The PQ-50 has 4 bands labelled Low, Low-Mid, High-Mid and High. Each band can be adjusted as much as +/- 20dB over a bandwidth ranging from 20Hz to 20KHz. For the high and Low bands there are two EQ curves available. Peaking EQ is for accurate boost or cut at a specific frequency range. Shelving EQ is for overall tonal contouring. Harmonic distortion is down at 0.03% while the residual noise level is down at -97dBm. Through a switch at the back the input signal can be switched between -10dBm (instruments) or +4dBm (line level).