Distortion - the Musical and the Problematic

Hi, I'm Lameez from Cape Town, South Africa. For this week's assignment I have chosen to explain distortion and give examples where it can be both musical and problematic. So what is distortion exactly?

Distortion turns volume variations into timbre variations.  It is related to the signal itself, as you get louder the timbre of the sound will change. Distortion occurs at the amplitude at which gear starts reacting strangely. This will happen in the non linear range of the equipment.

Musical Distortion:

Not all distortion is bad. Drive is a gain control before a distortion stage. Guitar players turn up the drive on purpose. Drive is a volume control purposefully going into distortion threshold. As the guitar player turns the drive up the sound of the guitar changes (gets brighter or grittier), and emphasizes the music dynamics or lets the instrument come through in the mix. 

Problematic Distortion:

Sometimes distortion is problematic. There are numerous places in your signal flow that you can get distortion. In other words you will need to avoid distortion at every point in your signal flow. You will want to avoid distortion if you want a clean vocal set for example. The microphone placement itself can create distortion, some examples

• If the microphone is too close the vocalist's mouth it could create microphone distortion, move it further away to eliminate distortion
• "P" and "B" sounds could create microphone distortion, using a pop filter (or moving the microphone further away) would help eliminate this

Another problematic distortion is digital distortion known as "clipping." It is important to apply careful gain staging to avoid distortion i.e. stay in the green at every point in the signal flow. In the DAW you will see clipping indicators (red light that comes up when you go over the digital maximum). Avoid these at all costs.

Displaying distortion in an oscilloscope:

1) Before distortion:

2) Entering Distortion:

You will notice the changes once entering the distortion threshold: introduction of upper partials, changing wave shape, peak level unchanged, and increase in apparent loudness

There are times you may want to use distortion musically and times you would want to avoid it completely. Be aware of it's existence. Take advantage of its uses in music production when it  is useful and know to avoid when it needs to be avoided.

Reflection:

All of this is new to me, I hope I have a good understanding of the topic. If there are any gaps in my knowledge I would like to know. I thank you for taking the time to review my assignment and look forward to any feedback.

Reference:

https://class.coursera.org/musicproduction-002/lecture/129