What Happens If You Plug A Mono Plug Into A Stereo Jack?

In audio production we work with different equipment such as mics, cables and all sorts of other gear.

In this post I’ll discuss What happens when you plug a mono plug into a stereo jack…

But before we get into that, let’s get a working understanding of both.

In audio engineering we use a stereo plug to connect two different sources of sound like one speaker and one amplifier source.

Mono on the other hand refers to the unit that connects to the stereo and not both.

Now that we have that out of the way….

What happens if you plug a mono plug into a stereo jack?

Plugging a stereo jack into a mono plug basically shorts your right channel to ground at the source, which would in turn give you audio in the left channel only.

While plugging a mono jack into a stereo socket will allow you to hear your left channel only because your right channel will be grounded.

Mono is usually designed in such a way that it can only handle one signal that is connected to it.

The reason why these unit types can only handle one source is because they use transistors to be able to control the volume of the signal that is fed into them.

Therefore, When you plug a stereo headphone into a mono jack you will end up with sound only on one side. A mono plug into a stereo jack will produce only the left channel from the jack into the headphones.


Mono sound reproduction  is intended to be heard as if it were emanating from one position. This position is what is sometimes referred to as the centre.

This is basically different from stereo sound which uses two separate audio channels to reproduce sound from two different signal sources like two microphones on the right and left side, which is often reproduced with two separate loudspeakers to give a sense of the direction of sound sources.

In mono, only one speaker is necessary, but, when you play mono through multiple speakers or headphones… what you’ll essentially be getting are identical signals being fed to each

speaker, resulting in the perception of one-channel sound “imaging” in one sonic space between the speakers (provided that the speakers are set up in a proper symmetrical critical-listening placement).

Mono recordings, like stereo ones, typically use multiple microphones that are fed into multiple channels on a recording console, but each channel is simply “panned” to the center.

In the final stage, the various center-panned signal paths are mixed down to two identical tracks, which, because they are identical, are perceived upon playback as representing a single unified signal at a single place in the soundstage.

In some cases, multitrack sources are mixed to a one-track tape, to become one centred signal.

In the mastering stage, particularly in the days of mono records, the one- or two-track mono master tape was transferred to a one-track lathe used in order to produce a master disc intended to be used in the pressing of a monophonic record.

Today, however, mono recordings are usually mastered with some nuance to be played on stereo and multi-track formats.

However, they retain their center-panned mono characteristics.


Stereophonic  more commonly calledstereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective.

For example, surround sound uses the concept of stereo to give the listener a 3D audio perspective.

In normal 2 audio channel set ups however, this is usually achieved by using two independent audio channels through a configuration of two speakers or stereo headphones in such a way as to create the impression of sound heard from various directions, like natural hearing.

Stereo sound systems can be divided into two types:

The first is “true” or “natural” stereo in which a live sound is captured, with all of its natural nauance such as reverberation or ambience present, by using an array of  microphones.

The signal is then reproduced over multiple loudspeakers to recreate, the live sound as closely as possible.

The second type of stereo is the “artificial” or “pan-pot” stereo, in which a single-channel (mono) sound is reproduced over multiple speakers.

This is done by varying the relative amplitude of the signal sent to each speaker.

The control which is used to vary this relative amplitude of the signal is known as a “pan-pot” (panoramic potentiometer).

By combining various “pan-potted” mono signals together, a complete, yet entirely artificial, sound field can be created. Therefore mimicking natural stereo.

But the fact is, In technical usage, true stereo means sound recording and sound reproduction that uses stereo-graphic projection to encode the relative positions of objects and events recorded.