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I think I will actually want some music from time to time in this rig, as long as I can hear it over the gnarly exhaust, the transfer case, and the work boot tread noise. It came with "nothing" except that the stock radio area had already been hacked out to a roughly DIN-sized opening, and the lower door panels have been gouged out to accomodate some six-by-nine speakers. There were also a few unidentified wires behind the dash that might be useful for power and grounding.

I have on hand a Pioneer CD player that came with an Audi I drive, which has four built in forty-or-so watt channels of amplification. This ought to be fine for my purposes. Front speakers will almost certainly be a set of my six inch two way HUMAN A-61's mounted over those 6x9 holes. I've had a truck speaker box thing lying around doing nothing for years, so I am going to build up a set of ten inch two way systems in it for the rear.

I identified the wires I need for the head unit while installing my lighting switches - battery, ground and ignition. Well, ok, what I thought was a ground was coming from the brake light switch, but I remedied that with a new wire to a bolt pn the friendly nearby accelerator pedal bracket. I also ran rear speaker wires under the carpet while I installed it. I bought an old (so old the PETE package was disintegrating!) Harada antenna at a FLAPS that is capable of being "side mounted," as that is what these fenders require (the windshield antenna is long gone).

Installing the antenna has taken some thought (and looking at the truck in daylight!). I wanted to put it at the upper rear of the driver's side fender, but there seemed to be no easy way to get the wire into the cab. In daylight I see that anywhere on the fender would allow me to bring the wire out through the many perforations (including between the firewall and fender) into the engine compartment, and then through a grommet in the firewall. As it turns out, the forward "logo mounting" hole (as if I am ever going to buy some Custom Deluxe 20 logos...) is directly opposite a 3/4" hole in the inner fender, so I had a ready-made pilot hole for my hole saw drill. It was easy to route the wire past the wiper motor bits and run it in through the speedometer cable grommet.

Here is what I cobbled together for the rear speakers (I since added a nice "Oldsmobile" logo below mine):

I used fairly efficient and well-made ten inch woofers, vintage horn tweeters I rebuilt and added protective screens to, and custom crossovers I whipped up just for fun (second order on both drivers at around 2 kHz). After screwing it all together, I made up a mockery giant HUMAN logo for the front, and clamped on some hockey-skate-proof waffle grills to protect the woofers. Since the logo is just a bit of paper behind some plexiglas, it probably won't last more than a few months, though.

Here are the boards for the A-61's I'll use in the front. I decided to cut them with the tweeter "off-center" since they will be mounted horizontally - this way the tweeters will be a little higher on each side. I have drilled pilot holes for the driver mounting screws, and for the four screws that will attach the boards to the door panels. I cut the edges with a forty five degree router bit to add a touch of class.

The only question remaining is whether to carpet them or paint them. I'll probably use carpet, since it holds up better, is not that hard to do, and is the way I usually build them for customers. Then again, they are going to live a hard life down there. Maybe I'll cover the whole lower door panel with a three foot piece of one by ten pine, nicely oiled, and paint the speaker boards red to "match" the truck. Yeah, that's the ticket...

Since these are "for me" I decided to use recycled woofer chassis for the new woofers being built here, with butyl surrounds:

The new tweeters are half finished:

One issue with the door speakers is how to get the wires to them safely and securely. My truck, which was once someone's "build it up with spares and stuff" project, has a random hole or two in the front edge of the door, and in the cab jamb area. These holes move apart and together as the door opens and closes, so great care must be taken to dress the wires as they pass through this space. At the simplest, I think I could make the holes larger, to about 1/2" each, and run split-loom through both, leaving it so it can move through the holes to take up the excess. Or, smooth tubing could be used. The speaker wires would run through these conduits from cab to door.

What I have done is to run my speaker wires (which are fatly insulated 16 gauge) through some 3/8" fuel line for protection. I had to drill four holes on each side - one in the door jamb about half way up the lower hinge area (this is two layers of steel), one in the kick panel area level with it, one in the door itself, again at the same height, and one more through some inner bracing metal in the door. These were all drilled large enough to hold rubber grommets, the body ones sized to fit the fuel line tightly so it wouldn;t move, and the door ones for a grommet a bit larger, to allow the fuel line to move in and out of the door as it is opened and closed. A bunch of grommets and raw speaker wire might have been fine, set up to allow the wire to fold in the door-jamb gap. We'll see how well what I did works over time, I suppose.

I had half-way cobbled the head unit in place, and attached the rear speakers to it. It actually worked. Right now the antenna is sitting in the passenger seat and telescoped down, but it still picks up WGBH 89.7 out of Boston, which is no mean feat from fifty miles away.

With the front speaker wires in place and connected to the wires coming out of the head unit, I can fix the mounting sleeve in place and push the unit all the way in, finally. Pretty slick looking...

Finishing up the HUMAN A-61's and installing them is all that is left, really. Guess it's time to go measure and cut those three foot by nine inch boards.

Here are what the HUMAN part of the door installation looks like:

And the boards that will cover the lower door section, awaiting their covering of fur:

You can't see it well here, but I also cut a chamfer around the edge of these.

I would like to find some nice solid, easy to mount storage bins to attach to the rear section of these - a handy place to put things like gloves and tools before climbing into the truck.

Now I am covering the door panels with fur. I used 3M "Super 77" spray adhesive, which works very well for this sort of job. I have used it many times over the years and it holds up well in the harsh automotive environment. I spray it on the back of the fur and on the particle board substrate, let it dry a few minutes, and then it grabs strongly and smoothly. After attaching the main face, I cut the fur so it will butt nicely where it wraps around the corners.

Here I have wrapped it around the chamfer and the edge:

Left: the back side showing how I wrapped the fur around, again slicing off the excess where the pieces would have overlapped..
Right: I sliced little triangles open around the countersunk mounting holes to make installation easy.


Now I go out the truck, drill pilot holes in the metal and screw down the door panel boards (I used a spring clamp to hold the board in place while drilling the first two holes). You can see my little flaps have covered over the screw heads nicely. Also clearly visible in this photo is the 3/8" fuel line I used to protect the speaker wires as they pass through the holes I drilled in the body and doors.

And now I put female disconnects on the speaker wires, plug in the A-61's, and screw them in place.

They are so pretty I took a couple more photos of the final installation:

Well, everything is installed now, and plays correctly. The big question is, after all this work, how is the sound quality? Generally, it's not too bad. The tens in the truck box are a bit constrained by the small volume, so their bass is a bit punchy, but not obnoxiously so. The door speakers image nicely, and are much flatter overall than the "West Coast sound" of the box in the rear. The weak link right now is that the doors are crappy speaker boxes. They are too big inside to complement the low frequency response the HUMAN PRO 007 woofers are capable of, there is no damping material to break up and absorb the back wave, and the metal itself has nothing done to it to stop it from vibrating along with whatever frequencies it likes.

Also, the little "45 watt into 4 ohm" amplifiers are struggling mightily to make much volume into these 8 ohm speakers before they start to distort noticeably. They play loud enough, of course, but they don't go to the "really loud" place these speaker are capable of. I can always add a bigger external amplifier if I decide this matters to me, although I doubt it will - after all, this is a work truck, not a cross country cruiser.

So overall, the sound is pretty decent, taking into account the things I mentioned above. I do want to get some less ugly door panels at a junkyard one of these days, and I think that when I am installing them I will do a few things to mitigate the front speaker cabinet, um, resonant door problems. I might install a board blocking most of the air passage between the bottom and top, although I will have to take into account that water runs into the door past the windows. Some damping material would be nice, too, but again, I might run into water problems - although, fiberglass and polyester are both pretty immune to water damage. I can definitely slap some sticky goo sheets on the metal panels to lower the "steel drum" effect.