Description

I am building a portable sound system, able to withstand outdoor conditions. It is self powered, but has an SAE connector so I can connect it to a vehicle battery, cigarette lighter, battery charger as a secondary power source or to charge. It contains an amplifier with an integrated Bluetooth receiver, SLA battery from an old UPS, a small voltage meter and a waterproof power connector, all in a watertight container.

Details

I wanted to make a portable outdoor sound system that actually sounded good, and could be heard.I didn’t think this was much of a hack, I am just connecting off the shelf stuff, but a friend said I should send it to hack-a-day. I go camping(if you can call it that) every year at the Texas Renaissance Festival, which is really more of a huge outdoor party. I usually rent a trailer and invite a bunch of friends. In the past I would bring a stereo or speaker dock, one year I bought an old car cd/mp3 player deck wired up to some random speakers from a home sound system, but that one didn't hold up to well to the random showers, hot(day), cold(night), dusty, damp conditions(and drunk people). The portable stereos I have brought are never loud enough to overcome the sound of the generators, and everyone else. Last year we were watching a movie on a projector and could barely hear the movie just a few feet away from the speakers. So this year I decided to go big, or go home. I had been thinking about this build for a while, but finally starting putting it all together when I found a small amplifier on sale at woot for $60.

Pyle Bluetooth Marine Amplifier, 1200 Watt 4-Channel Water Resistant Amp

I had originally planned on using a bluetooth receiver(that I also bought on woot) but this amp comes with one included. So next I started playing with it, wiring it up to old speakers I had laying around and a SLA battery from an old UPS. I also had an old 6 pack cooler that was missing a lid, so I used that to carry it around, and eventually decided it might make a good enclosure.

Next I bought a pair of cheap marine grade speakers, they were $45, And some cheap boxes to put them in, for another $25.

6 x 9 Marine Speakers

So now I have all the basic parts, and wire everything up. Everything sounds good, even though I just have wires twisted together at this point.

I start planning out everything in my head, and found a waterproof power switch I had laying around, I bought a small voltage meter, a surface mount SAE connector, some other parts to put it together, and cut a piece of clear plastic to be the lid.

Components

1 × Amplifier/BlueTooth receiver Saw a deal on woot, i dont usually like buying Pyle stuff, cause it always seems to crap out, but we shall see.

1 × 6 x 9 Speakers Cheap pair of Marine Speakers. 4 ohm, 120w rating

2 × Speaker Boxes Cheap $25 speaker boxes, if they get wet and fall apart, I will just get or make better ones.

1 × Small Voltage Meter DC 2.7 - 30V

1 × Surface mount SAE connector To plug in a charger or extension cord to a car cigarette lighter.

Project Logs

Collapse

Field Testing
bryanlc • 10/30/2015 at 13:45 • 0 comments

I brought it to RenFest last weekend. It poured down rain all weekend, I'm glad I tried to made this thing water-tight. The only issue I had was the waterproof speaker connectors. The plastic I used for the top is actually too thick for the panel mount part, I had tried counter-sinking the hole to make it fit, but one of them fell out of its hole. But because almost everything inside is water-resistant, it continued to work fine, even full of water.
I estimate we used it for about 20 - 30 hours before the batteries got down to about 10v. I planned on taking the top off and letting it dry out, but it was already dry inside the next day after getting back.
Annoying my roommates and neighbors
bryanlc • 08/10/2015 at 13:36 • 0 comments

I bought way too much wire, and overkill waterproof connectors, but it all works.
I still need to drill a big 3 1/4 Inch hole for the control panel, and attach the voltage meter to something.
I tried adding another battery, but I think it was bad. I swear I checked the voltage(although it may have been months ago), and attached it correctly, but it is showing 0-1v now. It was most likely bad, I know its from an old, failed UPS.
I also tested out using my sub on the 3rd channel, and the two old 6.5 inch speakers on the 4th. It sounds good, but I think it could use more bass. I don't know if bridging the second two channels will make is sound better, or fry my amp, so I haven't tried it yet.
Battery test and speaker connections
bryanlc • 07/27/2015 at 17:09 • 0 comments

So after using the stereo, and running the battery down, way too far, I figured I may need to put in some sort of low voltage shut off. I was also planning on wiring up the voltage meter, but I cannot find it. So I bought another one, and while I was at it, I bought 2 of these waterproof plugs, for the speaker connections.
They are overkill, rated at 30A at 500v AC, but they should work.
More Speakers!
bryanlc • 07/24/2015 at 15:35 • 0 comments

So now I still have 2 audio channels available, I think it could use a little extra bass. I have an old Sub, and a low-pass filter. I was thinking about attaching 2 6.5 Inch speakers and the sub on the same two channels, but I’m not sure how that will work yet, I am not sure how this amp will handle being pseudo bridged, I am good with simple electronics but audio stuff sometimes baffles me.
So my thinking is, I will connect the second left and right channels to the two 61/2 inch speakers, and the low-pass filter then to the sub, making a weird 3-way(or 2-way) mono speaker from a stereo connection. I guess i will just have to try it and home it does not blow up.
Kinda like this:
This is an old Subwoofer from a 2.1 computer speaker system, the main board eventually fried, so I yanked it out, and wired straight to the speaker, and taped over the holes for input/speakers/stuff.
These are two speakers my dad made when he was a teenager, they still work even though they have been in his garage for a few decades, and still sound ok. I think he had the polarity backwards on one, and I am not sure if the holes he drilled into the top are acoustically correct, but whatever.
Initial Testing
bryanlc • 07/24/2015 at 15:34 • 0 comments

I have the main parts wired up, tested it last weekend. I had a few friends over and we were playing music all night, I hope we didn't piss off the neighbors too much. Battery lasted all night, and part of the next day, although I hadn't charged it for a few months before testing, but it still had a good charge.
The system sounds good.
[PICS OF CURRENT PROGRESS]
I cut the acrylic with a hack saw, so its not perfect. It was a piece of scrap i found in my dads garage, and it was late at night so I didn't want to use a power saw. I plan to sand it down and try to make it look better.