This document discusses distortion in audio recording and its musical and problematic uses. It defines distortion as any change to a waveform, especially those caused by non-linear devices like tube amps. Harmonic distortion adds new harmonics and can sound good if they are musically related, while odd harmonic distortion tends to sound harsh. Distortion becomes problematic when signal levels are too high and parts of the waveform are lost, resulting in raspy sounds. Factors that can cause problematic distortion include microphones placed too close to loud sounds, equipment volume controls being turned up too high, speakers being pushed beyond their limits, and faulty equipment.

1. Distortion
Musical or Problematic?

2. Objectives
• Understanding the definition of Distortion
• Ways distortion can be musical
• Ways distortion can be problematic
This is Subrina, I chose this particular topic as it is so
often misunderstood. When I looked up the word
distortion, I found 4 different definitions. I wanted to
understand what distortion means in the context of
signal flow in audio/digital recording.

3. What is distortion?
• The term 'distortion' describes any change made to
a waveform: even a simple change to the amplitude is
technically a form of distortion, as is EQ, which is, in essence,
an amplitude change to specific frequencies.
• More commonly, though, we intend it to mean something
that happens when audio passes through a non-linear device,
like a saturating tube amp or a clipping preamp. In both cases,
the main function is to change the amplitude, but the
distortion process introduces new harmonics that are
musically related to the original signal in some way.
• Obvious distortion is something to be avoided if you want to
make accurate recordings of acoustic instruments, but it has
many creative uses in popular music .

4. Musical - Distortion
So how can we use distortion creatively?
• Harmonic distortion
• Speakers
• More does not mean great

5. Musical-Distortion
• Harmonic distortion
The harmonic content of a signal gives a sound its timbre (this is
what makes a flute sound different from a clarinet). Harmonic
distortion is the introduction of extra harmonics that are
musically related to those already present, resulting in a change
in timbre. Even order harmonic distortion tends to sound
musically sympathetic, smooth, and bright in a constructive way.
Many simple valve-based circuits (including most using triodes)
tend to generate mostly even-order harmonic distortion.
Odd order harmonic distortion (the predominant type
produced by analogue tape, for example) tends to sound rough
or harsh, gritty or edgy, and is often associated with added
'richness‘ and 'depth'.

6. Musical - Distortion
• Harmonic Distortion
The higher harmonic components created by analogue distortion
tend to sound gritty and fairly unmusical — so rolling off the high
end can produce more ear-friendly results. In guitar amps this
happens naturally, as their loudspeakers tend to roll off quite
quickly above 4kHz. The best way to describe this; without the
speaker, the top end of a guitar through a fuzzbox sounds like
a wasp in a paper cup!

7. Musical - Distortion
• Harmonic Distortion
One way to add very organic-sounding distortion to a track
is to feed the recorded sound out to a guitar amplifier and
then mic it up, returning the miked signal to the mix. This
technique is often used for 're-amping' guitar and bass
Parts that were initially recorded via a DI — but it can
also produce interesting results on drums, synths, and even
the voice.

8. Musical - Distortion
• Speakers
Whether it's a plug-in, or a hardware device such as
a Line 6 Pod, an emulation of a guitar speaker can work just
as well as a real speaker. Try using one in place of
a low-pass filter to tame high frequencies. As with
re-amping, you're not limited to guitar signals: try it with
distorted synths, organs or electric pianos. In fact, this
approach can be more flexible than re-amping, as most
modelling plug-ins give you a choice of speaker cabinet
types — so try them all and pick what sounds best to you
for your part.

9. Musical - Distortion
• More does not mean Great
When recording, be cautious: avoid adding more
distortion than you will eventually need. You can always
add more during mixing if you need to, but there are
very few practical ways to reduce distortion in
a recorded piece of audio. If you're uncertain, it pays to
play safe and use a splitter or A/B box to record an
undistorted, 'dry' version of the input signal alongside
the distorted one.

10. Problematic - Distortion
• Distortion can be problematic; how so?
Unwanted distortion is caused by a signal which
is "too strong". If an audio signal level is too high
for a particular component to cope with, then
parts of the signal will be lost. This results in the
rasping distorted sound.

11. Problematic - Distortion
Distortion can occur at any point in the signal
flow. Factors to take into consideration:-
• Placement of microphone
Is the distortion coming from the microphone
due to loud noise being too close to the mic? If
yes, then it is crucial to move the microphone
away from the source of noise or use a pop
filter also known as pop shield .

12. Problematic - Distortion
• “Peak” or “Clip” lights
Look our for “peak” or “clip” lights on any of the
equipment being used as they serve as warning
signs. Stay in the green at every point in the
signal flow.
• Volume or Gain Controls
If volume or gain controls are turned up high,
this can cause distortion.

13. Problematic - Distortion
• Speakers
If an amplifier is pushing the speakers beyond
their designed limits, the distortion becomes
permanent. This type of distortion is the worst form
also known as “clipping”
• Faulty Equipment
Utilizing faulty equipment can also cause
distortion. Therefore, check to see what needs
to be done to maintain equipment.

14. Thank you!
I hope you have found my presentation easy to
comprehend and that you have learnt a thing or
two you did not know previously.