iZotope’s Mobius Filter plug-in applies the Shepard tone concept—an auditory illusion of continually rising or falling pitches—to filters. Depending on the direction you set, Mobius Filter will run infinitely ascending or descending filters that sweep through audio to create the impression of constant spatial motion.
Static audio can be boring. So live it up with filters that build excitement and release tension. In this article, I’ll show you five practical ways to use Mobius Filter for more expressive, interesting music production.
In recent years, the drop has become an increasingly popular, often dramatic feature of electronic music. We all the know the story—a song builds up to its highest point, then “drops” into a new section with a bassline, sending listeners into a dance frenzy.
Part of what determines the effectiveness of a drop are the seconds that lead up to it (usually between 5–15 seconds). Within this short amount of time, you need to pack a lot of anticipation and energy into your music production, giving listers the cue that things are about to get wild. Here’s one way to do it.
I’m working with a drop that pulls out all the familiar stops: snare rolls, whooshes, and white noise.
I set Mobius Filter’s filter direction upward to enhance the forward motion of the buildup and automated the blend to move from dry to wet over it’s duration, so as not to overdo the effect. For extra zing, I increased the filter speed from 0 Hz to 9.6 Hz during the last few seconds, right up to the final whoosh, then back down to 0 Hz. If you prefer, filter speed can also be tempo-synced from 8 beats to 1/8 notes.
The dramatic filter rate increase near the end of the buildup produces a series of wobbly sweeps just as Mobius Filter approaches a full wet blend. These moves add an extra degree of excessiveness to the buildup and maximize its potential for dancefloor destruction. Of course, a drop’s effectiveness also teeters on what comes after it. But I’ll leave that part up to you.
Pads have a wonderful atmospheric quality. At low volume levels, they reinforce other song elements, but they can also be the main focus of a song when a dreamy, relaxed mood is the goal. If you already use pads in your music, you’ve probably noticed they can start to sound flat after a few bars if there isn’t any movement-based processing applied. The solution: add subtle filter sweeps with Mobius Filter that create the impression of an arching motion from one chord (or note) to the next.
Drag the golden ring across the X axis to produce a filter that modulates frequency only. Slowly add in resonance by moving the golden ring upward, engaging the Y axis. Stop once the resonance whistling becomes obvious—this is the sweet spot where pad sweeps sound best.
Listen as I slowly increase Mobius Filter frequency modulation on the pads, then pull up resonance. The speed is set to 2 bars to match the length of each chord and the filter type is set to Phaker, which applies both frequency peaks and dips.
Updating old music production aesthetics with modern day equipment is a common practice among producers of all genres, styles, and tempos. Get in touch with your psychedelic side and add Mobius Filter to guitars, synths, and even vocals for a shimmering surfer-rock-meets-80s-pop effect.
Here’s the guitar sample I’m working with, with no effects.
At high speed settings, Mobius Filter produces a pulsating, watery sound that pairs well with guitars. I set the filter speed to 6.5 Hz, stereo widening to 36%, and dry/wet to 18%. If the wet signal is any higher, the effect will sound too obvious and lose its authenticity.
I still need some help from friends to really nail this aesthetic. Vinyl’s pitch warp and boosting frequencies with EQ around 3 kHz will add the vintage recording flair I want. There’s also tremolo added in via Ableton Live’s Auto Pan.
In recent years, artists like Homeshake have used similar processing to achieve their lo-fi guitar sound.
Apply Mobius Filter to high frequency-rich percussion and shakers to produce zaps, swirls, and chirps that add a fun, colorful energy to your music production. This is particularly useful for upbeat styles like house, disco, and boogie.
In this disco loop, Mobius Filter filters the tambourines at an alternating speed of 1/8 notes and 10 Hz, with a high resonance of 95 (out of 100). At the end of every four bars, the dry/wet is increased from 40% to 100%. Together, these settings produce a laser-like sound guaranteed to get audiences to throw up their finger pistols.
The first four bars are dry, and the following four include Mobius Filter on the tambourines.
The key ingredient behind the laser sound is resonance. Resonance enhances or boosts frequencies around the edge of a cutoff frequency, in this case, making the sweep more noticeable. At a higher filter rate, the sweeps will start to sound like chirping synthetic birds.
This is what resonance looks like on an EQ. The Q boosts the resonance. Bear in mind—at very high resonance levels, you will produce an unpleasant ringing sound that isn’t fun at all!
Mix up your mix
So far, the examples in this article have used Mobius Filter on a single mix element. What about applying Mobius Filter to an entire mix?
During the sections of your song that have a lot of open space—typically an intro, breakdown, or outro—use Mobius Filter at low settings to add excitement.
Here is a song intro, with no effects.
And now, with Mobius Filter frequency modulation.
Listen closely and you will hear slithering sweeps that add a unique, flowing quality to the mix. It’s a minor detail, but one that will give your music a hint of something special.
Set it and forget it
In this article I showed you five ways to use Mobius Filter in your music: to maximize buildups, excite pads, recreate vintage qualities, shakeup percussion, and sweeten entire mixes.
Hopefully you are inspired to try these tricks out in your own productions, as well as come up with a few new ways to use Mobius Filter for more movement.
Learn more about Mobius Filter.