The humble filter is such a standard part of any producer's arsenal - found on everything from synths, to samplers, to standalone filter plugins of every hue - that it's easy to forget how much of a useful creative tool a good filter can be. In the endlessly re-routable environment of the modern DAW, this is more true than ever. So let's take a look at how filtering can help you find inspiration, help your mixdowns, and more....you!We'll assume that you're aware of the standard, filtered house, low-pass filter kind of use. Take your lead riff (a disco sample, synth chord progression, brass section or whatever), maybe sidechain it off the kick, and gradually increase the LPF cutoff to increase the hype level of the track. Consider turning down the Resonance as the filter gets up to the top, to reduce harshness in the mix. It's simple, it works every time, and it's something you should have in your repertoire. But there's a lot more to filtering than that. For a start, in a case like this, try assigning your filter cutoff to the modwheel of your controller and jamming in some live filter tweaks to give the track a little more variety.
Stuck for an interesting riff? Try putting a filter with a sidechain input and envelope controls on a channel with some simple pads or sounds. Then set the sidechain signal to be something rhythmic; perhaps a steady beat like a kick drum, or something busier and more syncopated like a full drum track. By tweaking the input and envelope controls you'll be able to get a funky filter effect that will give a load more interest to a standard part. Chuck a tight delay on there for instant techno and trance chord pulses. You could even insert a side-chained noise gate before the filter to really emphasise the rhythmic nature of the effect.One technique which can radically change the sound of your drums, and the track overall, is to bounce them down to a stereo file, then put an autofilter on the result. Use a low-pass filter, set the LFO cycle to one crotchet (half a bar if you're feeling adventurous) and let rip - you'll hear the filter sway up and down rhythmically, and if get the phase right you can have it open for the high hats and off-beat percussion, closed for the kicks, and sweeping through the rest for a crazy, dubbed out, swing sound. It really gives a different feel for a track, and can inspire a whole new take on a tired sound in need of a spruce up.
Bass warriors will be well aware of the potential for filtering to create the gnarliest sounds possible. There are plenty of techniques, and one of the most popular right now is formant filtering - it gives that vowel sound, the 'yoy' noise so beloved of the hardcore dubsteppers. Logic comes with one built-in (the EVOC filter) but the true daddy of this sound is, of course, NI's unparalleled synth Massive. It's far quicker to watch one of the many Youtube tutorials on this than it would be to write a point-by-point guide, but in summary you need to sweep the filter cutoff and the formant settings for full effect.
The classic 'wobble' sound - assign the filter cutoff to an LFO - though somewhat standard, is still useful, however, especially when the LFO is tempo sync'ed for a rhythmic feel. But then, try another filter after that one in the chain, with a band-pass filter on it. Then turn up the amount of the dry signal close to 100%, so that in effect you're getting an EQ boost around the area of the bandpass. Sweep this up and down the frequency spectrum to really mess with the sound. As you're getting an EQ spike, you'll need to tame the dynamics though. Limiters are good, but for huge bass sounds, what better than a distortion unit? It will tame the peaks and give the sound even more bite.Filtering can also help with technical issues, such as mixdowns. Many uses are commonly known, although still good practice; filter out any frequencies you don't need. Hi-hats can generally be high-passed at 2kHz or more (unless you're going for that graunchy hip-hop sound), pads should usually be high-passed somewhere above 200Hz to remove muddiness, and reverb and delay returns can be bandpassed - they don't need anything below about 500Hz taking up all your midrange headroom, and they also don't much above 5kHz confusing that top-end detail.
So filters can help your sound across the board - whether generating inspiration to help get an idea moving, to tweak and hype up a riff or a bass sound as you arrange the track, and then finally when mixing the whole thing down afterwards. So don't overlook this essential keystone of any producer's repertoire - get those filters working for you!
