2015 Tahoe LTZ aftermarket amp and sub install

Discussion in 'Audio & Electronics' started by NathanSMSU, Mar 29, 2016.

  1. NathanSMSU

    NathanSMSU TYF Newbie

    Posts:
    10
    Likes Received:
    0
    Joined:
    Mar 26, 2016
    Name:
    Nathan
    The install is complete! It took about 4.5 hours yesterday afternoon/evening. A few key takeaways to add to what I mentioned above.

    1. My original amp kit (Scosche Amp Wiring Kit) came with 16.5ft of power cable....this isn't going to be enough! You need a minimum of 20ft. I discovered this after doing some pre-measuring a few days before the install. I couldn't find locally another 6 feet of 8awg oxygen free wire so I just picked up another complete amp kit off of Amazon for $14! I ended up using a combination of both the first and second amp kit, even though the second would have been sufficient for the complete install. Here is the link to the 2nd amp kit: Boss Audio KIT2 8 Gauge Amplifier Installation Kit

    I will start with the finished product first....and then back my way into how it all came together. I won't have time to complete the thread right now, but stay tuned! For now here are a few shots!
     
  2. rattmobbins

    rattmobbins Full Access Member

    Posts:
    146
    Likes Received:
    45
    Joined:
    Mar 23, 2016
    Name:
    Matt
    Pretty nice. How's it sound running with the factory system?

    Really want to add some bass to my stock Escalade system but think I might wait for JL to make a stealthbox for the '15+.
     
  3. NathanSMSU

    NathanSMSU TYF Newbie

    Posts:
    10
    Likes Received:
    0
    Joined:
    Mar 26, 2016
    Name:
    Nathan
    I'm pretty impressed with a single 12. Of course I only have it turned up 1/2 way to let the sub break in for a week or so. It moved enough air to pull the neighbors out from across the street last night to see "what the hell was going on"! We don't haul a ton of stuff, but when needed a few wires to disconnect and I can just put the box aside...
     
  4. NathanSMSU

    NathanSMSU TYF Newbie

    Posts:
    10
    Likes Received:
    0
    Joined:
    Mar 26, 2016
    Name:
    Nathan
    Alright...let me try to document out the steps it took to complete the install. I have some pictures to include along the way. You can do this...it's not too hard. Set aside 4-6 hours. Get all of our equipment ready. See my setup below

    Step 1. I"m going to assume you have all the needed hardware, and tools. Make sure you have a 10mm socket handy as it's used in multiple places. Watch the video of the guy doing the install on the Sierra that I posted at the start of this. 3/4 of this video aligns exactly to the 2015 Tahoe...step for step!

    Step 2. Pop off battery top cover, located on passenger side under hood. You'll see multiple battery posts, even one that is exposed without a wire running to it. I didn't have a bolt handy to fit it so I connected to the first post, nearest the front. If you purchase the second kit (Boss Audio) you'll need to cut the power cable (about 2.5 - 3 feet from the battery) and install the fuse and the attach the remaining 17ft of power cable. Don't forget to run the wire loom over the wire! It's easier to do so before you have the fuse in-line. See pictures below.

    Zip tie that guy to the wire/loom that's already running along the backside of the engine compartment on over to the far driver side.

    Step 3. Cut the little nipple off the rubber boot that you'll see in the picture below. You can use a long screw driver to poke down in the hole to make sure you have a clear path heading down towards the bottom of the inside of the cabin. The picture below is obviously the finished deal....but you'll need to skip to Step 4 to dismantle the inside in order to see/feel the power cable when you start to feed it through the hole you cut in the rubber boot.

    Step 4. Probably the most challenging part of the install....As mentioned previously watch the Sierra install video. The guy does a nice job of showing how to pop the top off the black box near the brake pedal. You goal is to use the 10mm socket to remove this electrical housing, move it aside, and reach up back behind there looking for a round rubber grommet, about 4 inches in 5 inches in diameter . You need to yank that gasket out....it's pretty much worthless as you won't be re-installing it. It will be handy to have a buddy at this point start feeding the power wire through the rubber boot (mentioned in step 3) and you can be feeling for it from the insdie. Pull the power wire through once you can get your hands on it!

    Step 5. Now it's time to install your amp turn on wire. You'll be connecting this to a empty pin inside that electrical box you just unbolted. The picture below shows the 3rd pin from the top on the left hand side. In my photo it's slightly bent to the right. This is a fairly small pin, so you may need to pick up a wire-end to connect to it.
    Step 6. Now it's time to start running your power, and amp turn on wire to the rear of the vehicle. You'll pop up the lower running cover from the driver down through the passenger. See the pics below!
    There is a nice little groove the cables will fit into. Don't put the covers back yet if the amp you've purchased has an adjustable base knob as you'll need to run this back up front after you have the amp installed in the rear!

    Step 7. Here is where you can get a little creative. We choose to mount the amp to the side of the box as you saw a few posts above. Ideally you wan't it somewhere to get SOME airflow as the amp will heat up! I would first remove the storage compartment in the very back. Open it up, there is a removable liner in the bottom of it, and on both sides is a big circle nut looking thing you can hand unscrew. This will now lift out...put it aside. This way you can get to the bottom of the drive side rear panel to run your wires easier. You now need to pull signal off of the factory amp. The factory amp is accessable through the rear fuse panel on the inside back driver side Pop that panel off and then unscrew the tire jack and remove it. Makes it easier to work around...you'll put it back later. Behind that you'll see the factory amp. if I remember correctly the top connector into the amp has the cables you need. Mentioned previously in the post are the colors for the + and - Subwoofer wires. You can see in the picture below they are pulled out behind the screw driver. You may need to trim back some of the factory black wire tape/loom they have.

    You'll need to use a wire tap connectors to splice you speaker wires into the factor amp out wires mentioned above. These speaker wires will then wire into your line-converter. Since we don't have left/right outputs you'll notice in the picture below they are twisted together. Make sure you get the polarity right (positive to positive..etc)
    Your RCA cables will plug into the line-converter and then into the amp. I won't post details about the amp as you may have a different one...follow the manufacturer instructions for the amp! I chose to run the wires down underneath the the back panel. In the picture above you can see the power wire, bass knob wire, and the amp turn on wire. I had NOT ran the amp ground wire yet. I mention it later on. I have yet to hook up the RCA cables, but they ran the same path. You can plug the factory connector back into the amp, double sided tap the line-converter somewhere inside there, put the tire jack back. My line converter had an adjustable knob of which I just have it cranked as I want to adjust the base from the amp. You'll also need to ground the amp. I grounded it to the bottom screw of the factory amp that you can see just below where the car jack screwed in.

    Step 8. Now it's time to wire up the sub. My sub has dual 4ohm connectors. I wired these in parallel (positive to positive, negative to negative) to run it down to 2ohms. You'll then run a wire from the positive to the inside of the box, and same with the negative. See picture below
    Screw the sub into the box!

    Step 9. It's time to mount the amp. I mounted mine to the side of the box. You'll see the RCA wires from the line-connector, the power wire, ground wire, the amp turn on wire, the ground, and then the base adjust wire. You'll need to follow that same path of wires (power/amp turn on) that you ran from the front and run the base adjuster knob wire up to the front. I mounted mine on the inside of the drivers seat so I could reach it easily. See picture of amp and wires below

    Step 10. Turn on accessory power. In my LTZ with the push button start you just need to push the button once, not hold it down like you would to start it. You should get power to the amp and the sub should start working! Follow the manufacturer advice on tuning the amp. I'm keeping mine tuned fairly calm for a bit to allow for break-in time of the sub! You are done! Boom Boom!
     
    Last edited: Apr 9, 2016
  5. NathanSMSU

    NathanSMSU TYF Newbie

    Posts:
    10
    Likes Received:
    0
    Joined:
    Mar 26, 2016
    Name:
    Nathan
    It's been a few days now and everything is still going good, but I am hearing some "vibration" sounds coming from the front two dash speakers. It's not that the are vibrating, but I believe the BOSE noise cancelling system is acting up. I need to identify either how to turn it off, or snip the wire to the MIC that does the listening.

    Has anyone else experienced this?
     
  6. rattmobbins

    rattmobbins Full Access Member

    Posts:
    146
    Likes Received:
    45
    Joined:
    Mar 23, 2016
    Name:
    Matt
    Bum deal about having to disable the noise canceling system, but I'd heard previously that was a requirement when adding aftermarket stereo gear. :(
     
  7. NathanSMSU

    NathanSMSU TYF Newbie

    Posts:
    10
    Likes Received:
    0
    Joined:
    Mar 26, 2016
    Name:
    Nathan
    Yea....and it's a really weird "vibration"....I hear it coming from passenger side, and my wife in the passenger seat hears it coming from driver side. I've swapped back and forth and can confirm neither of us are going crazy!

    I've tried moving around the focal point....doesn't help. One theory I'm still trying to prove out is rolling down the windows some....I think this may disable the noise cancelling system. Makes since? If you are getting "wind noise" from the windows down you don't want the speakers trying to compensate/cancel it out.

    More to come..
     
  8. john kim

    john kim TYF Newbie

    Posts:
    1
    Likes Received:
    0
    Joined:
    Jul 31, 2017
    Name:
    john kim
    Hi, I'm trying to add a sub as well. Whatever happened to the vibration/noise canceling noise you spoke of?
    Thanks,
    John
     
  9. Bighurk

    Bighurk TYF Newbie

    Posts:
    25
    Likes Received:
    1
    Joined:
    Jun 1, 2015
    Name:
    hercules
    Yes i am curious to find out as well what happened
     

Share This Page