• Introduction (01:02) - Multiplier discusses what he will be covering in this series.

• What is the Sub-Bass? (03:52) - First of all, I need to establish what we mean by the words "bass" and "sub-bass". Each word refers to two different (but related) things. Sub-Bass could be the instrument, or the frequency range. I give some examples, and share how I most commonly use the words.

• Headphones or Monitors? (06:56) - When working on sub-bass/low end, what should we use to listen? Headphones or monitors? Why? I suggest some tests you need to run. They'll confirm your understanding of this, and give you a better understanding of how your headphones/DAC/etc reproduces low end. You also need to learn about the imperfections inherent in your setup.

• Pitch, Frequencies, & Harmonics (10:07) - Learn about pitch, frequencies, harmonics, and the "fundamental". This is critical for understanding the rest of this course. See the difference between a bass pitch, and the bass frequency range (answering the question: what is a sub-bass... the fundamental of the bass). And finally, what is the lowest note we can use?

• How to Create the Harmonics (10:54) - Why do we need harmonics? Explore a range of options for creating them. This includes drawing in harmonics with Serum or Operator, choosing the cycle with the harmonics we like using wavetable synthesis, as well as distortion and post-filtering. I also give a quick example of how you can layer texture over the top too.

• Layering Low Frequencies (10:16) - Explore the MOST important concept in this course, the idea that you shouldn't layer low frequencies, because they interact with each other in unhelpful ways. I illustrate the theory, and then apply this to a practical example, layering 808 tails. Then, I show how unpredictable this is. Finally, I show what this looks like in synths, "monophony".

• Mono Sub-Bass (07:09) - Should you make the sub-bass mono? Why? Spoiler, it's because lots of systems sum these frequencies to mono, and when you do, you are essentially layering the left and right channels. This "layering" is a problem (as explained previously). Also, most spectrum analyzers sum to mono too. And how do you actually make the sub-bass mono? (in Ableton, and also using a plug-in that works in other DAWs).

• Adding Reverb & Other Effects (08:36) - Is it ever OK to add time-based effects like chorus, delay or reverb to the sub-bass? If not, why? Clue, it's about layering again. I demonstrate on a practical example, where reverb caused a big issue with the sub-bass. This example is using reverb, but the logic applies to those other time-based effects (e.g. delay) too.

• When You Need to Use a High-Pass Filter (07:09) - Following on from the previous video, what do you do if you have a rumbly sub-bass, and can't go back to fix it at source? (e.g. that reverb example). You high pass filter it, and try to carefully add it back in clean. Importantly, make sure you add in the correct note, including pitch bends, and don't distort (all you need is a sine wave). I also included a trick to work out what notes and pitch bends may be in the original sound!

• High-Pass Filter Everything (03:14) - We high pass filter nearly everything, everything that doesn't creatively need the sub-bass frequencies (so usually, everything apart from the kick and bass). I show why. Spoiler, it's about layering again, and how to set the cutoff value for it.

• Clicks & How to Remove Them (08:00) - What are clicks? Why do they exist? And how do we remove them? I establish the principle behind it using audio clips, and then show how this theory applies in a synth, using ADSR envelopes. Finally, I ask the question, "in a mix, do clicks even matter?"

• Reducing Clicks Using Oscillator Phase (10:44) - This is an extension from the previous video. Learn how you can dial in oscillator "phase", to reduce clicks, without having to soften attack and release as much. Quite naturally, I first of all explain and demonstrate what oscillator "phase" actually is.

• The Problem with EQ & Low-Pass Filtering (06:31) - Let me snow how you why you shouldn't EQ or low pass filter sub-bass unnecessarily, as it'll create layering issues I bet you didn't know about! If you NEED to EQ like this, you'll at least know now what to check for, to avoid issues. EQ does more than just change the balance of frequencies, it changes frequencies in time too!

• Choosing a Clean Synth for Sine Waves (05:15) - Different synths create different sine waves. Some are cleaner than others. It's not a huge deal, but something worth knowing about and checking. Let me show you how.

• DC Offset & How to Remove It (04:31) - DC Offset. What is it? Why is it a problem? And how do we fix it? And when fixing it, what do we need to look out for?

• Checking That the Sub-Bass is Working (02:38) - It’s important to check the sub-bass in your final master, by listening through a steep low pass filter, and comparing to other tracks in your genre. Are they similar? Is the rhythm, melody, arrangement, etc. translating through just these frequencies?

• The Purpose of Sub-Bass (04:10) - What’s the purpose of sub-bass? Two ideas in this video. The first is somewhat ‘obvious’ (its weight and energy give the track more emotion/energy/etc.) The second is that the sub-bass always SUPPORTS a main purpose of the track (rhythm, emotion, aggression, etc.) It shouldn’t tell its own story, as half the listeners won’t hear it!

• How to Set Sub-Bass Level (03:35) - See how to set the level of the sub-bass. Take the guesswork out of it, and do it by eye. Analyze a range of tracks in your genre of choice, to see what the acceptable range is.

• Layering a Sub-Bass Under a Melody (03:54) - Discover how to layer a sub-bass under a melody (it's nice and easy). Also, a discussion on what part of the frequency range you want to try and get your sub-bass notes to sit in.

• Chords, Unison, & Tightening Up the Sub-Bass (14:44) - If the lowest notes of a chord are low enough to be sub-bass, we don't want them to be in "unison" (as that makes them wide and unpredictable). But what if we want the chord to sound like it's in unison? The answer is to split the chord up, and play the lowest notes in unison 1, and the higher notes in full unison. This tightens up the sub-bass, as we can carefully create it, being perfectly precise. The final example doesn't involve chords, but shares a similar spirit, just in a sound design (Serum) context.

• Tightening Up the Sub-Bass in Serum (06:46) - This final example involves a few interesting ideas. One we've seen before (removing the fundamental from an existing oscillator in Serum, then adding it back in clean and precise using a different oscillator), and the other is how we can use a bass' defining modulation, to modulate sub level too, making it sound more coherent.