After a few odd but inspiring adventures with a few friends came to the conclusion that we must dress up in animal onesies and dance around the Virginia Tech campus on weekends. In order to blast some sweet dancing tunes we needed a decently loud system. At first I connected a LiPo battery to my 150w computer speakers but they weren’t really all that loud outdoors. Next I tried a battery powered PA speaker, again, not really that loud. So after some research I decided to build my own boombox using budget car stereo equipment.
During researching the options to house the equipment I ran across some pictures of boombox suitcases, pretty sweet. After a few weeks visiting the local thrift shops I found a decently sized and decently appealing pleather suitcase and began design work and construction.
The suitcase came a bit worn with blemishes, but for $8 I’m very happy. Although I looked for a tweed hard suit case, they were expensive at $50 and falling apart.
Enough space inside to hold the speakers and the electronics.
Here are all the speakers and components ready to go. The important note is that the amplifier is a class D which is more efficient than class A and B amplifiers, which is crucial for the best battery longevity. The batter is a lead acid battery that provides enough peak amps and amp hours for our needs. I could of gone with LIPO batteries but the lead acid can handle more physical abuse.
All the internal frame parts designed in AutoCAD and ready to be cut.
The back plane and other parts all cut and ready to go. I decided to bring my laser engraver with me during my stay at Virginia Tech, a great decision!
All the parts are cut and ready for assembly. Cut from 3mm Baltic birch plywood. Sanded with 180 grit for a cleaner look.
Speaker holes cut.
The speakers mounted and the air boxes being glued into place.
Starting to come together!
I noticed some sagging of the back plate into the suitcase due to the weight of the speakers and subwoofer. Luckily the suitcase has a metal bar running along it’s frame. I added a stopper bar that prevents the back plate from falling into the suit case.
The amplifier and battery mounted and the wiring process has begun.
At the top shows the controls wired. A few on/off switches, a volume adjuster, aux cable socket, and a volt/amp meter.
This picture shows the shunt for the amp meter. The unit did not really need an ammeter, but I since it was cheap, I thought it would be neat to see how many amps are drawn at full blast.
The wiring complete. The loose red wire is for the secondary amplifier for the rear speakers. I decided to hold off installing them for now because I want to make sure the boom box does what I want it to before the extra time is expended.
Flipping the power switch for the first time is both exciting and terrifying. So many loud pops and puffs of smoke from my childhood, yes, I was an odd kid. Here’s the control panel. The red switch is for main power, the green switch is power to the future rear speaker system, and the blue switch is the for the future Aux/Lighting. The volt/amp meter works rather well and is crucial for knowing when the battery is nearly out of power.
I did not manage to find a retractable handle until after a few weeks of using the boombox in the field. This picture shows about 3 semesters worth of of wear and tear. The handle is black anodized aluminum and shows the scratches from pulling up the boombox over street curbs.
The casters are separate from the handle and are of decent quality. You can really see that we used this boombox quite a bit. The boombox weights about 40LBS and rolling the boombox versus carrying it is a day and night difference.
We dragged the boombox around campus for four semesters now and let me tell you, wow, I am very happy. The volume is very loud and I run it mostly at 1/2 volume. We dance for two to three hours a session and the battery life holds up just fine. At max volume I calculated the battery life to be around one hour, but since volume and power is logarithmic and we found about 1/2 volume to be sufficient, we see greater than originally expected battery life.
The sound quality is not the best, but for a cheap, loud, and portable system that fits our needs the sound quality is acceptable.
A Bluetooth receiver was finally added as our smart device headphone jacks are no longer.