Pan-Pot: Stereo Image Control

A pan-pot, short for a panoramic potentiometer, is a control in audio mixing that determines how much of each source signal is sent to the left and right speakers. It is an electrical device that distributes one audio signal to two or more channels or speakers. In other words, it is a knob that you turn to move a sound left or right in a stereo mix.

Pan-pot in audio mixing

A pan-pot, short for "panoramic potentiometer", is a control in audio mixing that determines how much of each source signal is sent to the left and right speakers. In other words, it is used to position sounds in the left-to-right spectrum of a stereo image. This ability is made possible by a pan-pot or slider that allows you to individually adjust the ratio of levels between the left and right output of a stereo audio signal.

A pan-pot has an internal architecture that determines how much of a source signal is sent to the left and right buses. It splits audio signals into left and right channels, each equipped with its own discrete gain (volume) control. When centred, the law can be designed to send −3, −4.5, or −6 decibels (dB) equally to each bus. If the two output buses are later recombined into a monaural signal, then a pan law of -6 dB is desirable. If the two output buses are to remain stereo, then a law of -3 dB is desirable. A law of −4.5 dB at the centre is a compromise between the two.

A pan-pot set to zero or centre will divide the signal equally between the left and right channels. A pan-pot set completely to the left will send the signal entirely to the left channel, and vice versa. This allows the user to change the left-to-right position that a sound seems to originate from in the stereo image as perceived by the listener.

Panning is, therefore, the process of positioning sounds at particular locations in the stereo image of a mix. It creates interest, width, and a sense of space in a stereo mix by making sounds or instruments appear to come from different places in the left-right spectrum of the stereo field between two speakers. Panning can be used to create a sense of width in a mix or on individual instruments, make space for each instrument or sound in the mix, accentuate musical call and response between instruments through spread, and create interest with the use of pan automation and other creative techniques.

Pan-pot in broadcasting

In broadcasting, a pan-pot, or pan potentiometer, is a control in audio mixing that determines how much of each source signal is sent to the left and right speakers. It is a component that pans a signal across two pathways, typically adjusted using a knob or slider.

The pan-pot is a crucial tool in creating a stereo sound field, allowing engineers to position sounds left to right to create a panoramic sound effect. By adjusting the relative levels in the right and left channels, broadcasters can control the apparent position of the recorded or broadcast sound source within the stereo panorama.

For example, a broadcaster can use a pan-pot to create the effect of a sound source moving from left to right or vice versa. This is achieved by gradually decreasing the signal strength on one side while increasing it on the other.

The term "pan-pot" is a combination of panoramic and potentiometer. A potentiometer is an electronics term for a knob or dial used to adjust the level of a signal. In the context of audio mixing, the addition of "pan" refers to the panoramic effect created by adjusting the signal across two channels.

Stereo sound

True stereo involves capturing live sound using an array of microphones, which is then reproduced over multiple loudspeakers to recreate the original sound as closely as possible. Artificial stereo, on the other hand, involves reproducing a single-channel (mono) sound over multiple loudspeakers. By adjusting the relative amplitude of the signal sent to each speaker, an artificial direction can be created, giving the impression of sound coming from different directions.

The control that adjusts this relative amplitude is known as a pan-pot (short for panoramic potentiometer). It is a knob or dial that allows you to move a sound left or right in a stereo mix, creating a complete, artificial sound field when combined with other signals.

While stereo sound is commonly associated with two speakers, it is important to note that the term stereophonic also applies to systems with more than two channels or speakers, such as quadraphonic and surround sound.

Pan-pot in sound engineering

A pan-pot, short for a panoramic potentiometer, is a control in audio mixing that determines how much of each source signal is sent to the left and right speakers. It is a knob or dial that you turn to move a sound left or right in a stereo mix.

When the pan-pot is aimed to the left, the entire signal is sent to the left output or speaker. The same happens on the right when the pan-pot is aimed to the right. When the pan-pot is in the centre, there is an equal amount of signal sent to both left and right channels, creating what is called a 'phantom centre'. This makes the sound appear to be coming from a non-existent speaker in the middle of the stereo field.

Panning is a powerful tool in mixing. It can be used to create interest and excitement, or simply to create a realistic panoramic view of where sounds are coming from on a stage. For example, panning can be used to make a guitar on the left side and a hi-hat on the right, or two different synths. It can also be used to balance the thickness of a mix or spread the stereo imaging.

One technique is to pan drums based on the listener's perspective. For instance, if you were at a drum performance, you would hear the toms panned based on their physical location in relation to you. This technique can also be applied to pianos, choirs, and symphonies.

Another example is hard panning drums to one side and having some instrument on the other side playing in the same rhythm, creating a nice feel.

Pan-pot as an electrical device

A pan-pot, or panoramic potentiometer, is a control in audio mixing that determines how much of each source signal is sent to the left and right speakers. In other words, it is a knob that you turn to move a sound left or right in a stereo mix.

The term "pot" is short for potentiometer, which is an electronic term for "knob" or "dial". Panning means positioning something left to right in a stereo sound field. The verb "to pan" means to move something to a certain place in a stereo sound field.

A pan-pot enables a mono-phonic input signal to be positioned as desired between the stereo loudspeakers. When the control is in the centre position, there is no attenuation or amplification between the input and output. When the control is turned away from the centre position, the signal in one channel will be amplified 3 dB more than the other.

A pan-pot circuit diagram shows that the input impedance is set by R1 (10 kΩ). The output of the buffer is applied to stereo amplifiers IC2 and IC3. The positioning of P1, in conjunction with R3, R4, R8, and R9, in the feedback circuits of both amplifiers, means that any adjustment of the potentiometer will have opposite effects in the amplifiers.

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