part2

Various Effects

• With Pd we can make various effects

• The programs of some basic effects will be introduced in this section

• You can make your original effects by combining effects

Distortion

• clip~ clips incoming signal using min and max values provided as arguments

• We can magnify the audio signal by *~ and then clip it with clip~. In this way, we can intentionally create distorted audio signal

Delay

• The combination of delwrite~ and delread~ enables us to delay the incoming signal

• delwrite~ name_of_buffer max_delay_time

• delread~ name_of_buffer delay_time

• name_of_bufer should be identical on delwrite~ and delread~ (e.g. delay1)

• you can adjust the delay time by changing the argument of delread~ or sending numbers to delread~.

• dealread~ does not accepts delay time above max_delay_time

Feedback Delay

• echo effect

• attenuate the output from delread~ and feed it back to delwrite~

• do not amplify the signal with *~

Ping pong delay

• you can create more than one delread~ for one delwrite~

• the delay time of each delread~ can be different

• connect two dealread~ with defferent delay time to the left and rigt inlets of dac~

Vibrato

• delay time can be continually fractuated by using vd~ (variable delay) and osc~, the produces the vibrato effect

Chorus

• by combining multiple vibrato, you can make a chorus effect

Flanger

• by combining feedback delay and vibrato, we can create flanger effect

Filter

• There are simple filters as objects in Pd

• hip~ highpass filter; cut out the low frequency component

• lop~ lowpass filter; cut out the high frequency component

• bp~ bandpass filter; bypass the specified center frequency range and cut out the rest

Wah-wah

• vcf~ is similar to bp~ but the center frequency can be also controlled by signal

• we can combine line~ and vcf~ and smoothly change the center frequency parameter for example

Auto wah

• by combining osc~ and vcf~, we can change the center frequency upward and downward alternatively.

Reverb

• reverb effect can be achieved by combining many delays. However, there is rev1~ in the object collection of Pd-extended. With this object, we can add reverb effect very easily.

How to make your own effect

- you can combine multiple effect

distortion -> chorus -> reverb

Synthesizer

- There are many ways to make synthesizers in Pd

- additive synthesis

- subtractive synthesis

- physical modeling synthesis

- FM and PM synthesis

- Phase Distortion synthesis

- Waveform synthesis

- Waveshaping synthesis

- Granular synthesis

Adding vibrato to a sine wave

• In the patch osc~ on the topcontrols the frequency of the buttom osc~

• 440 Hz is called carrier frequency, 6 Hz is called modulation frequency, 31 Hz is called modulation index

• The modulation frequency determines the speed of vibrato, and the modulation index determines the depth of vibrato

Very fast vibrato

• • we are not able to perceive it as a vibrato and start to perceive it as timbral characteristic

  • This is called FM synthesis

Making harmonic tone

• • We can recognize multiple pitches from the generated FM tone because the partials are inharmonic.

  • If we adjust the modulation frequency multiples of the carrier frequency, we can make harmonic tone

  • The modulation index controls timbre

To generate only harmonic tones

• • by using * object, we can restrict the modulation frequency to the multiple of carrier frequency

Envelope

• • By applying an envelope to a tone, we can determine how a tone starts and ends.

  • In the following example, attack time = 50 msec. / release time = 500 msec.

Changing modulation index automatically

• • In the following patch, line~ changes the modulation index (the timbre) gradually

Play the synthesiser with the musical scale

• • mtof converts MIDI note number to frequency

  • e.g. 60 means C4 (the middle C on the piano piano keyboard)

Play the synthesizer with computer keyboard

• • As we did for sampler, we use sel and use the computer keyboard as a MIDI keyboard

  • keyname is different from key. It outputs a character (symbol) from the right outlet when a key is pressed. The left outlet outputs 1 when the key is pressed and 0 when the key is released.

Adding Reverb