Effects (Hardware and digital)

Question 1

Phaser

Answer 1

• A copy of the signal is made and is passed through an ‘all pass filter’ which introduces a phase shifting around a certain frequency
• They work by stringing several all-pass filters together in a series of non-harmonic notch filters

Question 2

Chorus

Answer 2

• A copy of the signal is made
• LFO is applied to modulate the delay time, which causes gradual changes in the frequency
• The copied signal is mixed with the original
• The duplicated signal slightly varies in pitch and time
• Chorus units will create notches in lower frequencies due to their longer delay times.

Question 3

Flanger:

Answer 3

• A copy of the signal is made
• An LFO is applied to the signal and mixed with the original
• Because the copies of audio are identical, interference will begin to occur. Resonances will be created at some frequencies and a series of notches will be created across the frequency spectrum. Called a comb filter

Flangers have shorter delay times, notches will be created in mostly high frequencies.
Because the notches in flangers are generated by frequency relationships within the signal itself, they will occur at harmonically related intervals (based on the frequency content of the original signal).
By using an LFO to modulate the copy’s delay time, these points of interference will change. The notches on the comb filter will appear to “move,” resulting in a searing resonance that sweeps to the rate of the LFO.

Flangers also make great use of feedback, sending the output back to the input to receive more processing. This accentuates the notches and resonances, resulting in the harsh, metallic timbre characteristic of flangers

Question 4

Vibrato

Answer 4

Changes volume at chosen rate

Question 5

Wah

Answer 5

Automates the bandpass filter