- In this video, I'm going to explain the difference between
mono and stereo sound and provide some audio example
comparisons along the way. (upbeat music) Hello. My name's Charles Hoffman. If you're interested in
music production tutorials and gear roundups, consider subscribing to the Black Ghost Audio YouTube channel. The difference between monophonic
and stereophonic sound, or mono and stereo sound,
is the number of channels used to record and play back audio. Mono signals can be
recorded and played back using a single audio channel, while stereo signals need to be recorded and played back using two audio channels. As a listener, the most noticeable difference
is that stereo sounds are capable of producing
the perception of width, whereas mono sounds are not. To hear the difference
between mono and stereo sound, you'll need to listen to this
video using a pair of earbuds, headphones, or studio monitors. If you choose to use studio monitors, your speakers should be angled
about 45 degrees toward you. Make sure that you position
the back of your head in an equilateral triangle
with the speakers. This will ensure that you
perceive stereo sound as intended. I've included a few affiliate links to products mentioned in this video in the description down below. If you make a purchase after
clicking one of these links, Black Ghost Audio will earn a bit of money to make more helpful
content just like this. Playback systems that
make use of two speakers, are referred to as stereo systems. Stereo audio files such as
stereo MP3 and WAV files, contain left channel and
right channel information that tell the left and right speaker when to push and pull air. If you've ever looked at the waveform of a studio audio file, within a digital audio workstation, you've likely noticed that
there're two waveforms a part of the file. Each of waveform represents
a single channel of audio. When looking at a mono audio file, you'll notice that it only
contains a single audio channel. Stereo systems are capable of creating the impression of sound
source localization. Sound source localization
refers to the human ability to locate the position of a
sound source within a space. For example, if you hear a dog barking, it's pretty easy to determine the direction
the sound is coming from, and how far away the sound source is. In this example, the
sound source is the dog. Most people should be
able to localize sounds with decent accuracy even
with their eyes closed. It makes sense to assume
that you'd perceive the sound produced by stereo system to come from
two distinct sound sources; the left and right speaker. In some situations, you will perceive sound coming
from two different directions but this isn't always the case. The human brain is easy to trick because it uses simple
concepts to localize sounds. These concepts include time differences between sounds reaching
the left and right ear, sound wave frequencies, sound wave pressure levels, dynamic range, and reverberation amount. Stereo systems exploit
how gullible your brain is to create the impression of
sound source localization between the system's
left and right speaker. The sound source closer to your left ear will produce sound waves
that reach your left ear before reaching your right ear. Even though these timing
differences are small, they help your brain localize the sound. When you mirror this process
using a second speaker, and feed both speakers the same signal, each ear hears the exact same thing coming from two different directions, but your brain doesn't perceive
two distinct sound sources. Instead of perceiving two sounds, coming from different directions, you'll perceive a single
sound located in front of you. This is referred to as a
"phantom mono sound source," because the true sound sources,
which are the speakers, are positioned out to the sides. In nature, when a sound source produces
a sound in front of you, the sound waves it produces reach your left ear and right
ear at exactly the same time. As differences are introduced
to one of the signals, the sound they produce
will be perceived as wider, but still centered. When enough variation has been introduced, the listener's echo threshold is broken, and the phantom mono sound source will tear apart into two distinct sounds, coming from two different directions. In the following audio example, a gradually growing delay has been added to the right channel. ♪ Centuries of feeling down, ♪ ♪ But today I ha haa I, ♪ ♪ When you're lying on the ground, ♪ ♪ All you do is a ha haaa. ♪ - Width is just one of
the three dimensions you're capable of perceiving through the use of a stereo system. The other dimensions
include height and depth. All together, these three
dimensions form a 3D space known as a "stereo field." David Gibson's book, The Art of Mixing, does a great job of
visualizing stereo imaging. I've linked to a video in
the description down below, that demonstrates how track
elements have been positioned within the stereo field
of different songs, using visual elements
from The Art of Mixing. Frequency dictates the height
at which you perceive sound within a stereo field. High-frequency sounds localize themselves above
low-frequency sounds. For example, the hi-hats in a song will sound as though they're positioned above the bass guitar. Depth is affected by a
sound's relative level, dynamic range, and reverberation amount. Sounds with a weak level
and less dynamic range, tend to appear toward the
back of the stereo field, and so do sounds
containing lots of reverb. Mono playback systems use one speaker and can only produce a
two-dimensional image consisting of height and depth. Two speakers spaced
apart from one another, are required to create
the perception of width. Many cellphones now come with
two speakers built into them and boast the ability
to produce stereo sound. It's true they can do this, but since cellphones
aren't generally that big, the built-in speakers
are never that far apart, so the stereo image they
produce will be quite narrow. When you record a sound source
using a single microphone, you capture a single channel of audio. Playing back a mono recording like this can be achieved using a single speaker, or pair of speakers. Mono sounds that are played back via the use of stereo system, will play back in dual mono. The single channel of audio is duplicated and sent to both the
left and right speaker. To capture true stereo recordings, you need to use two microphones. When you process a stereo recording, you'll need to pan one of the microphone
recordings to the left, and the other to the right. The following audio example contains a back-to-back comparison
of a mono guitar recording and stereo guitar recording. (narrow mono sound guitar music) (wide stereo sound guitar music) (narrow mono sound guitar music) (wide stereo sound guitar music) The stereo microphone technique being used is called the X-Y technique and it tends to produce a
moderately wide stereo image that is also mono compatible. You can achieve an even wider stereo image by angling the microphones
outward further, or by using different acoustic
guitar recording techniques. Many handheld recorders provide the ability to record in stereo, capturing sound using a pair
of built-in microphones. Information captured
by the left microphone is saved to the left channel
of the saved audio file, while information captured
by the right microphone is saved to the right channel. For example, the Zoom H4n
Pro contains two microphones, and allows you to record in stereo. If you liked this video, make sure to hit that Subscribe button, and also follow us on Facebook, Twitter, and Instagram @blackghostaudio. In the comment section down below you'll find a link to enter our giveaways. We give away tons of music
production software and hardware, so it's definitely something
you should check out. Thanks for watching, and I'll see you next time. ♪ Dark prince rising ♪ (upbeat music)
