Sharing music with friends through laptop or smartphone speakers can be less than satisfying, which perhaps goes some way to explaining the overwhelming choice of portable Bluetooth speakers that come into view as you enter a consumer electronics store. Such offerings all suffer the same problem, though. Just as you're getting your groove on, the built-in battery dies and you have to wait hours while it juices up from a wall socket. What mobile music lovers like me need are wireless speakers that can charge in minutes, and then last for hours. An impossible dream? Sam Beck from Portland's Blueshift doesn't think so. He's developed mono and stereo portable Bluetooth speakers powered by supercapacitors. Helium users can look forward to a super quick charge time, hours of full volume playback and years of recharge cycles before needing to consider a supercap refresh.

The 12 x 7 x 4 in (31 x 18 x 10 cm) Helium Mono packs four Maxwell BCAP0350 supercapacitors, each about the same size as a D-cell battery, and a single 4-inch Fostex FE126E full-range driver in a hand-made ported bamboo cabinet tuned to 105 Hz. The Helium Stereo unit doubles the number of supercaps and speakers and measures 18 x 9 x 6 in (46 x 23 x 15 cm). The speakers, which can be fronted by removable grilles if desired, are driven by a Class-D amplifier, and are capable of handling all audio frequencies, though there may not be enough low end for some tastes. Beck tells us that the "bass is not thumpy or bone rattling, but it's there – I listen to a lot of Young Jeezy and this handles it great."

Wireless streaming from smartphones, tablets or suitably-capable computers and laptops is possible thanks to integrated Bluetooth 2.1 with A2DP, and AAC and Apt-X codecs. Helium users can expect a good 6 hours of full volume playback before the juice runs out, but it's reported to take only 5 minutes to charge up the supercapacitors, so by the time the drinks are mixed and served, the party is ready to resume. Music can also be fed directly into the Helium speakers via a 3.5 mm audio input port.

The Blueshift project is open source, meaning that the company will freely share plans and schematics so that tinkerers can build their own speakers, or modify the design to suit personal needs or tastes.

With many battery-powered wireless speakers available at the moment, users cannot open up the portable box and refresh the cells when they start to reach the end of their useful lives. The Blueshift speakers are built with longevity in mind, and users can swap out supercaps when they start to show signs of age, though it could be a long while before such things are necessary.

"You could replace the caps, but I don't think you're going to need to," says Beck. "The rated lifetime is 500k cycles/10 years, but at that point they should still have 80 percent of original capacitance, and moreover that's 100 percent of their rated current and max temperature. This application really isn't that demanding, they should last a really long time. I've been saying 20 years, but I expect more."

Blueshift has launched a crowdfunding campaign on the Portland-based CrowdSupply platform to get its speakers into the hands of portable music lovers. For a pledge of US$180, backers will be supplied with all of the bits and pieces needed to make a supercapacitor-powered wireless speaker, but makers will have to supply their own speaker driver and build their own cabinet.

The first 25 fully-assembled Helium units are going to be built mostly in-house, but these have already been snapped up. The next level represents the first speakers that will be built by contractors. A single-speaker edition is pitched at $400, with the stereo model coming in at $150 more.

If all goes as planned, the first Blueshift speakers should start shipping in February 2014. "After the campaign succeeds, CrowdSupply will keep selling as a regular ecommerce site, plus I'll sell direct through my site," says Beck. "Pricing will be around $450 for mono and $600 for stereo."

If the funding goal is not reached by December 19, however, backers will not be charged and Blueshift will look at other ways to get the speakers out to those who want them.

The video below details what the campaign is all about.

Sources: Blueshift, CrowdSupply