Just bought the A4TECH Headset + 2.1 Speakers HSB-500U. So far, it is working working well. It is a USB-Audio device but despite this, the volume range is good.
There was no need for drivers on XP. It ran without any problems.
The control unit has a 3.5mm input jack which accepts the subwoofer, and I have found it can be used to plug in another speaker.
PHP1,050 cash at PC express.