What is 6ohm in amps?

Ohms is a measurement of resistance between the amp and speakers. Most home audio is 8 ohm, if you run 4 or 6 ohm speakers you cut resistance down and get more power out of the amp. Say your stereo is 100X2 @ 8ohm, if you use 4 ohm speakers you should get 50% more power BUT the amp is working twice as hard and can burn up.