A type of speaker cabinet where the speaker drivers are not sealed into the enclosure – there is no back, or only a partial back, to the cabinet. The sound from the speakers can emerge from both the front and the unsealed or open back of the cabinet. This broadens dispersion in the room. Open-back cabinets typically have less low-end “thump” and looser bass than closed-back or sealed cabinets. Open-back cabinets are used almost exclusively for electric guitar amplifier applications, mainly for combo amps, though there are also examples of extension speaker cabinets with open backs.