With summer on the horizon it’s time to start thinking about outdoor leisure. [x2Jiggy] is chomping at the bit having recently completed this project. It’s a portable stereo that also gives you somewhere to sit.
Unlike several of these types of project, he didn’t build the system inside of a cooler. Instead, the chassis was built from scratch using MDF. This material is strong and easy to work with, but we’d bet the finished case is a beast to haul around because of the weight. At least there’s a heavy-duty handle on either side so that you and a buddy can split the burden. One nice perk is that it’ll make a sturdy yet comfortable seat thanks the padded and upholstered top.
The audio components that went into it are all automotive parts and shouldn’t mind being jostled during transport. A computer PSU provides the 12V needed by the stereo. But there are a couple of external rail connections if you want to haul around a 12V battery instead.
I prefer to build these things using rechargeable Li* batteries and class D amplifiers, you get away with a fraction of the weight and the same power.
Lugging lead acid batteries around is just like, well, carrying lead around…
because lead acid batteries are cheap. they also have a tendency to not explode/catch fire, unlike Li* batteries. for prototyping lead acid is wonderous. if you then really find the weight to be a bother you could switch over to Li*, but that entails a lot more circuitry than lead acid.
Funny, people constantly bring up the fire hazard of Li*, but i have never met anyone who has managed to set fire to any low current lithium battery, a couple of people have managed to burn high current (RC aircraft) batteries, but those are entirely a different story.
As long as you have protection circuits and a proper charger the risk of something happening is extremely low.
Lead acid batteries are way way way cheaper, especially if you need 20+ amp hours at 12v, and for something like this that isn’t going to be carried very far there’s pretty much no downside.
and class D amplifiers are horrible for sound reproduction other than the low range, since the transistors are being turned on and off at a high speed it can only sample so many times for the high frequencies
ex. say the speed is somewhere 200,000 times / sec
20,000 hz sound wave is only sampled 10 times a sec
10,000 hz sound wave is only sampled 100 times a sec
a class a/b amp is much better suited for the task as it’s slightly more efficient that it’s not completely on but it’ll not be switching so much that you lose the sound quality in vocals as much
Never really got why people use a car stereo for things like this. There are plenty of much cheaper better amplifiers on eBay. Also little modules that have an FM tuner and play mp3s and take a line input. Only thing missing is Bluetooth but again there are modules available for that too.
It appears he used what he had sitting around. You are right, there are better ways to do this, but he did it on the cheap and it does the job.
He’s not using a car amplifier, he’s just using a head unit (using the built in amplifier in the head unit/cd player). Looks pretty good to me. Only thing I would worry about is if it got any liquid on the enclosure it could cause some swelling (MDF is good at doing that when wet) of course the pain probably protects it some and mdf swelling is the least water could do considering the electronics lol…
A big bag of silica gel should sort that out for a good long while. If it’s good enough for transporting top end audio equipment across the ocean in a shipping container then it’s good enough for almost anything
Depending on what country you are in, AC voltage is anywhere from 100 to 240 volts. All cars and light trucks run 12vdc. Car tuners walk allover most home tuners. Sadly, how many home systems do you hear 2 blocks away everyday? The player components are ruggedized, compared to home players. Most home units are a rack-box with a lot of air inside. Car=compact to a tee. 12 volts comes from many sources direct. And yeah, a Tripath amp and lithium is the way to go if that is all needed with a phone-player.
I was gonna do one of those for camping trips… but use a marine radio I used to have in my Jeep. And integrate a solar charging system.
The PC power supply on this shouldn’t have been mounted so low. It’s going to get a ton of dirt kicked into it.
While you’re making changes, make the seat on top hinged, and under the seat, put a cubby hole with a power point where you can charge a cellphone or something. Maybe make it lockable, but it’s probably easy enough to steal the whole thing instead of breaking into it.
great for playing the brown note, better with a tripath tho.
I think I would have tried for more of a recessed mounting for the head unit as well.
People build ruggedized projects and then leave stuff hanging out where it is exposed to…everything.
cool build, add wheels and an extendable handle and you’re all set.
Very good idea. I hadn’t even thought of that! But it would make it a lot easier to lug around. Although would that cause any issue with the liquid inside the battery swishing around?
I wouldn’t think anymore than one riding around under your hood.
From experience of building something similar, I’m still going with the car audio components. They sound great, get loud in open spaces, and if done correctly, maintain clarity. I dont think this was built for an audiophile, but it fits its purpose. The toolbox version I made, was brought to work. I work in a factory where there are a LOT of hazardous materials that would destroy any store bought stereo. My speakers are recessed, and covered with something more than a stocking, its rugged, and is the only “portable” stereo my co-workers have seen that can play over the machinery running.
Kudos for the nice build. My only comment would be to add a fine screen of some sort to prevent nasty abrasive stuffs from getting around the posts in the center of the 2way(3way?) speakers. Any grit at all will make it sound terrible.
Awesome build. I absolutely love it. Hats off and kudos to you.
I was thinking of building one similar. I am still pondering adding retractable wheels to one end, to make it like a roll behind cooler.
This speaker does look quite bulky. I think it would be better if you could wheels that lock in place to the unit. This would make it much easier to transport from your home to your boat or any other place you want to crank up the volume.
Awsome. Such a cool idea.I have a Kenwood Class D amp at my store room. It’s time to make something with the old machine. :D
Thanks for sharing it.