Most of us keep our music on our computers and our computers are increasingly mobile, but there's a disconnect between the ability to store large amounts of music on a laptop and the portability of said laptop: laptop speakers aren't worth playing music on. But a clever engineering fix by British company NXT has changed all that, conjuring big sound out of small, portable speakers powered by nothing more than a USB outlet.
Most audio amplifiers – the kind you plug into the wall – maintain a voltage of about 32 volts. That means when the music gets loud, the amp can deliver the required punch. Laptops, which must use power sparingly to preserve their portability, don't pack nearly the wallop; a USB 2.0 port produces a maximum 5.25 volts to external devices, making it impossible to power larger, high quality speakers from a laptop.
Some engineering trickery from NXT circumvents these problems by relying on the simple premise that the USB can deliver 5.25 volts all the time, even though music is not all crescendos. During quiet passages, a pair of capacitors stores unused voltage coming from the USB. The speakers monitor the music signal a few milliseconds ahead of amplification so they can release that stored up power when the interlude is over and the heavy guitar/drum combo us unleashed.
Of course, this technology is a replacement for weaker bus-powered, desktop-style speakers; pretty much any high-quality stereo speaker has an AC adapter. And the power storage is limited; the extended version of Freebird could run the capacitors out of juice, causing the volume to fall. But NXT says they've tested the speakers on a variety of musical styles with consistent success. If they can get some consumer electronics firms to hear them, the technology could be on the market by next year.
That's a Kool Idea. Very smart. Now why not implement it on other similar devices. My PC for example.
so these will drain ur battery?
I'd assume the drain is similar to any external HDD or that Zune your're charging.
Hmmm...I've had a 1 farad capacitor in my car audio system since '92. The only surprise is how long it took for the idea catch on elsewhere.
They shouldn't be any more of a drain than anything else on USB, using 5.25 volts pretty much constantly.
Wish that these articles would get the tech right. It's not the voltage, it's the power -- volts x amps. USB is limited in voltage and current. Continually drawing the max available power and using it in bursts is fairly clever, but again, it's the power. The aquadag voltage on the good old CRT was in the neighborhood of 50KV, but it had almost no current capability, so you would generally survive the shock -- it's the power.
@manhunter098 volts =/= power volts * amps = power power * time = energy. Energy is all we care about. You can run something off 5.25 volts for years and never consume a measurable amount of energy or you could run your house off 5.25 volts and consume roughly the same amount of energy it currently consumes. I wish people would have payed more attention to high school physics.
There is such a thing as a dc to dc voltage converter that can change that 5.25 to 32 volts or 320 volts. These guys idea would work better and would have a reduced cost if they used a battery and a smaller supercapacitor. There is already people making powered speakers with a usb charging battery look up
Manhattan mini USB speakers