Whether your preference is for software or hardware DAWs, some way of listening to your sounds and recordings is vital. Whilst the 'never mix with headphones' maxim may not be quite as true with the rise of the MP3 player, good monitor speakers are strongly recommended for the best home studios and vital for project and commercial facilities.
Whereas hi-fi audio speakers are chosen for their ability to make music sound good to the listener (by colouring the sound), monitor speakers aim (with varying degrees of success) to show recorded music as it really is, exposing any problems with the sound or mix. Make the acoustics of something sound best on high quality monitor systems and it will likely sound good played through an an audio hi-fi, MP3 player, car stereo or ghetto blaster.
Yamaha's MSP powered and unpowered monitor ranges represent the pinnacle of their studio monitor speaker line up; a highly detailed sound and near-flat frequency response have made these NS10 successors even more capable replacements. The HS range feature a richer, more 'hi-fi' like sound making them useful for additional referencing and an affordable option for home studios.