: Likely a custom edit or test tone. The "100" may signify a 100Hz test frequency or a "Fluidity 100%" quality preset.
: The "4558" may refer to an audio track specifically edited (edit 4558) to test the frequency response or distortion levels of an amplifier board using that specific IC. Download fluidity 100 edit 4558 mp3
: Associated with the RC4558 Op-Amp , commonly used to manage gain and low-frequency signals in bass amplifiers. : Likely a custom edit or test tone
