Creating A Filter Pan Effect

David Mellor:  Open quote, the more constraints one imposes, the more one frees oneself of the chains that shackle the spirit, close quote. That's what Igor Stravinsky said in 1942. Clearly, he didn't have in mind that today I'm going to be demonstrating his idea in Digital Audio Workstation software or in this Sound On Sound podcast. But I think it's true to say that the wiser the words, the wider the application. I'm David Mellor and today I'm going to explore a simple effect made from first principles. It's just one simple example of what you can do without fancy plug-ins. Let's dive in and see what we can achieve. So I'm going to make some pan effects using only the standard features of my DAW and okay, one extra plug-in. Channeling the spirit of Stravinsky, clearly, some door uses will have fewer facilities and plug-ins available than others, but those of us with more meagerly specified setups will surely be pleased to have our creative spirits unshackled. Anyway my point is going to be not just to drop in a plug-in and dial up a preset, it's about constructing effects from scratch and I'm going to give you a focused example. Just to expand on this a bit further, not only are you freeing yourself from your chains, you're also creating something that other musicians and producers don't have. At a certain level, everyone has the same plug-ins and the same presets, which of course sound the same, but if you do it for yourself you'll create something that no one else has, at least not just at the mere click of a mouse. To put a benchmark on resources I'm using Pro Tools and I'm kind of imagining the Pro Tools of an earlier era when the plug-in compliment was, well, all that you need, but not much that you could call fancy. And other than I mentioned one extra plug-in earlier, I'm going to try to stick to functions you'd find in any DAW. So what do we need for this kind of fun? Well, I'm playing with pan effects, so I'll have to demonstrate standard pan, but after that I'll be using automation and EQ, just that. I say EQ, but I'll be using an EQ plug-in with filters and I'll be using only the filters for this demonstration. It's the Slate Digital Infinity EQ but there are other EQs out there that will do the job just as well, so don't think you need specifically that. Now, I'm going to need some music. If I'm being realistic, these kinds of effects will probably find their best use in EDM music, electronic dance music just to be sure. Now, I don't mind a sandstorm every now and then, but EDM is by no means my skill, so I'll be using tracks of my own that I like to call music, but some listeners have had their doubts. Anyway, this is about the effects and hopefully you'll be able to imagine how they'd sound with your own music, whatever your genre. I'll mix the music up a bit to avoid ear fatigue. For completeness, I need to demonstrate plain old pan. So here's a mono clip starting panned center, then all the way to the left, all the way to the right and back to center. You knew that, of course you knew that. But one thing that I've found causes confusion is the meaning of the word pan. I don't need to consult Susie Dent on this, although I'm sure her comments will be very wise. But what some people will interpret from pan is setting the pan controls of the instruments and vocals of a mix, then leaving them there, or maybe some fine tuning but again leaving them where they are in the final bounce. So panning is something that's decided on then left alone. But for others, panning means actually moving the pan control using automation. For many genres of music this will do nothing other than make things worse, but it's a standard tool of the trade in EDM to be used when a producer feels like it and of course, in any kind of experimental music, you'll use any tool in the toolbox. Then there are Jimi Hendrix soundalike acts. I think the meaning of pan should be obvious from the context in my examples, but maybe I'll say static pan, when the pan control is set and left alone. Let's try another example this time with static pan. There, I said it. This time I have a stereo track. I'll start with the track as created, then statically panned two thirds left and two thirds right, then one third left and right, then entirely mono. You'll hear the change after every two bars. Okay, you knew all that already, but it's best to set some baselines I think. What I'm going to do now will be completely out of the cricket ground in comparison. Firstly, I'll play you some music playing without any pan automation and no plug-ins. It is, shall we say, a little more experimental. The static pans are fixed, hard, left and hard right. Don't worry, it's only 11 seconds of your life. I'm using Pro Tools here and of course this process will work in any DAW. What I've done though is separate my original stereo tracks into left and right mono tracks for all of the following examples. Pro Tools makes that easy, some other DAWs, as I've found, make it difficult. I don't know about all of the other 32 notable DAWs as listed on Wikipedia, which you may or you may not have to look up on how to separate a stereo track into left and right mono. Back to the audio, just the plain music as originally produced, 11 seconds. You might have noticed that there's some panning that's intrinsic to the synth presets I used. It should add to the fun. Now completely gratuitously, though not particularly related to the music, I'm going to add a pan effect, what I'd like to think of as a creative pan effect. Here it is. Well, you can't do that with plain old pan controls. What I've done is insert an EQ plug-in in the left channel and I'm using only the high-pass filter. I set it to its lowest value so that only frequencies above 10Hz get through. Not that there's anything below 10Hz, but I like to be correct. I've set the slope to the maximum I have, which is 120dB per octave. Now, this is why I'm using a third party plug-in. The standard EQ in Pro Tools can only manage a slope of 24dB per octave at max. If I were going to try to explain slope in 26 words, it would be how quickly the response drops off below the cutoff frequency or above in a low pass filter, the sharpness of the filter in layperson's terms. Another advantage of using a third party plug-in for this demonstration is that anyone can have access to it, or a similar plug-in that has really high slope values available. This will work with a 24bB proactive slope, but it isn't as convincing for a demonstration. So I'm starting at 10Hz in the left channel so that everything gets through, then I'll raise the cutoff frequency up to 2kHz so that only frequencies above that point get through. In the right channel. I'm going to do the opposite, high-pass again, starting at 2kHz, then opening up to the full band above 10Hz. Let's listen again. It is exactly as we expect, except that I hadn't anticipated that the hi-hat would stay pretty much the same in the left channel all the way through. Well, of course it would as it's predominantly above 2kHz, I just hadn't thought about it. But I see this kind of unexpected occurrence as part of the fun. So that was high-pass. I think I should try low-pass. Sounds logical, doesn't it? I'm going to push the boat out a bit and sail closer to the wind, so I have low-pass filters in both channels, again with slopes of 120dB per octave. In the left channel I'll start at the highest cutoff frequency value, which is 30kHz and sweep down. And since my original session was at 48kHz sampling rate, I can guarantee that there's nothing up there other than maybe aliasing. I do sometimes miss the artifacts of 1980s digital audio. I digress. In the right channel. I'm doing the opposite, starting at 10Hz and going all the way up. Let's listen. This, I think you'll agree is a much stronger effect. There's probably some theory that would explain why, but I'm just going to take it as it is and say that if I want a mild effect I'll choose high-pass filters, for a strong effect I'll choose low. And with the low, well there's no way you'll get anything anywhere near close to this with conventional pan. You know, I enjoyed that so much I'm going to play it again. Now for something not entirely different. Something that's probably in the handbook of audio cliches is to start a track with some kind of effect that dulls it down in the intro then it opens up for the track proper. So you could start with a telephone filter, then open up to full frequency range. There's something else you can try if you haven't already. This in my experience works better with a quick or instant transition but a simple static telephone filter or any other kind of lo-fi, well, we can do something more interesting with filter pan effects. Let me play you some music flat so you know what we're dealing with, no pan automation, no filter. As you can hear, this is the start of a track and it could probably do with being made more interesting. I'm moving stage by stage on this, I'll add the low-pass filter effect that you heard previously. What I'm going to do now is use the same low-pass filter effect I used previously, but then I'm going to bypass the filters instantly at the start of bar six, so the five bar introduction is effected, then the track comes in clean. Yes I know, introductions are normally four or eight bars, but something must have been wrong with my counting when I made this track. Let's listen, five bars of effect, then instantly clean. I'll let the track play on a little longer this time so you can hear more of the clean audio to compare with the intro. So it's all in the initial and final settings of the cutoff frequencies and in the timing of the automation. One further point though is that I could have automated the cutoff frequencies so they were both at 30kHz at the start of bar six but on this occasion I automated the bypass. Call me old-fashioned but I'm not always trustful that bypass is actually true bypass and I've been caught out in the past with other plug-ins. I could therefore have put the intro on its own two mono tracks left and right and the rest of the audio on separate tracks or maybe a single stereo track with no plug-ins at all. Can I tell you a secret? I work a lot with video. I'm not gonna call myself an expert but what I do know is that to make a video sparkle on YouTube, you need to add lots of effects and transitions. Actually, I've been through that phase and I've come out the other end, but it did strike the thought in my mind that audio has lots of effects available. Come on, how many plug-ins do you have? But it doesn't have much in the way of transitions and those that we do have, other than press F for crossfade, are usually created pretty much manually. So I'm thinking crossfading between two different tracks rather than crossfading to prevent a click between clips. But other than crossfading tracks, there are plenty of reasons you might want to crossfade dissimilar elements of audio. You know where this is going? I'm going to crossfade two different tracks using my filter pan effect. First, I think we need to listen to a conventional crossfade using level automation. I said conventional, but conventionally you'd probably do it with the F key or whatever shortcut your DAW has. I've done it with automation on separate track because I'm going to add the filter effect in a moment. Here's the crossfade using level automation. I don't mind that, not too jarring and to be honest, other than setting the start and end points of the crossfade, I didn't take much trouble over it. But then obviously I want the filter pad crossfade to sound better don't I. So here's what's going to happen, I'm going to apply exactly the same level automation as in the example you've just heard, but also I'm going to have a downward sweeping low-pass filter in the right channel of the first track and an upward sweeping low-pass filter in the left channel of the second. It's not that complicated and I'll have another go at explaining it after I've played it. Well I like it and I'm sticking with that. What's often the issue with crossfading dissimilar tracks, particularly if they are at different tempe, is the clash between them during the actual fade. With the filter pan effect, to me, the transition is really quite a lot better. So to explain again what you heard, the first track faded out in level as the second faded in. The right channel of the first track was low-pass filtered with the cutoff frequency going down, the left channel of the second track was low-pass filtered with the cutoff frequency going up. That's probably as succinctly as I can put it, but it will be easier maybe just to hear it again. I'm going to end with one more example, this time of a filter pan effect on a single instrument inside a track. So one instrument moves, everything else stays in static pan just as I originally produced it, flattering myself to say it's produced, but there we go. It's another of my very irritating instrumental tracks I'm afraid, but I've chosen it because it has a section that's crying out for an effect. I'll play you an edit that starts with the tune, if I can call it a tune, for four bars followed by the section I'm going to redo. So now I'm going to raise the level of the track that I'm going to process and give it an upper mid-range boost so that it stands out more. At the same time I'm going to use a bit of EQ to make the drum track less prominent, then I'm going for it, the same filter and pan method that I demonstrated earlier but just on the one track. Here we go. Well maybe not so many points for artistic merit, but I'd say that if you're going to use this effect or this kind of effect in a track, then it should be planned in at an early stage rather than trying to be an ear candy afterthought. I hope you get the gist though and that's it for now. Going forward, next time you find yourself reaching for the pan control and wanting to automate it, remember that there's much more you can do by adding a simple filter or filters or eq, EQ and filters and why stop there? And as I said from the start, of course you can slap in a plug-in and dial up a preset and so can any other producer with the same plug-in but if you take some time and effort to construct effects for yourself, not just what I've done here, but with any processes you fancy, then you'll make your music more unique with more of an ability to stand out from the crowd. I'm David Mellor and you can find all of my irritating music on streaming and on Bandcamp, Irritating Unboxing Music is what to search for. See you soon. Thank-you for listening and be sure to check out the show notes page for this episode where you'll find further information along with web links and details of all the other episodes. Oh, and just before you go, let me point you to the soundonsound.com/podcast website page where you can explore what's playing on our other channels.