Vortex Sound Research

So far ive bought a 1/4” TS to BNC cable. What im having a hard time navigating through are which scopes i even would need, because i only need to be able to have something that can measure down to 20hz as per calibration instructions i saw online. Seems like alot of scopes have many dials and controls and sometimes not so obvious and simple displays of the current input frequency.

This all is because my tuner app doesn’t reliably read much past 40-50hz