For DC motors, too low a frequency can cause audible whining and jerky torque, while using a frequency in the 2–20 kHz range keeps operation smoother and moves the noise above the human hearing range. Going too high can reduce efficiency due to increased switching losses.

For LEDs, low frequencies below ~100 Hz cause visible flicker, which is unpleasant and can be noticeable on cameras as well. Frequencies in the 200–500 Hz range reduce flicker significantly, but for professional lighting or display applications, 1 kHz and above is generally preferred to ensure flicker-free performance.