The Edifier MP250 is a single unit, and a thing of beauty. Its body is largely one piece of formed aluminium, naturally coloured, while its front and ends are black. This is a long skinny gadget, stretching 261mm from end to end, but stands only 36mm high and 44mm deep. On the left-hand side is the mini-USB connecting socket where both power and audio (in digital format) is conveyed to the unit. There is also a 3.5mm stereo socket for analog sound. On the right-hand side is a glowing blue LED and a single button (which looks a lot like the power button on an Apple Bluetooth keyboard).
Under the grille are five loudspeaker drivers making this a full three-way system. Four of them are 32mm circular units, two deployed as tweeters for high frequencies, the other two as mid-range units. The final driver is 75mm wide and 32mm tall, and acts as a "subwoofer", so says Edifier.
Setting it up was a mixed affair. Getting sound out was easy, of course. We just plugged it into a Win7 notebook, waited a minute or so and had sound emerging from it. The difficulty was where to put it. In front of the computer? Then we'd have to hold our wrists above it while typing. On top of the screen? There was no way to mount it, short of fashioning something out of Bluetack. In the end we put it on the computer in the space behind the keys and under the edge of the screen. It was small enough to fit there on our computer — but do read below to see what this does to the sound.
Cartage is where it's at with this unit. Slip into the soft-fitted pouch that comes with it and pull the draw string, and it's all ready for your suitcase. The USB cable won't fit in, though, so be careful not to leave it behind.
With the other computer speakers we've looked at it has been clear where they are intended to be located. But not this one. We've mentioned the practical issues above, but there's also the audible differences, because how this speaker sounds depends heavily on where you put it. In the physically practical space between screen and keyboard the sound was quite coloured, denoting a lumpy frequency response. Indeed, our measurements showed this to be the case.
This is inevitable when you have a speaker hard up against acoustically reflective surfaces. We re-ran the tests — including listening — with the unit carefully propped up on the edge of the screen, and it sounded much cleaner and more accurate.
Our measurements showed it to be fairly even from about 270Hz to 11,000Hz.
But subwoofer or not, the bass was very limited. Once again Edifier has gone for a fully sealed enclosure, which has an impact on the bass end. The carton says something about "an elaborately designed bass reflection port", which sounds like a misunderstood bass reflex port, but there is no such thing in this unit. Anyway, the bass acts pretty much as you'd expect it to with a sealed enclosure; it rolls off evenly at 9dB per octave from its peak at 450Hz. You're really not getting much use below about 180Hz.
But the sound that was properly reproduced was clean, balanced (in that high position) and quite undistorted.
A word on that button on the right-hand side: it is the volume control. You tap it to push up the volume, decibel by decibel. You hold it in to reduce the volume smoothly. Quite cute really.
The Edifier MP250 "Sound to Go" USB speaker unit lives up to its name. But a bit more bass would be nice, along with something to affix it to the top of the screen.