The MonoBox on the left is John Hall’s prototype which he modded with a status LED powered by a 9V battery. On the right is Scott Vincent’s MonoBox mod built into an ammunition can. He thoroughly documented his build process below.
Weekend Projects makers John Hall and Scott Vincent wrote in with their experience building the MonoBox Powered Speaker, a low current power amplifier circuit built around the LM386. These two builds really epitomize the aesthetic customizations capable with this project, with one version built into a portable rugged metal enclosure (that Scott had to troubleshoot for metal-on-metal rattling) and another version designed to be permanently plugged in. It looks minimalist, but sounds big!
Scott’s circuit, mounted inside his enclosure, a .50 cal ammunition can. Note his battery holder, power toggle switch, and the primary audio circuit mounted to the raised indentation on the enclosure’s base.
Scott’s speaker, a 5.25″ Aura NS525-255-8A mounted on the side of his enclosure. You can see plenty more pics and read about Scott’s process here. The enclosure’s handle provides immediate audio portability!
John writes: “The internals of my second MonoBox Powered Speaker. It has since been glued shut. You can see below the circuit board where I had to chisel out a relief for the power and audio jacks. This MonoBox was intended to be left plugged in all the time, so I added a power switch (seen above the circuit board).”
John writes, “This is my second MonoBox. I bought a Sharp VSP1206FB406E full range (130Hz – 18KHz) 6 ohm 4.5″ x 2″ speaker from Skycraft Surplus. I mounted it in a 6.5″ x 5″ x 3″ craft box, which I stained and finished. (Jo-Ann Fabrics labeled it as a walnut recipe box, but I think it may actually be basswood.) I used 14-count aida cloth (in antique white) for the speaker grill cloth. The thicker (1/4″) wood is perfect for a speaker, and it produces fantastic sound without needing to tinker with equalizer settings.”
Thanks for writing, John and Scott! Did you build a Weekend Project? Send us an email with pictures and a story, and you could appear here on the MAKE blog.
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