Project Time: 8-20 hours
Project Complexity: Professional
Project Cost: $100-$500

Overview
I tried a few boomboxes, and the sound was not tolerable. I set up a pair of stock B652’s and a Lepai 20W amp. The sound was better than a boombox … which is not a hot recommendation. On that day my neighbors started showing up and asked what was going on. I started pouring homebrew and we wound up having a great afternoon talking and listening and delighting in the malty aroma of the brew kettle. Then it struck me that I could build a portable system out of the pieces I had laying around with only a few critical purchases. The porta-partty idea was born. DESIGN GOALS :: 1) portability, 2) sounds better than a boombox, 3) use up junk laying around my workshop, 4) keep new purchases to a minimum, 5) accommodate two internal and one external source, 6) play duration = five hours, 7) detachable speakers, 8) CD/storage bay, 8) charge port access. Note : my SLA charger can go up to 23V to overcome internal battery resistance. This voltage will zap the Lepai. A break-before-make switch isolating charging and operational voltages is mandatory. ARTISTIC GOALS :: 1) Tron theme to play off the blue volume knob, 2) match the modded B652’s. PARTS ON-HAND :: pair of stock B652’s, Lepai 20W amp, CD player, Nano2G, CD tower, 6” waffle grills, vintage voltmeter, 2 pairs of Peavey rubber feet, various wood scraps and cab stuffing, plus a zillion little bits and pieces and sacrificial cables in my parts bins. PURCHASED PARTS :: 1/8” stereo panel mount jack, 12V 7.5AH SLA battery, XO parts, 1/4” MDF for the enclosure, 3/32” Lexan for the upper and lower panels, a sturdy handle, magnetic “tape”, hinges and mounting adhesives. BUILD :: formal plans/schematics not included. CorelDraw was used for the artwork. Generically : the enclosure was sized to house the battery, amp and sources, plus storage bay. Battery placement is critical for overall balance while carrying the box. I used CA/5min epoxy almost exclusively rather than brads/screws/staples. Specifically : B652 mods = XO and stuffing per Chris on PE chat, plus waffle grills. Enclosure = overall dimensions are 8.5” X 6.75” X 12.5”; see pics for framing, internal frame to mount the amp that also anchors the battery, a slide out tray for the CD player and iPod; the CD bay is an 8” piece hacked out of a CD tower. Paint job before final assembly. Panels = drilled per layout (see pics). The main panel is screwed down tight. The CD bay and source drawer live behind the hinged upper panel using mag tape like a fridge door. Wiring = follow schematic. Back pane = routed speaker cables through notches then screwed it down tight. Detachable Speakers = added Velcro between enclosure sides and B652s. Partty Time ! IMPRESSIONS :: the audio quality greatly exceeded my design goal of “better than a boom box” as stated by many listeners, professional and casual, both indoors and outside. The box is sturdy and rock solid. The artwork and theme are well received by all. I am glad to be using the CD player and Nano2G after mothballing them for years. Although portable, it’s not that road-worthy, but the Velcro holds super tight. I hope this project gives you some ideas. Dig around your parts bin, buy what you need to, and build your own custom porta-partty !!!

About The Designer
My first degree was in Electronics. When I got outsourced, I got a Bachelors in Nursing with Psychiatric focus. As a result, I can repair schizophrenic analog circuits really well. Sometimes I just talk to them, and they start working within normal parameters.

Project Parts List