Equalizers

1
Equalizers

• Tone controls (Shelving Filters)
• Graphic Equalizer
• Parametric Equalizer

Total Recording, pp. 243-256
2
Graphic Equalizer
Many Selectable Frequencies Fixed Bandwidth
(Q) Typical Applications Live Sound Room Tuning
3
Parametric Equalizer
Precise Frequency Selection Variable
Bandwidth (Q) generally 0.5 to 3 or 5 Typical
Application Recording
4
Paragraphic Equalizer
Somewhere in between
5
Digital Equalizer
Ultimate Flexibility, perhaps not quite the
fidelity of analog. Typical Application Live
and Recording
6
General Frequency Considerations

• Fullness - Boosting frequencies in the 100-300 Hz
  range. Careful of adding too much and making the
  recording muddy.
• Articulation - Enhanced by adding transient range
  of a given instrument, typically in the 1-4 kHz
  range.
• Closer/Farther - Boosting with a shelving filter
  in the 10-12 kHz range will make a recording
  sound closer. Can also add air to the
  sound.Percussion Crispness - 1-2 kHz

7
Warnings!!!

• The less EQ the better!
• You can ruin a good recording by using too much
  EQ. Think of EQ as a spice a little can be
  really great, but too much can destroy a
  recording.
• Mic choice and placement should be primary
  considerations when looking to change a sound, EQ
  should be the last resort.
• There are good Equalizers and bad Equalizers.
  Listen carefully to what youre doing
• Is stereo image being effected?
• Is more than the frequency youre adjusting being
  effected?

8
Frequency Ranges of Interest

• Kick Drum - Bottom at 60-80 Hz, Slap at 2.5 kHz
• Snare Drum - Bottom at 240 Hz, Crispness at 5 kHz
• Hi Hat/Cymbals - Shimmer at 8-12 kHz, Tone at 200
  Hz
• Rack Toms - Fundamentals from 200-300 Hz, Attack
  5 kHz
• Floor Toms - Fundamental 80-120 Hz
• Conga/Bongo - Resonance at 200-240 Hz, Slap/Hand
  5k
• Bass Guitar - Bottom 60-80 Hz, Pluck 800-1000 Hz,
  String Pop around 2.5 kHz
• Elec Guitar - Fullness 240 Hz, Bite at 2.5 kHz
• Acous. Guitar - Bottom 80-120 Hz, Body 240 Hz,
  Pick/Clarity 2-5 k

9
Frequency Ranges of Interest(cont.)

• Electric Organ - Bottom 80-120 Hz, Body 240 Hz,
  2.5k Presence
• Acoustic Piano - Bottom 80-120 Hz, Presence
  2.5-5k, Crisp attack around 10 k, Honky
  Tonk Sharp Q at 2.5k
• Horns - Full at 120-240 Hz, Shrill 5-7.5 k
• Strings - Full at 240 Hz, Bow Hair/Strings
  7.5-10k
• Vocals - Full at 120 Hz, Booy 200-240 Hz,
  Presence/Consonance at 5k, Sibilance at 7.5-10 k
• Telephone - wide bell with 3k Center

10
Where on Channel Strip?Where in Signal Chain?
Before or After Compressor
11
Common Console Design

• Quasi Parametric
• Hi Shelf
• Hi Mid Parametric (w/o Q usually)
• Lo Mid Parametric (w/o Q usually)
• Lo Shelf
• HPF
• LPF (rare)

12
Filters

• High Pass - Reducing or eliminating unwanted low
  frequency content. Generally build-up from
  Proximity Effect, or low noise rumble.
• Low Pass - Generally used for reducing high
  frequency noise such as tape hiss, noise from
  poor AD converter. Also used in digital audio as
  a Anti-Aliasing filter.
• Band Reject - Sometimes called a notch filter,
  will allow engineer to eliminate a specific
  frequency by as much as 60dB.

13
Know your Frequencies!!!

• GOLDEN EARS
• By David Moulton