Stereo Mods - Adding an amp and harness

[MesaRat]

Does anyone know if there are aftermarket general harnesses or loop harnesses that plug between the back of the infotainment system and the body harness?  I want to be able to take the audio signal from each of the speakers, send it to the rear of the truck into a DSP and amp, and then back to the body harness and into the speakers.  I don't want to cut factory wiring.  I've checked Crutchfield and a little bit online but i don't seem to see anything for 2020.

 

New to GM trucks and dealer is currently locating my truck for a dealer swap, and appreciate any help or input.

 

Thanks

MR

[davester]

phone/contact crutchfield.com, they should know about a harness for inserting an amp into your audio system.

[Reaper5699]

https://lljcustoms.com/

 

He makes a harness that plugs in....has several options for it.  I was going to order one, but settled on replacing the front 4 speakers and adding an amp/mtx solobaric.

[MesaRat]

Thanks reaper.  it looks like they have what i am looking for.  by any chance have you (or anyone else) done stereo mods?  i have no familiarity with GM but numerous upgrades to fords.

[Reaper5699]

I replaced the front dash and door speakers with a Kenwood set KFC-XP6903C.  They sound great and I don't really think it needs an amp for my use....gets loud enough without distortion.  The dash speakers were a direct bolt in (I clipped the plug off the stock speakers and re-wired into the Kenwood leads) and the 6x9 was bolt in after you snip the bracket down to fit the Chevy.  I had a 10" solobaric in a box that I transferred from my 4 runner that fits perfectly under the rear seat.  Running that with a 200W per channel amp...again, more than enough for me.  I used an LC2i to convert the rear door speaker signal to RCA and add the bass frequencies back.  The LC2i lets you bring back the bass that the stock system cuts out...quite a few you tube videos on it.  Amp and LC2i are under the passenger seat, just took the entire seat out to make it easier.  Wasn't too bad...took a bit of time to make sure it was all right and tidy.  I also used a marine battery switch to use as a disconnect from my battery to my amp and lights.

The set he sells in the link I posted is two plugs with wire that basically intercepts the stock signal to send to an amp, and then sends the amp signal back to the speakers.  I'm not a super audio snob, but I like it to sound good, and just the Kenwood speakers makes a huge difference in the quality of sound.  The bass fills in the low end details.  I'll relate any further details as I did them if you want.

 

Speakers:  https://www.kenwood.com/usa/car/excelon/kfc-xp6903c/ 

 

LC2i:

https://www.crutchfield.com/S-iYnQ89AlBFZ/p_161LC2IB/AudioControl-LC2i-Black.html?XVINQ=GW3&XVVer=67A&awcp=&awcr=396288658483&awdv=c&awkw=lc2i&awmt=e&awnw=g&awug=1013442&gclid=Cj0KCQjw3qzzBRDnARIsAECmryo_TZAiVMyg7oO4CSi8zkQ3WV8g4Z8s0RAw2X201h3TNyzZtB-z3QwaAk32EALw_wcB

 

Sub:  https://www.crutchfield.com/p_206TL7S102/Kicker-44TL7S102.html

[Weaverstreet]

Great post. I'm Considering just the speaker swap for now. Did you listen to the system with just the front speakers swapped? 

I will eventually get a sub, but I know the stock front speakers need more punch. 

[Reaper5699]

Speakers were a night and day difference.  Once you take the stock speakers out, you'll wonder how they even made sound as poorly as they are made.  The magnets on them were so small.  Swapping the rear door speakers may not even need a sub for some, but mine was just sitting there so I threw it in.  The dash speaker is a 2 1/2 inch-ish speaker so mine sounds more like a mid-range with the bass removed, which I like...I've had some tweeters the are just too much high freq you can hear coming from that area.  I'm not really brand specific for loyalty, but the Kenwood speakers were designed for this type of application and they do sound good.  2 1/2 tweeter and 6x9 mid.

The rear door speakers allegedly roll off base when turned up, which I believe to be true as the LC2i has a certain point that the bass comes back in as you turn it up.

 

The Kenwood speakers were $200 at a local stereo shop, much cheaper than Crutchfield, and Amazon is not an authorized reseller so I went local with them. 

[MesaRat]

Thanks so much Reaper.  This is really helpful.

 

I am getting an LT with all the Conv packages.   I also have 2 subs, a Dayton Audio DSP (4 channels in and up to 8 channels out), 5 channel JBL Club amp (sub out and 4 channels), JL Audio 6x9s that i may use some or all in the new truck. 

 

The truck has the upgraded HD Radio 8" system but not Bose. Is this the same config you have on your truck?  I did listen to a Bose and the HD Radio 8" and I didn't hear a big difference and i would tend to agree with you on loudness.  I may do what you did (taking signal from the rears using my DSP).

 

Question on the dash tweeters - are they 3 1/2" or 2 1/2?  I checked them out on Crutchfield and they are listed 3 1/2 but you wrote 2 1/2.

 

Also, how tight is the Kicker fit under the seats?  If I go full bore I will need to figure out how to get everything under the rear seat - unless there is someway to get behind the rear seats, i tried to find a way to release the upper seat backs on the dealer lot but couldn't seem to find a way to do it.

[Reaper5699]

My bad...3 1/2.  I remember seeing something that the seat back wasn't meant to be removed...i.e. very hard to get to everything.  I'll take a pic of the sub under the seat.

[Reaper5699]

In the pic, I haven't removed the jack fixture, so it will scoot back another 3 inches.  You can see the gap on the left...it will sit flush all the way back.

[MesaRat]

appreciate it and you've given me a lot to think about.  are you planning on securing the sub and if so how?

 

doing the math - I will need a $350 loop harness and a good bit of space under rear seats to use my existing 5ch amp.  if i use my DSP, get a small mono or bridged 2ch amp and the solobaric 10" it will cost about $450.  However, if i use my subs, DSP, and just buy a 1 or 2-ch amp it will be around $150.

 

I have two Kenwood KFC-XW1200F eXcelon 12 inch Shallow Subwoofers with sub-par boxes (not enough volume).  I do like some thumps\ in my system and am curious if you are able to "feel" the bass with the kicker? (Not talking about license plate rattling but a good kick inside the truck for heavy bass music).

 

I found on the Silverado 1500 forum the procedures to fold down rear seats, so when I finally get the truck i will try and see how much room is back there.  I assume this carries over to the HD.

 

 

Technical Bulletin - 2019 Chevy Silverado Rear Seat Removal.pdf

Edited March 14, 2020 by MesaRat
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[Reaper5699]

Yes, that solobaric will pound even at low volumes.

I'm going to use a strap of some sort to keep it down and from moving.

 

Good luck!

[jjackkrash]

If anyone knows, is the Crew Cab the same under seats for the HD's as the 1500s?  I am looking at a Stealth Box:

 

https://www.abt.com/product/133728/JL-Audio-Stealthbox-For-2019-Up-Gen-4-Chevrolet-Silverado-GMC-Sierra-Crew-Cab-Trucks-SBGMSLVCC412TW3.html

[FirstAscent]

If anyone knows, is the Crew Cab the same under seats for the HD's as the 1500s?  I am looking at a Stealth Box:
 
https://www.abt.com/product/133728/JL-Audio-Stealthbox-For-2019-Up-Gen-4-Chevrolet-Silverado-GMC-Sierra-Crew-Cab-Trucks-SBGMSLVCC412TW3.html

I believe the whole interior is the same, also the additional larger GM underseat storage is the same part number for HD and 1500’s. I can’t confirm that but someone else did in another thread. So I think you’re safe.

[jjackkrash]

23 hours ago, FirstAscent said:

I believe the whole interior is the same, also the additional larger GM underseat storage is the same part number for HD and 1500’s. I can’t confirm that but someone else did in another thread. So I think you’re safe.

I am probably having an outfit in Portland gut the whole Bose system and throw it in the trash, and I'm sure they can fab up a box, but it sure would be nice if it fit.  I had a stealth box two trucks ago and it really was butter.  You just know it is going to be perfect volume for the drivers if JL makes the box.