Monitor speakers and headphones are critical elements of studio and live performance, mix monitoring, and assisted listening. Although studio monitor speakers are usually relied upon for tracking and mixdown in control room environments, individual artists need to be able to hear their own performance. A good headphone amp or mixer amp can really come in handy, especially when it comes to creating a tailor-made monitor mix.
Personal monitor systems, particularly the in-ear type, are gradually replacing conventional monitor loudspeaker systems, both on stage and in studios. Hardwired or wireless, IEM systems put more sound into the performer's ear while eliminating feedback and other acoustical variables.