2019 GMC Terrain build

[Dafaseles]

So, I took a break from my build in my truck to help a friend out with his build. 

I didn't know him up until maybe 2 months ago or so. His Terrain had car audio stickers all over the back, and around here, people who are big into car audio are free and far between. I saw him sitting in his Terrain in the Home Depot parking lot, so I introduced myself as a fellow basshead. He had a single 15" Skar VXF running off a SKV21500.1D in a crappy, thrown together box. He told me about his plans to get another 15, and another amp, and wall them. 

Turns out, dude lives around the corner from me. Small world! I told him to come through and I'd tune his mono and highs amp with my DD-1 and CC-1. When he did, he mentioned his "builder" hadn't even started the box for the 2 15's yet. I told him "fuck it. We can do it". So we did. 

[Dafaseles]

First things first, come up with a game plan. 

Spoke to Mechman and a couple other companies, but no one made an upgraded alternator for his Terrain that seemed legit enough. It is what it is. So, here's the run down of the equipment we're planning on using....

2 15" Skar VXF subs

2 SKv21500.1D's 

1 XS Power D4800 under the hood

1 XS Power D7500 in the back (unless anyone thinks such a big 2nd battery is a bad idea.)

4 Skar VX35-ST 3.5" bullet tweeters (2 in each front door) 

8 8 ohm Skar FXS65 6.5" midrange  speakers (4 in each door) 

1 SKv2-200.4 for the mids

1 SKv2-100.4 for the tweeters

Audio Control LC2-I for factory had unit integration

And a few other odds and ends (1/0 cable, RCA's, this thing, that thing) 

Then, we got a design

Sealed section is 4 cubic feet

Ported section is 9.3 cubic feet net. 130 square inches of port area, 14 in² per foot, tuned to 47 hz. 

[Dafaseles]

So, we got some ¾" MDF, and started building. 

I've wanted to try other kinds of wood, specifically Baltic birch, but I can't bring myself to actually do it. I've only ever used MDF. Just one of my weird ticks I guess. Anyway......

Let's get started

Measuring and marking the first of many cuts

Setting up the straight edge. All the cuts made for this enclosure where done with my skill saw. I didn't have access to a table saw. So what did I learn from this build? I need a take saw. So what did I do after we built the box? Bought a table saw 🤣. And yes, that is my tailgate. After about 2 cuts on the tailgate, we got some saw horses. Made things a lot easier. 

First piece cut. 

For all the pieces of this enclosure, we doubled up, glued and screwed the pieces together, making a single 1½" piece instead of just a ¾" piece. That was a challenge. 

First piece glued and screwed together. 

[Dafaseles]

So, we kept cutting, gluing and screwing. I had to treat the baffle a little different though. 

So, the cone will be firing into the sealed section, while the motor will sit in the ported section. So, I had to cut the holes in the baffle to be perfect around the surround. There's probably a better, faster way to do this, but this is how I did it. 

First, laid the sub face down on a board. Traced it out, then cut that with my jigsaw. Then I screwed that piece into the sub, being careful not to tighten it too much. I was afraid of damaging the surround. 

Then, using my flush trim bit on my router, I cut this template to the exact size of the outer ring of the sub. I didn't get pictures of the next part, but I measured the distance from the edge of the subwoofer, to the surround. Then, I cut the template smaller using my rabbiting bit, flipping it over, then using my flush trim bit to smooth it out. Then, repeating this again to compensate for my ½" flush trim bit. 

Then I measured it out, found where I wanted to place the subs on the baffle, used template tape to secure the template to the baffle, drilled a hole, and started cutting

A little small router table, baffle cutting action. 

Though time consuming, I was very happy with how it turned out

I didn't get pictures of this either for some reason. 

Next, we glued and screwed to second baffle piece onto this one, I drilled holes for my flush trim bit, and went to cutting out the holes on the second piece. 

so that's how they'll look from inside the sealed section. 

Then I rounded the edges for good measure

[Dafaseles]

Next, I did the brace for the sealed section. 

Very simple, glued and screwed together, drilled some holes for my jigsaw, then cut out the rectangles. 

Then finished it up by sanding it nice and straight

Then, of course, I rounded the edges with the router

Next, we tackled the plexy insert. 

First, I traced the plexiglass piece onto the board, then cut it out with the jigsaw (of course, turns out I didn't get pictures). Used the template tape to secure the plexiglass onto the template, then used the old flush trim bit to make it exact. Then used the rabbiting bit to shave it down ½" to account for the ½" flush trim bit. 

Secured the template into the front piece, drilled my hole, then cut the piece out. 

Next, I had to make the template even smaller for the back piece, so we could attach the plexy to it. It turned out pretty good. 

We then drilled holes for the threaded inserts. Screwed and glued them into place using some E6000 glue, 2" apart, all the way around. Drilled some holes in the plexy (very carefully) and used flat head bolts to secure the plexy on top of some expanding foam weather stripping. 

plexiglass is fucking expensive! Lol

[Dafaseles]

Next, really quick, built the port, rounded the edges

At this point, all the pieces where cut and ready to install. 

We started by building a nice platform for the box to sit nice and flat upon. Didn't get any pictures of it, but we made it out of 2×4's and bolted the platform to the chassis. 

Then we started building. 

We bolted the bottom onto the platform, then when fitting the sides, we found that the "oh shit" handles where in the way. Took them apart and there was a metal bracket in the way

Yeah, we just took a cutting wheel to it, and chopped it out of our way. 

got the side up nice and easy after that

We bought a little jig that drilled starter holes at an angle, to make it easier to assemble inside the vehicle. 

Then, came the back of the enclosure

he then took it home and started painting

He's got a neon/ florescent green theme going on his ride, so that's what he painted it. He also caulked and fiberglass the seams to make sure no air leaks. 

Installed the baffle next

And a nice little under the baffle shot

We left the one side off for ease of installing the subs and whatnot. 

[Dafaseles]

While this is going on, my friend has also been working on his doors. 

The door will house 3 6.5's and 2 bullet tweeters with 1 6.5 in a kick panel pod.

Just a lightweight layout to begin the process

He had to cut a little off the door panel under the fleece. This is the door panel taking shape

A little in car fitment. You can see where everything is going to go. 

He covered the door panel in the same vinyl that comes inside the vehicle for that matchy-matchy look. 

and this is the final product. Maybe not as clean as I would have wanted it, but he likes it, and really, that's all that matters. He's happy, I'm happy for him and happy to help. He wants to rework the vinyl eventually though, and try to make it tighter 

[Dafaseles]

So, this last week, we started to mock up the wiring and amp rack. We can't do too much until the amp and batteries get here, but at least we can get it playing. That's a kicker CXA400.4 standing in for the mids and highs. There's a passive crossover in the doors protecting the speakers until the new amp comes. 

We also have the enclosure pretty much put together

It's a biggun 

Building and fitting up some beauty panels

And getting the sides and top ready for fiberglass and foam. 

That's where we are now. Hopefully make some more progress next weekend. 

[Dafaseles]

 Quick little update. 

We both weren't able to work on the vehicle this past weekend due to my buddy getting covid. It's been kicking his butt. He's been working on the build when he can though. 

He installed a temporary wooden dowel, top to bottom, for support. One I'm able to talk to my welder, and get measurements, that is going to be replaced with a steel cross. To to bottom, front to back. 

He also did some vinyl work. I like the crome buttons, and the pillow look, I just wish the buttons where a little more uniform in spacing. But, he likes it and that's all that matters. 

He also installed the black light LED's.i think it turned out dope! That Skar logo on the back is actually invisible without the black light on. It also makes a cool purple effect that I like. 

[Marchant89]

Damn dude makes me want to move beside you too 😆😆