Mono vs Stereo Audio in Music Production – Explained

Mono vs Stereo Audio in Music Production - Explained

Starting in the music production and audio engineering business could be quite an anxious endeavor. First, you’d have to try not to lose your mind in choosing the right equipment amongst the shocking variety of audio interfaces and microphones. As well as what to choose for recording: mono vs stereo? Don’t even get us started on acoustic room treatment. Then you would spend some time actually learning the craft. That’s a whole another story.

What is it all about?

Sure, nobody said that you have to get a degree in audio engineering or applied physics, for that matter. But as far as things go, the more you know, the better results you get. A question might occur before you could actually start. How to record the material, since there are quite a few options available?

Not to worry, we’re here to help. Thinking about how to record the material better – in mono vs stereo? Or do you do both at the same time? Let’s find out.

How we hear things

If you’re not into nerdy stuff, skip this part. The rest of us should know that audio production at its core is based on our ability to localize a sound source and to measure the distance to it. Human auditory perception, or hearing in simpler words, is a system that can register mechanical waves, which are called vibrations, and interpret them as sensory information.

Vibrations are collected through the outer ear and sent directly to the brain’s temporal lobe, where it’s strictly up to you what to do with the information received. The outer ear consists of two ears; thanks to that, your temporal lobe can allocate where the source of the signal is relative to your position. It does it by measuring the time difference between two ears to receive a sound.

If the sound source is located slightly ahead on your right, your left ear will register vibration a couple of milliseconds later than your right ear and vice versa. If the signal is right in front of you or behind, both of your ears will register it at the same time. You measure the distance to the sound source by registering the perceived loudness of it, and because we don’t want to bore you even more, we won’t go any further than that.

Monophonic signals

Since we know that a healthy human being hears exclusively in stereo, why do we even need mono? The answer to that question is in the definition of mono. According to Wikipedia, monaural (monophonic sound reproduction) is sound perceived and heard from a single position. Usually, in audio production, that position would be right in front of the listener.

Due to technological limitations in the past, mono was the only option on master stages. Before 1958 the most used sound reproducing equipment were gramophone records and reel-to-reel tape machines, which both were monophonic. Since then, almost all consumer sound equipment has become stereophonic. TV stations and smartphone loudspeakers were the last to give in.

Despite those facts, mono is widely used to this day. In fact, this is the most common recording technique. The thing is that almost all microphones that you can get your hands on are monophonic in their nature. Unless you are in possession of a very expensive binaural mic, but we will get to this part later. So, basically, using only one mic gives you no choice but to record in mono.

To this day, monophonic recordings are widely used in radio broadcasting, precisely in talk shows and interviews. Some filmmakers, such as Woody Allen, prefer to mix their movies in mono. But that’s more of an artistic decision to get more of a vintage feel to their art. Same as audio engineers using vintage analog equipment, such as tape machines and compressors, in their production. Also, supermarkets’ notification systems are all in mono because why would they be in stereo, right?

Stereophonic signals

Stereophonic sounds are made of two independent signals in separate channels. It’s intended to emulate multidirectional sound sources as we would hear them as if they occurred naturally. Stereo is the most widely used sound reproduction system apart from a few surround systems that have five channels or more and are mostly used in movie and home theaters.

Despite that most of the most reproduced sound you hear is in stereo, it is not a true stereo per se. It is rather what is called a double mono. The idea is if you have one mic, you can record only one mono signal. If you have two of those, you can, in fact, record two mono signals. Those signals could then be sent to a separate channel each, thus giving you an illusion of a wholesome stereo signal, which is how most material is recorded these days.

Still, the problem with recording double mono is that you cannot do this with any two random mics. Due to the different frequency and dynamic responses that at least wouldn’t sound natural, at most, you’ll get some unpleasant phasing issues. Even using the same brand and model mics likely won’t give you much benefit. To avoid such issues, you need to get your hands on a set of stereo paired microphones. Those are tuned at the factory so that they would have as similar frequency and dynamic response as possible.

Recording techniques

It gets rather simple from here – your recording techniques are very much dependent on your artistic vision. If you want a more refined and focused sound, record it in mono. But if your goal is to make something sound with depth and a sense of space – stereo is a way to go. Despite everything, below you can find several ways of using mono vs stereo in music production.

The most obvious example would be the recording of the lead vocal. Since usually, you want the vocal to be a focal point of the mix, you will record it in mono and place it dead center. On the contrary, background vocals are usually intended to add weight to the lead performance. It would be a better solution to record it with the stereo pair of mics and pan it left and right in the mix.

Generally, all monophonic instruments such as vocals, guitars, strings, solo woodwinds, are recorded in mono with some exceptions. There is a technique that is called double tracking, which is widely used in music production. You record a musician playing his part in one mono track, and then you make him play the same part again and record it on another mono track, then you pan those two recordings right and left in the mix. Slight discrepancies in the performance will give you a sense of stereo depth. This technique is most prominently used in heavy metal and rock music production.

If the instrument is polyphonic, you generally would be better off recording it in stereo. Instruments such as pianos, drums, and orchestras are usually recorded in stereo. More often than not, with different mics placed on different positions to get more detailed and rich sound. Recording of acoustic guitars, which are monophonic, on the other hand, greatly depends on the performance. The recording of a solo part should be in mono, and strumming is better to be recorded in stereo to get spacier and filling sound.

Binaural signals

We already know that what we call stereo isn’t a true stereo, but there is one more slight problem. In the human hearing position of the ears is very important to figure out the sound placement. Believe it or not, your head plays an even more prominent role – it’s actually obstructing the sound. This phenomenon is called “head shadow”, and there are special microphones that factor this phenomenon. Usually, those microphones look like a human head with stereo mics placed where ears would be.

Those mics are designed to emulate human hearing as accurately as possible. Binaural recordings are usually used in field recordings for cinema production. But more often than not, those microphones are used in ASMR production. ASMR stands for an auto sensory meridian response, which is a psychoacoustic phenomenon that causes a tingling sensation while listening to a binaural recording. Despite ASMR being trendy nowadays, it gives little to no benefit of using binaural mics in music production.

Conclusion

In general, opposing mono vs stereo in music production would not be that beneficial to you. To record in mono vs stereo should depend on your artistic choices and the general goal of music production. Most of the time, it is better to set a goal before doing something and to establish steps that will lead you to that goal. That being said, a little experimentation would not hurt anyone either. The vital thing to remember is that instead of retracing the steps that others have done, you should be focused on having a desire to invent something new yourself.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.