Which is better really depends on the type of music you listen to and the volume required. Sealed enclosures make a more tight punchy, accurate sound. They are supposed to be better for pop, light rock, jazz,country etc..Ported enclosures work by using a vent to give better low bass response. They produce a looser, deeper sound and are louder when compared to a sealed box using the same amp. Ported enclosures are good for rap and hard rock. Ported boxes will also be bigger as they require more cubic litres.