When you hear about “air” on vocals, the reference is to that subtle, frequency halo in the high-end of the vocal sound. A pleasant high-frequency icing on the top, which can add a little more excitement to a vocal track. In this excerpt, F. Reid Shippen shows a handy trick for adding air to vocals.
Airing it Out
The first thing Reid does is duplicate the vocal track. He’ll be adding processors to the track copy to create this effect, so you can consider this to be a form of parallel processing. For this article, we’ll refer to this parallel track as the “air” track.
Next, he inserts iZotope Nectar, an all-around vocal plug-in on the air track. He says he chose it because it has both EQ and limiting in the same plug-in, and he’ll need both processes for this technique.
Reid uses a preset that he created, which has the requisite settings. In Nectar’s EQ module, he set what appears to be a high-pass filter with its cutoff frequency in the neighborhood of 5kHz, with a steep roll-off. The idea is to filter out everything but the high-frequencies. He sets the limiter to process heavily, which helps bring the air track’s level up to a suitable place. Because he’s cutting out so much of its frequency range, the duplicated vocal would sound extremely quiet without the boost provided by the limiter.
The EQ setting Reid used in iZotope Nectar
Vocals in the Air
He plays the air track soloed with the processing, and it sounds thin and kind of buzzy. He explains that he also reverses the polarity (which is referred to as “phase” in a lot of plug-ins), which he’s presumably doing to create phase cancellations that thin the track out more.
He then plays back the original vocal track and blends in the air track. He describes the sound it creates as a “pop sheen.” He suggests that once you have the balance between the original vocal track and the air track, you should group them so that when you adjust them in the mix, they’ll maintain their relative levels.
Reid says the technique is also useful for adding clarity to a track that was inadvertently recorded with distortion in some spots. The sound produced by the air track can also divert attention from the distortion, particularly in the midrange.
Reid also demonstrates the technique with individual plug-ins. For EQ, he uses FabFilter ProQ2 with these settings.
You can use any plug-in that has both EQ and limiting to create this effect, Reid says. Or you can use separate EQ and limiting plug-ins, it doesn’t matter. He demonstrates the latter with a pair of FabFilter plug-ins: Pro Q2 and Pro L2. This time not only does he filter out everything below about 5kHz, but he also adds a shelving boost at approximately 11kHz.
Here are step-by-step instructions for Reid’s “air” trick:
- Duplicate the vocal track
- Insert an EQ plug-in (or channel strip that contains both an EQ and a limiter) on the duplicate and use a high-pass filter with a steep roll-off (-24dB or more) set to around 5kHz. You want to hear only the buzzy, top end of the vocal.
- Add a limiter after the EQ and set its threshold roughly at -25dB to create a substantial amount of processing.
- Flip the polarity (“phase”) of the copied track (this step is optional) to thin the air track more. If neither your EQ or limiter plug-ins have a polarity reverse switch, insert another plug-in into the chain that does.
- Find a good level for the copied track vis-a-vis the original vocal track, and then group the two tracks so that when you change the vocal level in the mix, their volume relationship remains the same.
Air Alternatives
In addition to Reid’s technique, there are several other ways to add air to vocals.
A more traditional method is simply to use an EQ with a boost in the top end. The Maag EQ is particularly well known for its “Air Band,” which is a high-shelving filter that gives you a choice of 2.5, 5, 10, 20 or 40kHz. The folks at Maag jokingly refer to that highest setting as being, “bat-bothering.” Although the Maag EQ is an excellent choice for adding air to a vocal, you can get decent results with almost any EQ with a shelving filter set in the 10-15kHz area.
Example 1: Here’s a vocal track soloed. The Maag EQ is bypassed for the first four measures, but comes in, boosting pretty heavily at 20kHz, right after she sings “fall asleep.”
The UAD Maag EQ plug-in settings for Example 1.
Another way to go is to insert an exciter on the vocal track (no parallel processing required for this method). An exciter typically adds both EQ and saturation, usually in the high-end, which helps to create a buzzy warmth that’s similar to what you heard from Reid’s technique in the excerpt.
Example 2: Here’s the same vocal as in Example 1, with the processing coming in at measure five, the same spot as in the previous example. This time, it’s iZotope Neutron 3 doing the processing, with its multiband exciter module, set to affect only frequencies above 4.8kHz.
The exciter setting in iZotope Neutron 3 used in Example 2.
You can also simulate what an exciter does with a combination of EQ and saturation plug-ins.
Example 3: Once again, the processing doesn’t come in until measure five. In this example, it’s Waves Abbey Road Saturator, applied in parallel via an aux send, and Waves PuigTec EQP-1a (a Pultec emulation) boosting by a little less than 5dB at 16kHz.
The settings used in Example 3, in which both EQ and Saturation were used to create air on a vocal.