monitor speakers: In the actual sense of the term, a type of reference loudspeaker that is used to monitor the original signal or to objectively compare a playback signal with the source signal.
Monitor loudspeakers are often specific high-quality models from specific manufacturers that are part of the standard equipment in recording studios and therefore allow a certain degree of comparison. Because monitor speakers mostly Bookshelf speakers are, small and compact consumer loudspeakers are often referred to as monitor loudspeakers in the trade.