Boosting the highs a bit is a time-honored mixing and mastering technique. You don’t want to overdo it, but a little brightness can give a song a lift, increase vocal intelligibility, articulate instruments better, and add some welcome “ear candy.” If you look at the spectral energy of a lot of hit records going back decades, you’ll often find a few extra dB of boost in the 7 to 10 kHz range, to add some “air” and sweetness.
So just boost the EQ a little bit, right? Well, that’s one option…but we can do better. The Air Machine FX Chain (Fig. 1) is equally at home on individual tracks in the Song page (try it judiciously on drums, drum room mics, acoustic guitar, piano, vocals, etc.), or on finished mixes in the Project page. And yes, there’s a download at the end so you don’t even have to create this yourself.
Here’s how it works. By choosing the Splitter’s Frequency Split mode (outlined in orange), the Splitter acts as a crossover that sends the high frequencies through the right-hand split. The default crossover frequency is 7 kHz, but we’ll have more to say about this later.
The high frequencies then go through the Binaural Pan processor, which spreads out the stereo imaging. Because high frequencies are very directional, this not only increases the sense of “air,” but the feeling of space. Then, the Mixtool adds the appropriate amount of high-frequency boost.
As to assigning controls to the FX Chain, see Fig. 2.
The Air Width parameter alters the Binaural Pan Width parameter over its full range. The Air Boost control sweeps from no boost (0 dB Gain on the Mixtool) up to a maximum of about 6 dB. You really don’t want to go any higher than that.
The one control I couldn’t put in the FX Chain was the Splitter’s crossover frequency, so you may want to open up the FX Chain to alter this. The higher the frequency, the more boost you can apply without the high frequencies becoming overbearing. Sometimes, though, you might want to bring the crossover frequency down to 5 kHz or so if you want a more pronounced effect…or even up to 10 kHz for just a light dusting of high frequencies.
Yes, it really is that simple. And yes, the effect is best when used subtly. But try it—I think there’s a chance this may end up becoming one of your favorite FX Chains.