DiyMobileAudio.com Car Stereo Forum banner
1 - 20 of 308 Posts

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #1 · (Edited)
Going to be a long read but hopefully enjoyable to follow along with my rapid descension into the rabbit hole of car audio.

Finally had made arrangements to find a new 2021 6.2L AT4 in Satin Steel Metallic that had a confirmed delivery date to our local GMC dealer. This is a company truck for our family construction business. As most people know, inventory is literally nill nowadays and getting any sort of options on your vehicles (esp. GM trucks) cause major issues with delivery times. We found this truck with production spot but was coming with no options added but the basic AT4 trim is still decent enough. Love the truck and have had 3 of the previous Sierra body types. The 10 speed is fantastic and finally the interior are getting refreshed.

Before I jump into the audio side of this post, I wanted to briefly show what other mods have been done to the truck:

Exterior:
  • 20x9 Fuel Vector Wheels
  • 275/60/R20 Michelin LTX Defender Tires (Drive 99% on road and the stock Duratracs are noisy af/also have Nokian winter tires)
  • Magnum Headache Rack
  • OEM Off Road Running Boards
  • Illuminated Black Front GMC Emblem
  • Black Rear GMC Emblem
  • Black CarbonPro AT4 Emblems
  • Black OEM Exhaust Tips
  • Truxedo Lo Pro Tonneau Cover
  • Bed Mat
Interior:
  • ProClip Phone Mount
  • OEM All Weather Mats
Mechanical:
  • S&B Cold Air Intake
  • Pulsar LT Programmer
  • J&L Oil Separator
Tire Wheel Car Vehicle Automotive tire

Tire Wheel Car Land vehicle Vehicle


On to the audio side of my journey:

I knew I was going to make some level of audio upgrades because the truck was not coming with Bose system and regardless, the Bose system is a sad system in itself. So I began to research. Hadn't upgraded car audio in anything except high school, had an Infiniti QX4 with Alpine HU, Kicker 700.5, Some Kicker Speakers and CompVR10 Sub. So I started by setting a budget - initially wasn't planning on a sub, just speakers and an amp only and put $1500 as my goal. Long term, boy was I naive on my wants vs price of components.

I went Crutchfield and started a convo with an agent an was able to put together a system that seemed to check all my boxes. I was very, very green at this point and wasn't doing a ton of my own research or talking to many experienced installers. We had spec'ed a system with an amp but I needed to sort out a way to get my HU signal back to my amp. I eventually found LLJ Customs out of Arizona who specializes in custom wiring harnesses. They make a full plug and play wiring harness that intercept the 4 high level speaker outputs under the glove box and provides a long harness to mount your amps anywhere in your vehicle. I got the Loopback option which also includes an additional set of speaker wires that use the OEM speaker wiring without splicing, it is a massive time saver. I also had them added an extra set of speaker wires for my tweeters as I was going to keep my crossovers out back with my amp. Overall a great investment for someone who wants plug and play DIY, just take 5-6 weeks to get.

NavTV still isn't offering their module still, so this was my choice. I run digital now for music but still will use this as my analog source for chimes/nav/factory BT.

Build #1 - Speakers and Deadening Only (waiting for my LLJ harness)
  • Infinity Reference-9630x 6x9 - Components, Front
    • Installed the woofer only during this phase
  • Infinity Kappa 62ix - Coaxial, Rear
  • Dynaliner CCF on outer shells of doors
    • It took me months recognize this is useless without CLD
  • Dynalliner CCF on inner side of plastic door panel
    • Again probably helping with rattles but not resonance
  • Dynamat Xtreme at Speakers
    • Added some butyl rope to seal mounts and SoundSkins Rings

Hood Automotive tire Motor vehicle Car Automotive design
Automotive tire Circuit component Hood Automotive design Office equipment


"Deadening"

Automotive tire Motor vehicle Automotive design Auto part Automotive wheel system
Automotive tire Automotive lighting Automotive design Cameras & optics Motor vehicle


Infiniti Speakers.

Conclusions - To be honest, made a kick ass value oriented build. Had I actually used some CLD on outer and inner door shells, this would probably satisfy the average user. They are sensitive speakers and play most anything you throw at them. For running off just the HU, it was much better than expected.
 

Attachments

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #2 · (Edited)
Build #2 - Add Powered Sub, Speaker Amp, Amp Rack, Wiring Harness
  • AudioControl LC4.800
  • JL Audio Powered Microsub 8"
  • LLJ Customs Wiring Harness
  • Amp Rack
  • Tweeters from Infiniti 6x9 set
In between the time I got the speakers installed and the time from receiving my harness I had done enough research to convince myself that I wanted to add a sub to my system. I set on finding the most simple solution and ended up settling with the 8" JL Powered Microsub. I was going to build a small amp rack to house my distribution blocks and mount my amps and crossovers.

I had bought the LC4.800 already from build one. Not a bad amp at all.

Got my harness:
Tableware Electric blue Jewellery Wire Circle


So I began my amp rack design and fab (my carpet job was TERRIBLE):

Electronic instrument Grey Font Audio equipment Gas
Saw Wood Machine tool Engineering Gas


Mocked up with foam and then rack built from MDF and marine carpet.

Tableware Dishware Personal luxury car Tints and shades Serveware
Hood Luggage and bags Bag Sunglasses Automotive design


Mocked up in cab with equipment.

Blue Sleeve Bag Denim Material property
Shoe Photograph Light Table Black


Wired up as much as possible before install

Audio equipment Automotive tire Auto part Trunk Machine
Automotive tire Audio equipment Gas Auto part Metal


Installed!

Not the best job looking back but was happy with my first DIY set up in almost 15 years. This system sounded really solid, again, for its value. But the deeper I began to read, I realized that the home audio audiophile in me knew there was much more potential out there. And this is what began my revolving door of changes and some dumb decisions, I have learned from them but man, I should have slowed my roll during the next couple of builds.
 

Attachments

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #3 · (Edited)
Build #2A - 10" Powered Sub and Bass Knob
  • JL Audio ACP110LG-TW1 Powered Sub
  • JL Bass Knob
The 8" just wasn't reaching the lows and output I was looking for and ended up exchanging the 8", 250W RMS with 10", 400W RMS version and it was well worth it. The 10" ported after break in does incredible for it's size. Also added the JL bass knob out front.

Product Camera lens Audio equipment Cameras & optics Gas


8" vs 10"

Automotive tire Vehicle Automotive design Motor vehicle Fixture


Bass Knob - clean and easy
 

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #4 · (Edited)
Build #3 - New Speakers, Amps, Subs...well mostly everything.
  • Audiofrog G60S - Components, Passive Front
  • Audiofrog GS62 - Coaxial, Rear
  • JL Stealthbox w/ 2 12TW3-D8 Subs @ 2 ohms
  • JL XD 1000/5
  • Audiocontrol LCQ-1 LOC/EQ
  • Deadening and LLJ Harness from previous builds
I was in my return window w/ Curtchfield (this formed a bad habit) and decided to take the plunge into what I felt was the "next level" for the system. I read a ton of great things on the AF GS set and wanted a sub box that had 2 quality subs and some room to mount the amps/components I wanted. The Stealhbox hit these boxes and fit like a glove. This system, had I gone with a DSP in lieu of the LCQ-1, I think would have probably been enough for me. It sounds damn, damn good. Warm, accurate and deep and I have very basic understandings of crossovers or tuning at this point. I used a IMM-6 and the phone RTA, some O scope work and felt I had it dialed for what I had at my disposal. I was going to just buy a DSP to finish it off but my truck hit a deer and then I decided to move to Build #4 on the next post. But first, the handful of pics I have of Build #3.

Update: Wanted to chime on a more in depth review of this system:

G60S - For the money, these crossed at 80 hz handled anything I could throw at them. They are the pretty much type of sound I was aiming for - just warm enough but very accurate and detailed. 6" are fairly low in the GMC doors and the tweeter is off axis in the dash corner facing the windshield (stock location is a ~2.5" wideband). My only gripe are the external crossovers, if you keep your crossovers back with your amps, you end up with a clump of wiring and 4 small boxes to store as they don't mount with anything besides VHB/Velcro.

GS62 - Not a ton to say, they are popular for a reason. Clear, powerful and easy to install.

JL Stealthbox w/ 2 TW312-D8 - Wired at 2 ohms, I have had them on 600 W from the XD1000 and 750 on the HD750 and they hit harder than I will ever need. To be honest, I never got the crossover and gain dialed in well to scale well with volume but with a DSP and pro tune coming, I am very optimistic to get some more accuracy and depth from this. The enclosure is solid as a rock (as expected with fiberglass) and is shipped beyond well. I think I would have been just as happy with an MTI box as well but liked the price and open shelf area to mount my amps. Avoiding removing the rear seat cause it's a production on the GMCs, and as a company truck, trying to avoid too much custom fab that's not removable.

JL XD1000/5 - Tiny rectangle of power - worked like a champ for me, just outgrew it. Highly recommend.

AudioControl LCQ-1 - Worked well as an LOC, though it was sensitive to input voltage aka if I went one number above my max undistorted HU volume, the unit would shut off and cycle back on. Pretty sure this was more my inexperience with setting gains at this point. Has some EQ built in but it is only 6 bands a channel and does help but barely. I tried thinking this would replace the reason I wanted a DSP but it wasn't the answer long term.

Overall, this system was extremely enjoyable once it broke in a bit. With a Helix DSP Mini, I think this a sweet truck system that's very simple to install and tune.

Furniture Table Publication Shelving Shelf


New components

Bumper Gas Rectangle Telephony Tints and shades
Helmet Leg Automotive tire Light Glove


Car Vehicle Motor vehicle Automotive lighting Hood
Hood Textile Automotive tire Motor vehicle Automotive exterior


Stealthbox and amps in from passenger side

Hood Automotive tire Automotive design Wood Automotive lighting
Motor vehicle Vehicle Automotive design Car Trunk


Driver's Side

Office equipment Gas Rectangle Electronic instrument Auto part
Office supplies Office equipment Rectangle Font Machine


XD1000/5 and LCQ-1
 

Attachments

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #5 · (Edited)
Build #4 - AF GB Active, Helix V8 + P One + Conductor, Resonix, Digital Signal
  • Audiofrog GB 60/15 Active - Front Stage
  • Retain GS62 - Rear
  • Helix V8 DSP Amp
  • Helix P One Sub Amp
  • Conductor w/ Custom Mount from @DeLander
  • Resonix CLD + Leftover CCF - Exterior Door Shell
  • Soundskins Pro SSK Kit - Interior Door Shell
  • AppleCCK/Topping D10S/Audioquest for Digital Input
  • ABS Speaker mounts from @DeLander
This is really going to be my build for the remainder of the year. I started working with @SkizeR about halfway through these purchases and feel confident in this being a superb 2 way active set up with a great foundation for a future 3 way set up later this year or next year. Probably trying BLAM's S200.300 to get some 2 ohm power from the V8.

I have done some work planning my black ABS amp rack and can share some work I have been doing @DeLander . I should be getting this all installed this upcoming weekend and will autoEQ for now and have Nick tune it remotely once we get some free time.

Rectangle Slope Font Parallel Diagram


Amp rack that will live in my Stealthbox mounting pocket

Vehicle Blue Hood Automotive tire Automotive design


Mocked up conductor mount location

Font Rectangle Parallel Slope Electric blue


The CAD plan I shared with Todd aka Delander

Fluid Rectangle Gas Circle Composite material
Automotive design Rectangle Art Material property Wood


First renderings

Rectangle Textile Font Cake decorating supply Art


Cut 2 sets in case I mess one up

Blue Automotive tire Finger Automotive exterior Bumper
Blue Wood Flooring Font Automotive design
Wood Flooring Floor Gas Couch


Shaped and ready to ship. I will be painting these with SEM black once I get them glued and sanded to fit.


Font Gas Wood Cuisine Flooring


And lastly the speaker mounts for the GB60s, GB15s and GS 62s

I will be updating as I get this next step installed! Cannot wait!
 

·
Super Moderator
Joined
·
2,211 Posts
Not sure about the "Future", but what you have done looks great!

Any word on how it sounds?
 

·
Registered
2016 GMC Sierra
Joined
·
541 Posts
clean truck, I'm digging the wheels. and like you some of us have learned the same way, buying stuff before figuring out what we really want to accomplish. part of the diy mindset I guess. can't wait to see your next iteration.
 

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #8 ·
Thanks to both of you. Will get some more detail posted here soon. And also share where we are heading with future 3 way configuration.
 

·
Registered
2017 GMC Sierra 1500 Denali
Joined
·
1,876 Posts
Great write up, hopefully this will help some people in the future as these trucks start to become more available. Couldn’t help but laugh at the revolving door (which is all of us) and the bad habit comment towards crutchfield. Seems like you’ve finally found the correct path, happy to hear you got your truck back to and it looks great!!

Looks like DeLander knocked it out of the park once again.
 

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #10 ·
Great write up, hopefully this will help some people in the future as these trucks start to become more available. Couldn’t help but laugh at the revolving door (which is all of us) and the bad habit comment towards crutchfield. Seems like you’ve finally found the correct path, happy to hear you got your truck back to and it looks great!!

Looks like DeLander knocked it out of the park once again.
Hahaha yup. Definitely have learned to slow my roll when in to comes making major purchases. At least this time around I feel I’m well set up for a 3 way without having to make major equipment changes. Thanks again for you early help too.

Still waiting for the truck from the body shop sadly, should be be middle of this week.

Todd has been awesome, anxious to see his work once it ships here early next week.
 

·
Registered
2017 GMC Sierra 1500 Denali
Joined
·
1,876 Posts
Hahaha yup. Definitely have learned to slow my roll when in to comes making major purchases. At least this time around I feel I’m well set up for a 3 way without having to make major equipment changes. Thanks again for you early help too.

Still waiting for the truck from the body shop sadly, should be be middle of this week.

Todd has been awesome, anxious to see his work once it ships here early next week.
Mines out of commission at the moment to, Thanks to the lifter issue also got a new tcm so hopefully that does something for that pos 8 sp.🤞

Bought a range earlier to disable the afm. Amazon delivered it in under 2 hrs which is pretty incredible, wish i had a truck to put it in!!

Keep us posted, Can’t wait to hear your thoughts about revision 4.0
 

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #13 ·
Mines out of commission at the moment to, Thanks to the lifter issue also got a new tcm so hopefully that does something for that pos 8 sp.🤞

Bought a range earlier to disable the afm. Amazon delivered it in under 2 hrs which is pretty incredible, wish i had a truck to put it in!!

Keep us posted, Can’t wait to hear your thoughts about revision 4.0
That's right, forgot you had your lifters go, I'm crossing my fingers I don't deal with them. The AFM delete helps more than expected and I had my 8 speed re-flashed like three times to help it out.

Still waiting on a few pieces to the build aka the mounts and amps but everything ships towards me Monday. Very very excited to get it all back up and running. Been using my dad's lifted 2018 wrangler and want to shoot myself from the handling and noise pollution it has lol
 

·
Registered
2016 Gmc Sierra SLT
Joined
·
143 Posts
A bit off topic but have you guys with the 8 speed had the fluid updated per the bulletin that came out a while back? I found it helped more than expected. Also, try turning OFF grade braking and turn ON trailer mode, it changes the shift points on definitely tamed the shifting significantly.
 
  • Like
Reactions: clange2485

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #15 ·
A bit off topic but have you guys with the 8 speed had the fluid updated per the bulletin that came out a while back? I found it helped more than expected. Also, try turning OFF grade breaking and turn ON trailer mode, it changes the shift points on definitely tamed the shifting significantly.
Tow mode certainly helped and had the new fluid but never tried grade braking off. On to the 10 speed now but I would be curious to try the grade braking.
 

·
Registered
2017 GMC Sierra 1500 Denali
Joined
·
1,876 Posts
A bit off topic but have you guys with the 8 speed had the fluid updated per the bulletin that came out a while back? I found it helped more than expected. Also, try turning OFF grade braking and turn ON trailer mode, it changes the shift points on definitely tamed the shifting significantly.
i got the fluid changed about 2 1/2 yrs ago and it really helped but after 30k miles or so it’s starting to get a little clunky again. Thanks for the tip, hopefully i don’t need it but it’s something to try.
 

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #18 ·
Dropped by my body shop a few minutes ago and got confirmed I’ll have my truck Friday for the deer hit. Hit a deer running out of the median on I-95 six weeks ago.
Automotive parking light Automotive side marker light Tire Wheel Vehicle

Wheel Tire Vehicle Car Motor vehicle

Tire Wheel Automotive tail & brake light Grille Car

Wheel Tire Car Automotive parking light Land vehicle


Heading into paint in about an hour.
Wheel Tire Car Vehicle Motor vehicle
 

·
Registered
2016 Gmc Sierra SLT
Joined
·
143 Posts
Glad to hear your truck will be fixed soon! I live in the country and see this frequently. It's always amazing how much damage they can do. Hope it's as good as new when you get it back!
 

·
Premium Member
2021 GMC Sierra AT4
Joined
·
448 Posts
Discussion Starter · #20 ·
Glad to hear your truck will be fixed soon! I live in the country and see this frequently. It's always amazing how much damage they can do. Hope it's as good as new when you get it back!
Yeah it blew me away, roughly 19k in damage when said and done. Seems like the antler got hooked in my headlight and then it tumbled down the side of my truck while I was doing about 70 mph :(.

C'est la vie but she's all painted now.
 
1 - 20 of 308 Posts
Top