A stage monitor is a rear facing speaker in an audio setup. This speaker is for the on-stage performers rather than the audience. Depending on the speaker locations, a performer may not be able to hear his instrument while playing through the main speakers. Usually this is because the performer is positioned behind those speakers. The monitor provides a speaker the performer can hear while on stage. The SRX712M is the only stage monitor in this series.
A subwoofer is a speaker that is specialized for projecting low frequency sounds. Lower pitched noises require more power than higher pitches to be recognized by the human ears. Audio setups often require a separate subwoofer to project this frequency range to the audience. The most common application for this is bass range heavy music, common in many electronic styles of music, and movie sound systems. The SRX718S and SRX728S are subwoofers.
Loudspeakers are the general speaker types used for broadcasting audio to an audience. Almost every audio application requires some form of loudspeaker. These applications include live music performance, DJ work, public address systems and movie sound systems. The SRX700 series loudspeakers are general use speakers. They are not biased toward any specific application or usage. The SRX700 series loudspeakers contain two-way and three-way models. Three-way loudspeakers contain specialized low-range (woofers), mid-range and high-range (tweeter) speakers. Two-way speakers only contain woofers and tweeters. Both types are used in the same applications. The two-way speakers have overlapping tweeter and woofer frequency ranges to cover the mid-frequency sounds. This does not provide quite the same quality as a three-way speaker, but works sufficiently for many applications. The SRX715, SRX722 and SRX725 are two-way loudspeakers. The SRX738 is the only three-way loudspeaker in the series.