At $70 (UK£54, AU$99), Sony's SRS-X11 is at the higher end of the micro wireless speaker market, which is rather crowded these days.
While you can certainly get better-sounding speakers for that price, you'll be hard-pressed to find a tiny wireless speaker that sounds as good as the SRS-X11. So, by good I mean good in the relative sense.
Weighing 7.6 ounces or 215 grams and measuring 2.4 inches (6.1 cm) by 2.4 inches (6.1 cm), the X11 is smaller than a Rubik's Cube and seems well built, with enough heft to it to make you think it's got some substance. Available in multiple color options, the speaker has a soft-to-touch finish on both the back and top of the speaker, where you'll find the power button, volume controls and an answer/end button for the built-in speakerphone, which works OK (in other words, don't expect this to perform like a business-grade speakerphone).
Additional features include and an audio input, NFC tap-to-pair technology for smartphones that support it, and the ability to join two speakers together wirelessly and create a left/right stereo pair or just double up the sound.
As I said, there are a lot tiny Bluetooth speakers out there. I like the JBL Clip Plus , Logitech X100 and Sol Republic Punk , to name a couple. From a sound standpoint, this little Sony competes well with those models and delivers better battery life -- a full 12 hours at moderate volume levels.
The speaker rates 10 watts of power, which is about double that of what these micro speakers typically claim. Like the Clip Plus and the Punk, there's enough bass to keep the speaker from sounding too thin, although you'll want to stick to more moderate volumes to prevent distortion (virtually all small Bluetooth speakers distort to some degree).
Not surprisingly, the speaker does best with acoustical material and is strongest in the midrange, producing clean sounding vocals. It did well with Laura Marling's "Strange" and Dave Matthews Band's "You & Me" and other mellower tunes. Particularly at higher volumes, it had a harder time with rock and more complicated tracks -- or anything with a lot of bass.
If you plan on cranking techno or hip-hop, this isn't the speaker for you. But for a little background music or movie watching on your tablet or laptop, the X11 makes for a decent little audio accessory, delivering louder and fuller sound than the internal speakers of most portable devices.
For a significant bump up in volume and sound quality, you're better off with Sony's larger SRS-X33 . But if portability is what you're after, this cute little cube speaker is worth considering. I like it; I just wish it cost a little closer to $50 USD.