Until recent times, a true Hi-Fi system included just two stereo speakers. However, with the huge increase in sales of smaller speakers - possibly due the increase in inner-city apartment living - there has been a corresponding increase in subwoofer sales. Just a few years ago connecting a sub to an integrated Stereo amp was difficult. Not so today. There is number of Stereo amplifiers and Network receivers that have a subwoofer output. Our 2.1 Speaker systems are perfect where space is limited but performance is key.