In this Quicktip, we will look at how to achieve an audio effect where it sounds as if someone is talking through a phone or through a tiny speaker.

Below is a clip in the timeline where a flight instructor is talking on a headset to a student pilot in the seat in front of him. If you were to play this clip, it would sound very clean - almost as if it was recorded on a sound stage or something.

1. To achieve the “phone” effect, we need to apply an audio effect called a “band pass filter”. Make sure you’re your playhead is parked anywhere over the clip, then from the effects menu, choose Audio Filters>Final Cut Pro>Band Pass Filter.

2. Double click the clip to load it into the Viewer, then click the filters tab.

The Band Pass filter is one of many “equalizing” filters that allow you to increase or decrease the strengh of a given frequency range or band. Since phones and speakers do not reproduce high and low frequencies, you can use this filter to selectively cut the frequencies at the high and low end to simulate this effect.

The slider called “frequency” allows you to “dial in” the frequencies to be affected. Human speach falls between 250 and 4000 Hz. I’ve found that a good starting point on the slider is around 2000 Hz.

The slider called “Q” allows you to widen or narrow the range of frequencies affected. A lower Q value accentuates the voice, while a higher Q value screens out more of the frequencies above and below your target frequency. In order to simulate a person talking through a phone speaker, you will want the Q value on the high side. I’ve found that a Q value of around 15 works well.

Oh, and one more thing. Because you’ve restricted your audio output to specific bands, you will notice your overall audio volume drop considerably. You will need to compensate for this by increasing the volume level of the clip.