Intro: DIY Boombox With Car Stereo Head Unit
So here is my Pelican Case Boombox, what is known between my friends and I as the "The Big Ass WTF!!!! Box"
This took me 2 days to build but it can be done in less time if things like this come easier to you.
The features of the box are!!!!!
ONE!!!! Voltmeter installed on the upper left corner to allow you to see the power drain and if it needs charged or not. A charging port so you can recharge the batteries or just run it from the charger. The first toggle switch powers on the head unit and the voltmeter. The head unit has an AUX cable adapter (you do lose sound quality with this option), a USB port for your phone, and bluetooth built in. The second switch powers on the VU Meter. The last 4 switches allow isolation of each speaker, so you can either use all 4 speakers and enjoy the build to its full potential or conserve power by using 2 speakers at a time. Also it helps if you're getting a buzzing sound and unable to locate which speaker it's coming from. The VU Meter has many graphics to choose from and you can download more graphics to choose from.
To build this box you will need these parts:
1. Pelican 1650 case with pluck and pull foam
2. JVC KDR950BT Head Unit
3. EVOR04 VU Meter or whatever VU meter you choose for your taste
4. 6 Toggle Switches, I used 1-Red, 1-Green, and 4-Blue
5. Green DC Mini LED Voltmeter
6. A pair of DLS M225 Crossover speakers (5.25" speakers)
7. A pair of DLS M369 Crossover speakers (6x9" speakers)
8. Two Chromebattery 12v 9ah batteries wired in parrallel.
9. T-Tap Connectors 22/18 gauge (Red Connectors)
10. 22 guage wire
11. 22/18 guage female quick disconnects
12. 2.1mm x 5.5mm DC female adapter
13. A Yuasa 1 Amp automatic battery charger
Step 1: Figure Out Placement
When first building this box, you want to figure out the best placement for the hardware that looks the best for you tastes. Do that by either drawing out sketches of where the placement should be or you can lay them out as I have in this picture.
Step 2: Cutting Out the Holes
When cutting out the holes make sure you use the outlines provided with the speakers. I used a smaller hole cutter to start out the process and then finished in up with a jig saw. If you use a pelican case like I have make sure to set it to a low setting as it will cut through the case very easily. After you've finished you can use a box knife or an exacto blade to clean up the edges. Ensure that the rubber on the speaker has enough clearance not to rub against the edges as this can damage them.
Step 3: Installing the Volt Meter
You can place the voltmeter anywhere on the unit, or not use one at all. I do highly suggest using one so you can see how much power is left. When mine drains to around 11V that's when I plug mine in just because I don't want to strain the batteries more than necessary. It can go below 10V. To cut out the hole I put the screen face down on the box and traced around it with a sharpie and then used the smallest drill bit I had to drill holes very close to each other just inside the lines. After drilling I used an exacto knife (be careful not to break the blade) to slice between the holes. As you're smoothing it out, try and fit the meter in the hole. This will take a little time as the wires do get in the way a bit but you can make a nice tight fit with patience.
Step 4: Installing the Batteries and Charging Port.
To power this project I used two 12V 9AH chrome batteries ran in parrallel. I used the pluck and pull foam that came with the box, the foam holds the batteries in place very well as long as you make the hole a little smaller than the batteries.
To run the batteries in parrallel you'll have to wire them together with the positive terminal to positive terminal and the negative terminal to negative terminal. Before making the soldered connection between them make sure to install the charging port. This will save you wire and time in the end.
The charging port is a 2.1mm x 5.5mm female adapter. Now these are threaded and meant to mount directly to a box or whatever you're using them on but the pelican cases are thicker than the threads are long. To resolve the issue without causing excess damage to the box I used a small piece of sheet metal and mounted the plug to piece of metal, then mounted the piece of metal to the box (which you can see in the pictures). I used a drill bit just slightly larger than the plug to ensure it would be easily accessable, you can hot glue around it to make it look better or just leave it as I have.
To wire up the charging port you'll need a voltmeter to test which prong is positive and which prong is negative. Or, if you're able to, you can find the correct terminal with online diagrams. If you have a 2 pronged adapter though, remember, 99% of the time the outside of the adapter is the negative while the pole in the middle of the plug is the positive. But please be safe and use a voltmeter. And don't mix up your wires afterwords, I accidentally did this and spent another hour trying to figure out what went wrong only to discover in the end I wired it backwards.
Now that you're batteries are in place and the charging port is installed just wire everything together. Remember for the battery though, to run in parrallel you must connect negative to negative and positive to positive. If you wire it +/- you will get double the voltage but the same amp hours, this is called in series and if you're units are not rated for 24V you could damage them. I highly suggest soldering everything together and using heat shrink to cover the exposed wiring.
Step 5: Installing the Head Unit
To install the head unit you'll need to use the provided bracket and trace the inside of if to cut out the correct sized hole. You can use a Jig saw to cut out the hole or use the same trick I used to cut out the hole for the volt meter. When cutting, I always suggest to make the hole slightly smaller than necessary and to then use a sharp blade (Exacto knife or box cutter) to shave away the rough edges and to allow for a tighter fit. Once you're able to to fit the bracket, there are tabs around the entire thing and if you push these out it will hold the head unit in place tightly without the need to fashion brackets and drill additional holes in the box.
To wire it in, follow the instructions that come with the head unit. In my experience installing systems in cars, the red wire is the wire that will go to the ignition or in this case the toggle switch to power on the unit and the yellow wire is connected directly to the batteries to keep the settings that you input in the head unit. Do ensure before hooking up the power you ground the head unit to the batteries. By this I mean after wiring is finished connect the ground then the power*
Step 6: Wiring the Speakers
If you get crossover speakers you will have to use the wires that come with the sets. They come with specific wiring that protects the units from being damaged. The instructions specifically say it will (not might) damage the tweeters if you don't use it.
To wire it in just follow the diagram provided with the head unit. If you use individual toggle switches for the speakers like I have, I wired the speakers to the toggle switches and then wired the head unit to the switch creating a point where you can put a break in the circut shutting off speakers as you choose or using all as you please.
So the order will be as follows:
1. Wiring from head unit to toggle switch
2. Toggle switch to speakers
3. If toggle switch has an LED on it, ground to battery.
4. Follow 1-3 for all speakers.
Step 7: VU Meter, How to Wire In
As you can see on the picture, it has lables for how to properly wire it in. It does require 3 grounding wires to properly work and a power line in. To wire the speakers in I just used a T-Tap 22/18 guage clamp on the positive wire for the speakers after the toggle switch to the VU meter. It's fairly simple and straight forward.
Step 8: The Foam
Once you've completed wiring everything in you'll have to pluck out sections of foam. You don't have to use the foam but I did to reduce rattling and movement of the units. If used, ensure to allow plenty of space between the foam and the head unit, the plate on the back of the head unit gets really hot. The foam will help to dissipate the heat but do not allow the head unit to come in contact with it as it could melt the foam and cause a fire or melting of the wires destroying your box. You can see in the picture how I plucked mine out and ran it for 5 hours straight at a BBQ with no problems. To pluck the right spots it's as simple as lower the lid and leaving a light impression on the foam or using your hand to find the right spot to pluck. The second layer of foam also helps to hold the batteries more firmly in place as well without the need to drill additional holes in the box.
Step 9: Finished Product
As you can see, everything now lights up and turns on (other than the top left speaker switch which I did replace in the end).
You can see some of the graphics that the EVOR04 offers, these are not all the graphics offered but just some of my favorites...
I hope you enjoyed this build and it inspires you to do you own in the future, if you have any questions on how to do it or if there's anything I might have not explained well enough please message me and ask.