A common question novice musicians and recording artists may have involves understanding mono vs stereo when it comes to recording. There are so many terms and factors to understand (EQs, compression, tracks, condenser, busses, etc.) that the most basic things can easily be overlooked.
Whether it’s better to record in mono or stereo comes down to numerous factors. The type of instrument, the number of microphones normally used, and the final aim (goal) for any particular track are all considerations that need to be made.
Why a Seemingly Elusive Answer?
In truth, this answer is not elusive. It is simply a question for which there are no right or wrong answers. There are going to be times when recording in stereo is optimal. There will also be times when recording in mono is optimal. It’s not always about how live performance mics are usually set up or even the desired effect on the track in mixdown that determines this answer.
First, though, it’s essential to understand the fundamental differences between mono and stereo in a recording.
A Simple Definition of Mono vs Stereo
When there are two tracks, even if they are identical, then they can be spread out in the mix (called panning). This creates what is most commonly referred to as a ‘stereo’ sound or effect. The sound will appear to be moving evenly to both ears or speakers, but not giving the sense of coming from a center point.
Mono is one track and can either be sent to the left speaker, the right speaker or left center-position. The difference with mono is there’s only one option. With stereo recording, a person can send one side of the stereo track 50 percent to the left speaker and the other side only 30 percent to the right speaker. This can create subtle dynamics that, when factored into the overall mix, can have a powerful effect.
A more simplified explanation of mono vs stereo is this:
Mono = one audio source.
Stereo = two audio sources.
What Tracks Should Be Stereo?
This is the most important question in determining whether you should be recording in mono or stereo. What instruments are ideal for this?
If an instrument is generally recorded with one microphone, such as the kick drum on a percussion set, then this would be best suited for a mono track. If a keyboard sends out a stereo signal (which almost all of them do), it would be ideal to record as a stereo track.
Some guitarists have stacks of amps with two speakers. The effects they utilize to get their sound may produce a stereo effect, moving sounds from one speaker to the next, for example. If that’s the case, then two microphones would be ideal. One would be set up at one speaker and the other mic at the distant speaker. This would be a stereo track.
However, if the guitarist only has one amp and one speaker, then only one microphone would be needed. There are those who do set up two microphones to record electric guitar tracks when only one speaker is used, but this won’t produce the level of result that person has in mind initially.
Some common instruments, or tracks, that would benefit from stereo recording would including overhead drum mics (usually two are used, one on the left and one on the right), acoustic guitar recording, keyboards, and other special instruments or digital effects that produce stereo outputs.
Keep in mind that for electric guitar racks, recording stereo from the source (the effects rack) is not optimal because that utilizes only solid-state technology and completely negates the warmth that tubes create through the effect of the speakers (assuming the guitarist used a tube amp, which produces a far better sound for final mixing).
Instruments that are most optimal for mono recording are vocals, each drum head and cymbal (a different recording track should be used for every drum and cymbal, which can complicate things if there are limited mics, lines, and tracks), bass guitar sounds, and other mono signal devices.
Doubling of Tracks
When a novice begins recording, they often run into some questions and problems. One of those is figuring out the best way to create a ‘fuller’ sound, such as for vocals. Because most recording systems are now on computers rather than analog tape decks, for example, it’s easy to simply ‘double’ a track and create an artificial stereo recording.
There are a couple of fundamental problems with this mentality. First, the track isn’t stereo. It’s two mono tracks now doubled, so it’s basically only increasing the decibel (dB) level of the recording. Yes, those two tracks can be split out, but the effect is minimal; it still won’t produce a true stereo effect.
Why is that? Essentially, the reason we hear in stereo is that the one ear is hearing sound at a different timing than the other ear, and vice versa. For example, if you stand outside and listen as a car approaches if it’s coming from the right of you, your right ear is capturing the sound ever-so-slightly sooner than your left. When it passes, your left ear will then be hearing that sound first.
This contrast is what creates true dynamic stereo sound.
So, if you’re listening to identical, copied tracks, even though they’re panned apart right and left, there’s no genuine stereo effect happening.
How to Create a Stereo Sound from a Mono Instrument
One way to create stereo sound from a mono instrument is artificial. The other is genuine. For final mixing and to get the best possible finished product, genuine is always the way to go.
To do this, record the same exact track with the instrument you want in stereo a second time. If it’s a vocal track, have the singer record the same track that needs to be in stereo. If it’s a guitar track, require the guitarist to record the same track you want to be doubled.
This may require several takes, depending on the caliber of musician or artist laying down the tracks and the relative complexity of the track. However, even though they may sing or play the track the same, there are going to be many subtle differences that, when mixed properly, bring forth the full desired effect.
To artificially generate stereo from a mono recording, double the track, but off-center it. This means when you open the track on the computer, the wavelengths will be positioned in the same timeframe as the original (as it should, as an exact copy). However, take the copied track and drag it to a minuscule degree off-center.
This technique will generate a slight auditory variation and a false sense of stereo. It’s more of a delay effect now.
Ultimately, the most genuine and ‘warmest’ stereo sound from mono will always come by recording an identical track rather than copying.
Effects for Mono Tracks
Creating stereo effects on mono tracks is possible. This utilizes routing the mono signal to stereo effects processors (such as reverb, chorus, delays, EQs, etc.) using auxiliary sends. For this, it requires a decent mixing console or computer-based recording program.
Keep in mind, though, that the effect will be what’s brought back into the mix in stereo; the recording is still mono, and it’s essentially the same as a copied or duplicated track and will not have the kind of full sound one may desire for the final mix in stereo.