IMP Homework Podcast Episode Four Transcript

Introduction

Hello, I'm Wes Perdue from the East Bay area of San Francisco, California.

Welcome to the fourth episode of my podcast series that fulfills my weekly homework assignment for the online course from Coursera titled Introduction to Music Production.

This week we will be looking at dynamic range and ways to manipulate the dynamic range of an audio recording. I'll focus on how I use gain stages and dynamics plugins to manipulate the dynamic range of my weekly podcast. I'll also cover a few creative uses of dynamics plugins.

Over the past few weeks, I've discussed dynamics in this podcast series. In week one, I covered the signal path in my audio workstation for my weekly podcast. Last week, I took a look at the various types of dynamic effects, among other things. Please refer to these two episodes of this series if you'd like more information on these topics.

As always, definitions for all key terms can be found in the show notes at wesperdue.net.

Dynamic Range

I think we need to start with a few definitions. Dynamic range can mean subtly different things in different situations.

The first of two situations I'll address is within a medium; that is, within a container for an audio recording, or within a system that can process an audio signal. In a medium, the dynamic range is the range of amplitudes that can be detected, represented, or transmitted.

In an audio recording, dynamic range is the range of amplitudes that are contained within the recording.

Simply put, dynamic range is either the range of amplitudes that can be represented, or that were actually captured. Context usually helps determine which is being referred to.

I've included more detailed definitions in the key terms section of the show notes which can be found at wesperdue.net.

Because I work with spoken word audio regularly in the production of my weekly podcast Late Night Geekery, I've become fairly familiar with dynamic range. I need to ensure that the recording on my end isn't clipping at any gain stage so my signal remains distortion free. My colleague also gainstages carefully on his end, but his signal arrives to me processed by Skype. Skype seems to apply a noise gate, compressor, and a limiter.

So after recording, in post-production, I must use dynamics processing on my channel to bring my signal up to an equal level with my colleague's, so listening to the podcast is a pleasant experience.

This is because I'm recording my signal directly off my microphone with no affects or filters, but Skype processes my colleague's signal.

Manipulating the dynamic range of my weekly podcast

The first way I manipulate the dynamic range of my recording is by setting levels at gain stages. I set the trim on the audio interface for my microphone, and this sets the level for my recording. My colleague does the same on his end. For the recording phase, that's about it, except for the live stream mix, which is a rough version of the mix I'll do in post production.

In post production, I have the time to be a bit more thorough. I don't compress my colleague's channel; I just insert a limiter to handle any stray peaks.

On my channel, I first have a noise gate; it drops background noise to zero when I'm not talking.

Next in my channel strip I have FabFilter Volcano; it operates on my signal in two different audio domains. First, it has a high pass and low pass filter to cut out the extreme lows and highs in my signal, which helps keep my voice clear and understandable. It also is a gain stage; it boosts my signal by 5 dB so the compressor doesn't have to work so hard.

The last two plugins on my channel are a compressor and a limiter. The compressor has a low threshold of -30 dB so it can get all the nuances of my voice; it has a moderate compression ratio of 2.9:1 and a make-up gain of 15 dB so it brings up my signal quite a bit.

So, yes, both the filter and and the compressor are gain stages. The final gain stage is my fader. I usually keep it between 0 and +2 dB, adjusting it weekly to compensate for my setup that week.

The limiter on my channel is set at -2 dB with a soft knee, so transients sometimes slip through. I take care of this with a limiter on the master channel that squashes most strays. I do a final mastering pass after I bounce the mix, with a transient shaper to sharpen transients, a gentle compressor to glue the signal together, and a strong limiter to squash any peaks.

That's it for how I manipulate dynamics in my weekly podcast.

Creative uses of dynamics processors

I wanted to mention one interesting creative use of dynamics plugins I've discovered in my research. Compression can be used creatively on drum channels and even on the bass drum channel itself with extreme settings to get some very interesting results. I've been playing with Sonalksis' Uber Compressor on a bass drum coming out of a drum synth (Sonic Charge's MicroTonic), and it can do amazing things, including adding distortion and harmonics. Uber was designed to be used in an extreme manner; I recommend playing with it.

Two more compressors that can be pushed to extremes with nice results on drums are Stilwell Audio's The Rocket and Audio Damage's Rough Rider Pro. Both can really make the bass drum pump, even when applied to the drum buss. The Rocket has an interesting feature called impetus that can work with high gain compensation to create very interesting distortion.

Conclusion

So there you have it; I've given you both practical and creative examples of uses of dynamics processors, plus I walked you through the gain stages and dynamics effects in my podcast.

As I mentioned last week, there are three types of plugin effects that manipulate each of the three domains of sound: dynamics for amplitude, delay effects for propagation, and filter effects for timbre and frequency.

We will be looking at delay and filter effects next week.