This is a simple and handy free tool for checking that your mixes are balanced in the frequency spectrum. A mix with too much bass or too much treble or perhaps even too little mid range, can distract from the music.
This provides real time display of peak, current and average frequency levels. Attach this to your master track, open it and let your song play. Adjust your EQ in real time and instantly see (and of course hear) the difference.
A spectrum analyzer can also be used to check if two instruments are competing for the same frequency space.
See the video below for a demonstration of it’s use.