Var Nazari said:

I just emailed him. Thanks

No problem he made my harness for my sub install and I got the lc2i from him. On the sub thread a lot of people where having problems with lljcustoms. That’s where I got John’s email from.

Var Nazari · July 29, 2020

6 hours ago, greco2003 said:

No problem he made my harness for my sub install and I got the lc2i from him. On the sub thread a lot of people where having problems with lljcustoms. That’s where I got John’s email from.

He just emailed me back saying he's closed until mid September. So I guess my choices are limited now

Paul 2020RST · July 29, 2020

Does anyone have the color wires being used to go to the LOC? 2020 RST w/ Bose

Rook126 · July 29, 2020

1 hour ago, Paul 2020RST said:

Does anyone have the color wires being used to go to the LOC? 2020 RST w/ Bose

Which speaker signal are you trying to hook up to the LOC, Bose subwoofer or door speakers?

Paul 2020RST · July 29, 2020

49 minutes ago, Rook126 said:

Which speaker signal are you trying to hook up to the LOC, Bose subwoofer or door speakers?

I’m guessing the sub, even though the doors seem to play more bass.

Rook126 · July 29, 2020

16 minutes ago, Paul 2020RST said:

I’m guessing the sub, even though the doors seem to play more bass.

I have a 2020 w/ Bose and was able to locate and access the sub speaker wire beneath the center console without removing the console or any seats. I haven’t seen anyone post on this method yet so here it is.
Remove the plastic side panel from the center console on the passenger side. Think it was held on by several panel clips.
Slide the passenger seat all the way back to expose a carpet seam at the bottom of the console. Pull the carpet flap and peer under the console towards the rear of the vehicle with a flashlight. You should see a thin harness wrapped in black tape anchored to the floor with zip ties. There are only two wires in the tape.
You should be able to get a hand or panel tool in there to wiggle the anchors loose from a threaded stud or bolt.
There wasn’t much slack in the harness but try to pull as much out as you can. Carefully snip the black fabric tape exposing a green and a blue wire. I can’t remember which wire was positive or negative. You will probably have to research wiring diagrams or someone may recall.
I scored and slid the wire insulation to the side exposing the copper wire and then soldered speaker wire to it. Sealed it and taped it back up and put it all back together.
Ran the speaker wire under the passenger seat rails inside a seam in the carpet to the passenger door sill. Then ran it inside the factory wiring track along the passenger side under the door sills to the rear seat where my LOC is located.
This may be difficult to follow so here are a couple images. I hope this helps out the installers out there.

Jeff Cooley · July 29, 2020

That looks great but how did you disconnect the ANC and where did you get your power wire and remote wire for your amp from?

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Rook126 · July 29, 2020

I did not have to bypass the ANC for my minimal setup with just a small single 10” sub supplementing the existing oem sub. I don’t believe ANC is canceling any of my audio output and likely determines my sub’s output as music instead of noise.

I did not need a remote turn on signal for my amp because it already has built-in auto power on sensing the audio signal coming from the Bose sub speaker I tapped into.

Jeff Cooley · July 29, 2020

I did not have to bypass the ANC for my minimal setup with just a small single 10” sub supplementing the existing oem sub. I don’t believe ANC is canceling any of my audio output and likely determines my sub’s output as music instead of noise.

I did not need a remote turn on signal for my amp because it already has built-in auto power on sensing the audio signal coming from the Bose sub speaker I tapped into.

Ok great, thanks. I just want a small sub as well. Maybe I'll be fine without cutting the anc. Worth a shot. Thanks.

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Rook126 · July 29, 2020

I don’t know enough about how the ANC works with GM but I suspect that it sends an audio signal out of the speakers including the sub to cancel out road noise. So far while driving around, I haven’t heard the sub doing anything weird or muting itself out. I’m certain you will be fine with a small setup not meant to blare out the cars next to you in traffic.

Edited July 29, 2020 by Rook126

Jeff Cooley · July 29, 2020

I don’t know enough about how the ANC works with GM but I suspect that it sends an audio signal out of the speakers including the sub to cancel out road noise. So far while driving around, I haven’t heard the sub doing anything weird or muting itself out. I’m certain you will be fine with a small setup not meant to blare out the cars next to you in traffic.

So I found those 2 wires and tapped into them. Both putting out approclx 6.1v. I have a PAC LOC hooked up so only 1 speaker is supposed to get a signal. However I hook everything up and nothing comes out. MY PAC is dual channel but I imagine if I hook 1 side up I should get a signal. I only have the 1 sub on the amp. Thoughts?

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Rook126 · July 29, 2020

Some thoughts.

Check the PAC LOC wiring. I had an older 2ch LOC a while back that required a different combination of input wires to be used if running in mono. Some LOCs require a dedicated ground connection.

Are you using a stereo or mono amp? If stereo, check to make sure you are on the same channel (left input/left output) etc.

Double check any other settings on your amp, switches and gains.

If you have a dual voice coil sub, be sure you are connected to terminals on the same VC.