An abbreviation for Inches Per Second. IPS is normally used to describe tape speed in tape recording machines. A typical cassette recorder operates at 1 7/8 IPS, where reel to reel machines can range from 1/ 7/8 all the way up to 30 IPS. Faster speeds will sound better (all other things being equal) and have less noise, but can get expensive. A standard reel of 2-inch tape costs well over $100, and at 30 IPS will only hold about 15 minutes of music.