Microsoft is expanding its PC hardware offerings to include a speaker system delivering sound comparable in quality to high-end home-audio systems, according to an article in the Wall Street Journal. The US software giant says its Digital Sound System 80 uses speaker technology from Philips Electronics NV and will be available this autumn for around $260. The 80-watt sound system, intended to be used with Windows 98, plays digital audio signals downloaded from the internet, CD-ROMs, audio CDs or DVDs. The system comprises two speakers and a subwoofer with a built-in digital amplifier. The digital sound is converted into analog signals in the amplifier, rather than on a PC card, reducing interference and improving sound quality, Microsoft claims.