EQ tips for eliminating background noise from your mixes (a table of note frequencies)

Eliminating background noise from mixes[This article was written by Alex Andrews of Ten Kettles Inc. Their new music theory app, “Waay: Music theory that matters” is now available. Click here to learn about its video lessons, interactive exercises, progress-tracking tools, and more.]

What’s the frequency of C, and why should you care?

It’s 261.6 Hz. Why would we ever need to know this? Well, there could be a few different reasons, but one has to do with mixing audio. When equalizing (EQing) an audio track, one common challenge is filtering out background noise—especially if the track was recorded with a microphone. Here’s what the mic might be picking up:
* The rumble of a streetcar or truck going by in the distance
* An accidental knock of the microphone stand
* A door closing somewhere in your building
Your best route to eliminating background noise is to cut it out at the source, but in many cases (barring time travel) that’s just not possible. So we use an equalizer, or EQ, to lend a helping hand.
Take a guitar track for example. What’s the lowest sound you’d expect to come from a guitar? If it’s in standard tuning, the lowest string is tuned to E2, which has a frequency of 82.4 Hz (see the table below). This means that any sound below ~80 Hz is not guitar. So, if we filter out everything below that frequency, we cut out the low noise (like the streetcar rumble) but keep all that great guitar sound. Not bad! The name for this kind of filter is ahigh-pass filter, because it lets all the high frequencies pass—and keeps out the low ones.
Below is a table of all the note frequencies, with the highest and lowest notes of various instruments highlighted. The first column is the octave number. For example, the low E string on a guitar is tuned to E2—that’s E in the 2nd octave.
NoteFreq. (Hz)Instrument
0C16.35
C♯/D♭17.32
D18.35
D♯/E♭19.45
E20.60Approximate lower limit of human hearing
(increases with age)
F21.83
F♯/G♭23.12
G24.50
G♯/A♭25.96
A27.50
A♯/B♭29.14
B30.87Lowest note of a 5-string bass
1C32.70
C♯/D♭34.65
D36.71
D♯/E♭38.89
E41.20Lowest note of a 4-string bass
F43.65
F♯/G♭46.25
G49.00
G♯/A♭51.91
A55.00
A♯/B♭58.27
B61.74
2C65.41
C♯/D♭69.30
D73.42
D♯/E♭77.78
E82.41Lowest note of a guitar
F87.31
F♯/G♭92.50
G98.00Approximate low-end of male vocals
(depends greatly on individual)
G♯/A♭103.8
A110.0
A♯/B♭116.5
B123.5
3C130.8
C♯/D♭138.6
D146.8
D♯/E♭155.6
E164.8
F174.6
F♯/G♭185.0
G196.0Approximate low-end of female vocals
(depends greatly on individual)
G♯/A♭207.7
A220.0
A♯/B♭233.1
B246.9
4C261.6(Middle C)
C♯/D♭277.2
D293.7
D♯/E♭311.1Highest note of a 4 or 5-string bass
E329.6
F349.2
F♯/G♭370.0
G392.0Approximate high-end of male vocals
(depends greatly on individual)
G♯/A♭415.3
A440.0
A♯/B♭466.2
B493.9
5C523.3
C♯/D♭554.4
D587.3
D♯/E♭622.3
E659.3
F698.5
F♯/G♭740.0
G784.0Approximate high-end of female vocals
(depends greatly on individual)
G♯/A♭830.6
A880.0
A♯/B♭932.3
B987.8
6C1047Highest note of a 20-fret guitar
C♯/D♭1109
D1175
D♯/E♭1245
E1319
F1397
F♯/G♭1480
G1568
G♯/A♭1661
A1760
A♯/B♭1865
B1976
7C2093
C♯/D♭2217
D2349
D♯/E♭2489
E2637
F2794
F♯/G♭2960
G3136
G♯/A♭3322
A3520
A♯/B♭3729
B3951
8C4186
C♯/D♭4435
D4699
D♯/E♭4978
E5274
F5588
F♯/G♭5920
G6272
G♯/A♭6645
A7040
A♯/B♭7459
B7902
9C8372
C♯/D♭8870
D9397
D♯/E♭9956
E10,548
F11,175
F♯/G♭11,840
G12,544
G♯/A♭13,290
A14,080
A♯/B♭14,917
B15,804
10C16,744
C♯/D♭17,740
D18,795
D♯/E♭19,912Approximate upper limit of human hearing
(decreases with age)
E21,096
F22,351
F♯/G♭23,680
G25,088
G♯/A♭26,580
A28,160
A♯/B♭29,834
B31,609
—-
Bio: Alex Andrews is an engineer, musician, and runs Ten Kettles Inc in Toronto, Canada. Ten Kettles is an indie app company that builds apps for music education. Their newest app, “Waay: Music theory that matters,” brings together video lessons, interactive exercises, and progress-tracking tools to teach music theory for songwriters. You can find out more here.
Free Updates: Become a 
Smarter Musician
How to spread the word 
about your music: 
online marketing tips to help you connect with fans and sell more music.
[Picture of console from Shutterstock.]
Visit Website
follow us in feedly Instagram submit to reddit