GEAR4 is continuing its onslaught onto the portable speaker market with the announcement of the BlackBox micro, a USB-powered compact speaker with integrated SFX technology.

The smallest speaker in the BlackBox range, the micro's SFX gel base uses any flat, solid surface that it's placed on to enhance bass notes, which GEAR4 says "dramatically" improves the volume and audio quality of the speaker.

This SFX driver is accompanied by a standard driver that claims to deliver "crisp high notes".

Aimed as a travel speaker, the BlackBox micro takes audio from line-in level, so can be used with all music devices with a headphone port, and includes the 3.5mm cable necessary for linking them up.

It can be powered via USB, or from an AC charger with USB outputs with different length USB cables included. Available from August, the BlackBox micro will be £20.