How to Apply EQ to Music Tracks Recorded on Your iPad or iPhone

By Ryan C. Williams, Mike Levine

Equalization lets you adjust the frequencies present in a track you recorded on your iPad or iPhone to either reduce problems or make the part stand out in an area that no other instruments occupy. Every instrument or port occupies a sonic space in your mix, and your goal should be to find a place for each part in the mix to let that part stand out.

So where do conflicts arise? You’re more likely to see clashes where the instruments try to occupy both the same role and the same sonic space. Think about the low end, where the kick drum, the bass guitar, and the low end of the keyboard hang out. Those frequencies can get muddy and mixed up easily just by virtue of being in that sonic range, but the amount of instruments playing down there can cause issues as well.

You can use equalization to reduce frequencies on these instruments to make sure they all stand out. You can also use a high-pass filter on the instruments that automatically cuts all frequencies below a certain level to keep the track’s rumble from getting out of control.

On the other side of the spectrum, you can add a little high end to parts to give them a little sparkle and shine, or take the high end down a bit to eliminate any harshness. Higher frequencies tend to stand out more on earbuds and systems with smaller speakers, so making sure these parts stand out without overpowering the song should be a high priority.

And then, of course, you must make sure everything else falls into place. Keyboards and guitars take up a lot of sonic space, and you must find a place for each part in the mix.

Don’t forget about vocals, either — you need to find the right frequencies for any singers to show off the unique nature of their voices. Every instrument and voice has a unique sound and emphasizes certain frequencies more than others.

This section gives you a little better idea of the frequencies common instruments use and where you can tweak those instruments to bring out the sound you want.

All values on this list are approximate. These instruments generally find themselves in this range, but actual results may vary depending on construction and where you record the instrument.

  • Drums:

    • Bass Drum: 50 Hz to 5 kHz.

    • Toms: 80 Hz to 7 kHz.

    • Snare Drum: 100 Hz to 10 kHz.

    • Cymbals: 200 Hz to 12 kHz.

  • Bass Guitar: 30 Hz to 5 kHz.

  • Guitar: 70 Hz to 5 kHz.

  • Keyboard: 27 Hz to 4.3 kHz.

  • Brass: Anywhere from 30 Hz to 2 kHz for a tuba to 170 Hz to 9 kHz for a trumpet.

  • Woodwinds: Saxes and clarinets can range from around 120 Hz up to 13 kHz.

  • Male Voice: Anywhere from 100 Hz to 16 kHz, depending on the vocal range of the singer.

  • Female Voice: Anywhere from 250 Hz to 16 kHz, depending on the vocal range of the singer.

So what’s with the big range of frequencies? Every note has a fundamental pitch (the main note you hear) and a series of overtones (different frequencies that you also hear that give the instrument its characteristic sound, also known as timbre). As you boost or cut frequencies along the range of the instrument, you change the characteristics of the sound.

  • Frequencies from 20 Hz to around 250 Hz add the low bass and rumble to sounds, but can quickly overwhelm a mix.

  • Electrical hum occurs at 60 Hz in the United States. If you hear that kind of hum or have grounding issues, this frequency is where the sound occurs.

  • Frequencies from 250 Hz to 800 Hz can sound a little more bass presence, but watch that you don’t make the sounds too muddy.

  • Frequencies from 1 to 6 kHz can emphasize the fundamentals of most notes, but watch that the sounds don’t overwhelm other instruments in the same range or become too tinny or honking.

  • Anything above 6 kHz adds high-end frequencies to the instrument, from the sizzle of cymbals to air and shimmer on other instruments. These frequencies can add to your mix, but they can quickly become annoying if you add too much.

  • Vocal sibilance can occur between 4 kHz and 10 kHz, depending on the range of the voice. If you hear too much emphasis on the “ess” sound of your vocals, you may want to look at reducing those frequencies.

If you have to add more than three or four dB to an instrument, you might want to think about cutting other frequencies on the track to compensate. Boosting the EQ adds gain to the overall tracks, and you could be adding peaks that affect your headroom and possibly cause distortion down the road.

You might also think about reducing the EQ of other frequencies in the signal (subtractive EQ) as opposed to raising the EQ of the frequency you want (additive EQ) to make sure your signal doesn’t get too out of hand.

Here, you see a bump up on the boom on the kick drum — it’s a little thin as it is. To alter the EQ in Auria, tap the FX button, pull up the EQ section, and use the lower frequency EQ to select 60 Hz and bump that frequency up around 3 dB.

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Boosting bass frequencies without the aid of a professional monitoring system can get a little hairy, because a number of systems can’t accurately reproduce those frequencies. Make sure you use a monitoring system that can handle bass frequencies before playing around with these sonic ranges.

The EQ used in this example is a parametric EQ, which allows you to select both the frequency and the amount of gain you can add or cut.