Building a mobile audio cooler

Discussion in 'General Car Audio Discussions' started by Korporat Avengr, Apr 6, 2012.

  1. Korporat Avengr

    Korporat Avengr Full Member

    I saw a picture of a mobile stereo system someone made, and they took a large cooler, cut holes out of it and mounted speakers, a 13" sub and a deck. It was loud and can play for about 7 hours on its own. I want to build the same thing, and I have a ton of aftermarket car stereo stuff Im not using. It would be nice to have a loud system you can take anywhere you go, and move it into different vehicles. I saw this project on JL Audio's facebook page. I want to get some ideas on this before I jump into it.

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    Besides buying a big new cooler, what other type of enclosures could I use that would be sturdy and somewhat waterproof?
    I assume it runs off car batteries mounted inside. I have a Kicker L5 12" that I want to use, but I know a shallow mount sub would be the way to go. I want to use 1 amp for 2 speakers and the sub. I have a 3 ch and 4 ch amp, would the 3 ch be better?
    How many car batteries should I use?
    What should I do for a ground?

    I havent done a lot with mobile audio and electronics before, so this is kind of new to me. Please let me know if you have any ideas on building this.
     
  2. wingless

    wingless Full Member

    The big disadvantage to using a cooler for an enclosure is that it is designed to resist heat flow. The amplifier and charger inside the box get hot. The battery does not like heat. The addition of properly-placed ventillation holes that do not compromise the strength could mitigate that disadvantage.

    The advantage to a cooler is the enclosure weight, strength and the wheels.

    An AGM battery is a good choice over flooded cell because it cannot spill. My boat now has six of these Lifeline GPL-31XT group 31 AGM batteries. I selected these because they have ~25% more capacity than all the other group 31 batteries. These provide 125Ah capacity. These weigh 74 lbs each.

    A properly sized built-in charger is appropriate for this mobile sound system. The Charles 5000 SP charger I use on my boat is very good. Select a charger with appropriate current output and profile for the battery selected. Use the battery manufacturer's specs to select the right charger. The charger should be near the battery so the internal thermal sensor can modulate the output based on battery temperature.

    Use marine speakers and a marine head unit so the waterproof requirement is satisfied. My intro shows the parts I used on my boat, but there are lots of options.

    The thermal issues and the battery capacity / run time are the biggest issues that must be properly addressed. Run some ballpark calculations for both and that will help this work out.
     
    Last edited: Apr 7, 2012
  3. Korporat Avengr

    Korporat Avengr Full Member

    I dont need this to be totally waterproof, I just want something I can strap in the back of my Rhino and go off-roading or take places where i can play music loud.
    The price of those battery chargers is out of my range, where can I find cheaper ones?
    I was thinking of charging the car/marine battery(s) in the cooler with a regular car battery charger that plugs into an outlet, not an on-board charger.

    I am going to use a Kicker 12" L5 sub and 2 Rockford 6x9 speakers, all powered by a 3-ch kenwood amp (does that work?), or the sub powered by a 500w 1-ch amp and the speakers running off the deck. HERE'S MY QUESTION: Does the sub need to be sealed off from the speakers or other components in the cooler? If so, should I create a vent for the sub?
     
  4. wingless

    wingless Full Member

    Pick a battery, then select a charger that is appropriate for that battery.

    The AGM batteries like lots of current, per the specifications, so a charger w/ a NEMA 5-15 plug might not be sufficient.
     
  5. Korporat Avengr

    Korporat Avengr Full Member

    I am hooking up the head unit...how do i connect it directly to 2 speakers and to the battery?
    For the head unit and amplifier grounds, should i use the negative battery terminal for that?
     
  6. wingless

    wingless Full Member

    Yes, use the battery negative.
     
  7. Korporat Avengr

    Korporat Avengr Full Member

    Ok do I need a fuse for the wire going from the deck to the battery positive terminal? the manual for my head unit shows a fuse inline with the red and yellow wires before they connect, and then the car's main fuse box after they connect, before leading to the battery. What should i do here?
     
  8. wingless

    wingless Full Member

    Yes, follow the wiring diagram.

    For safety the fuse should be close to the battery.

    All the wires should be secured along the length. All the wires should be secured so that they cannot short to anything bad if a failure happens, like the crimp lets go.

    The Adel clamps or the nylon wire ties w/ screw holes are common ways to secure the wiring.

    Use a high-quality crimp tool, high quality connectors and high quality wiring. I like to use marine wiring everywhere.
     
  9. Korporat Avengr

    Korporat Avengr Full Member

    Is there a way to connect the amp power wires to a power source other than a battery?
    battery charger, jumper, wall outlet, custom wiring...?