Mixing is both an art and science. Why? It is an art because there are no limitations in being creative. It is a science because there are methods to be followed.
Supposing you have completed the recording and panning process. It is the proper time to start mixing the frequencies of the instruments. A song which is not mixed properly can result to poor quality sound recording.
I did myself some educational recording and mixing of my own song “At the highway”
I played and recorded all the instruments (guitar, bass and drums) in multi-track and the vocals are performed by Jeanine Maningo
There is no bass guitar involved. Listen to the sound clip below which the frequencies are still not mixed for clarity. (Although panning and recording process are done)
This mix does not include the bass guitar mixing:
Problems in the Original Mix
A quick critic to this mix is as follows:
1. Guitars dominating the mix.
2. Muddy guitar sound.
3. Kick sounds so weak looks like punching a pail.
4. Vocal lower frequency range in conflict with lower guitar frequencies and kick.
Though this is a demonstration of music production at its simplest form, it has been illustrated, that muddiness of the mix can be corrected at the early part of mixing process and should not be a part of mastering process.
Improving by properly mixing instrument frequencies
Below is the corrected mix with proper mixing settings applied:
What can you say? Clear is it? Yes I admit it is. The kick and the rest of the instruments are not fighting with each other, so guitar sound is so clear and not conflicting with either the vocals. Overall, the sound is not muddy. The secret in doing this, is very expensive in recording schools. But I will reveal below:
Rule #1. Each music instruments has it’s own center frequencies and range. Use a parametric equalizer to adjust.
Rule #2. Cut and boost conservatively depending on the resulting sound.Q setting of a parametric equalizer is important.
Some background on Q and Center Frequency in Parametric EQ
Here we introduce “Q” and parametric equalizer, what are those things?, Q is a measurement of how narrow or wide the frequency adjustment on a parametric equalizer. Parametric equalizer is a mixing tool that will enable you to manipulate frequencies of instruments and balance it in the mix, just like what a paint brush will do to a painter.
To simply understand Q:
a.) a Q of 1.0 could be considered as medium wide.
b.) a Q of less than 1.0 is considered to be wide frequency adjustment.
c.) a Q of 1.4 is average adjustment.
d.) a Q of greater than 2.0 is a narrow adjustment.
Also there is what we call as “shelving”. It can be classified as low pass filter or high pass filter. A low pass filter will preserve low frequencies and cut frequencies higher than the cut off. High pass filter will preserve higher frequencies but cut frequencies lower the cutoff frequency.
A center frequency is a frequency where maximum amplitude occurs. In layman term, it is a frequency most noticeable by the ear of that instrument. Let say voice frequencies. It is around 300Hz to 3000Hz that is wide range, but that is the bandwidth of a telephone line. It is why the telephone lines are optimized for voice transmission.
The center frequencies of that bandwidth are around 1650Hz~2000Hz. It is where the voice frequency is strongest. And during a mixing process, that certain spot in frequency range is reserved for the voice to avoid conflict with other instruments.
Also take note the amplitude adjustment in parametric equalizer are measured in dB (decibels).
EQ Settings used in the Improved Mix
Below are the list of common instruments I used to mix “At the highway” and the EQ adjustment :
Short Snare
Freq1: 100Hz, Boost 1dB, Q 1.0
Freq2: 2500Hz, Cut 3dB, Q 1.4
Freq3: 8000Hz, Boost 2dB, Q 1.0
Purpose- 100 Hz serves to fatten the snare sound; cutting at 2500 Hz will minimize conflict with vocal frequencies. Boosting at 8000Hz will add some crisp (audible snare strings)
Kick Drum
Freq1: 75Hz,Boost 6dB,Q 1.0
Freq3: 400Hz, Cut 6dB, Q 1.0
Freq4: 4000Hz, Boost 1dB, Q 0.6
Purpose- Boosting at 75Hz creates super-punch for the kick. Cutting at 400Hz can prevent conflict guitar lower bass and improves kick sound by removing the cardboard like sound. Boosting at 4000Hz can make the kick sound to be heard on small speakers such as headphones.
Guitar
Freq1: 160Hz, high pass filter, Cut 6dB
Freq2: 3000Hz, Cut 9dB, Q 1.0 (Cutting this prevent direct mud sound with vocals which occupies the same frequency range)
For more details, it is recommended to read the following tutorials (as well as the related tutorials below):
a.) EQ settings for audio mixing
c.) Attaining clarity in mixing sessions
Content last updated on June 14, 2012