MUS271A (Max w8) – granular patches

Here are all the patches for this topic: 06-granular


 

Screen Shot 2018-02-27 at 2.14.40 PM1) this first patch demonstrates basic granular synthesis using the poly~ object and metro. “note” is prepended to the message sent to poly~ as it is typically used for polyphony.

 

 

 


Screen Shot 2018-02-27 at 2.19.10 PMthe sine grain abstraction is a random pitch sine wave generation with a raised cosine envelope. to turn a cosine into an envelope/window, one must invert it, cut the amplitude by 1/2 and shift it up by 1/2 so that it starts at 0, goes up to 1, and ends at zero. this inverted and shifted cosine is known as a raised cosine window.

 

 

 

 


Screen Shot 2018-02-27 at 2.55.37 PM2) this example adds 2 operator FM synthesis to a granular framework. the external patch is almost identical to the previous example except that more parameters are packed together and sent to the poly~ object.

 

 

 

 

 

Screen Shot 2018-02-27 at 2.59.44 PMthe “grain” abstraction is similar to the previous example except that for each grain a random ratio and index is generated and given to a small fm2op abstraction (below).

Screen Shot 2018-02-27 at 3.01.59 PM

 

 

 

 

 

 

 

 


 

Screen Shot 2018-02-27 at 3.44.30 PMScreen Shot 2018-02-27 at 3.46.57 PM3) the third example is a granular harmonic oscillator in which each grain generates a random harmonic of the base pitch.

 

 

 

 

The abstraction is almost identical to the original sine example except that an additional random object is added to create the harmonic frequency multiplier.

 

 

 

 

 


 

Screen Shot 2018-02-27 at 3.52.52 PMScreen Shot 2018-02-27 at 3.54.14 PM4) The final example is a granular sound file player which randomizes the playback start position. A slider in the main patch is used to set the original start position. The sound needs to be loaded with the “replace” message before this patch will work.

 

 

 

The playback abstraction requires a little more logic to derive the playback start, end and time from the pitch and position parameters in the main patch.

MUS271A (Max w7) – sampling

These patches should get you started with sampling. Not all techniques are shown in my examples, and many things are easier if you use the groove~ object. Also, only a few of my examples are shown in this blog entry.

Download the patches here: 05-sampling


Screen Shot 2018-02-28 at 9.08.39 AM

 

1) This first example shows manual playback of a sample by moving a slider to move through the samples. Your slider movement is smoothed out using the line~ object.

 

 


Screen Shot 2018-02-28 at 9.15.47 AM

2) In this example, line~ is again used to playback the sample, with the speed of playback controlled by setting the beginning and end playback points and the amount of time to get to the end. Reverse playback is easily achieved this way.
Also, sin and cos are used for crossfading between 2 samples.

 

 


Screen Shot 2018-02-28 at 9.32.56 AM

3) An unrefined patch for stutter playback. The startms number box controls the playback position in the buffer~. The size of the stutter is controlled by the metro time. Pitch shifting is controlled by speed ratio.

 

Screen Shot 2018-02-28 at 9.47.20 AM

 

 

A slightly more refined stutter playback patch using trapezoid~ to remove clicks on the beginning and end of each segment. Also, pitch can be controlled by MIDI note number with 69 representing normal playback speed.

 


 

Screen Shot 2018-02-28 at 9.50.50 AM

 

 

4) A sound file player which uses the folder object to open all sound files in a folder, and a popup menu to list and select them. A coll object
could also be used to organize the files.

 

 


Screen Shot 2018-02-28 at 9.56.47 AM

5) OLA (overlap add) sound file playback. This plays the sound in many overlapping segments, with each segment enveloped by a raised cosine window/envelope. Position and pitch can be controlled independently so that time stretching and pitch shifting are possible. A random offset can be added to each segment to avoid repetition.

 

 

 

 

delay impulse responses

Impulse Responses from various delay lines, in various states of repair –


Screen Shot 2018-02-12 at 11.11.18 AM
Gibson GA-4RE (Telray Adineko echo). This circuit has considerable leakage of dry signal. You can hear that as the first impulse. The first “dark” impulse can be considered the impulse response of the delay. Also, there is no erase “head”. The brush simply writes over the charge on each rotation of the disk. The repeated echo isn’t due to feedback, but progressive erasure. Use the entire impulse response for an accurate emulation.

download impulse


Echoplex  (Original – pre “EP-1″ Serial 709). A tiny bit of dry signal leakage. The tape impulse response shows up at about 360 ms. I am not sure why there is a sine sweep artifact in this IR (after the impulse). Possibly because the tape transport is so unstable, or perhaps interaction with the bias oscillator?

download impulse


Screen Shot 2018-02-12 at 11.05.29 AM
Roland Space Echo RE-201. Much cleaner compared to the previous two devices. No way to turn the dry signal off (perhaps my Space Echo is in need of repair?).

UPDATED – New measurement from the PA input to get just the tape signal (no dry)

download impulse


Screen Shot 2018-02-12 at 11.06.41 AMDeltaLab Effectron. A very clever digital delay which measures differences between successive samples. An almost flat response which tilts slightly upward.

download impulse


Bright Analog Delay Pedal. A modern CCD (charge-coupled device) delay. There is a bit of ripple in the passband (could be a Chebyshev I filter?) which caused a noticeable resonance after multiple repeats.

download impulse


Screen Shot 2018-02-12 at 2.18.26 PM
Dark Analog Delay Pedal. Another CCD delay. This one has a rounder, smoother filter response (possibly Bessel?), so no coloration after multiple repeats. Sharp rolloff at 2k for CCD aliasing rejection. You can see the signal leakage as a -60dB signal above 3k.

download impulse


The sine sweep and golay code methods of impulse response measurement used are from Edgar Behrdahl & Julius O Smith’s Transfer Function Measurement Toolbox


A PD echo patch with convolution in the feedback

download this: emuplex

Screen Shot 2018-02-07 at 11.32.54 AM

Mus174B – Assignment 2

mus 174b – assignment 2

record 5-10 tracks: 2+ solo, 3+ backing – 2:30 to 6 minutes – must be recorded with microphones
– double track (or more) the solo instrument or voice
– divide tracks into 2-4 functional groups (these groups should be named, and make sense)
– use compression on one or more groups or tracks
– use gating to tighten up a track
– use either key gating or a gated delay/reverb effect
– use delay, phase shift, chorus or flange to accentuate a foreground track
– use pitch shifting or distortion to thicken a track
– reverb only on individual tracks
– save the groups as individual recordings after effects (stems)
– hand in documentation describing your mix decisions

due tuesday week 8 – 2-27-18
extra point for presenting on 2-27

groups

john d’agostini – crystal jiao – kostyantyn chumakov
yidai li – cory bahn – forest reid
grant hovander – francis galang – salvador zamora
caleb hess – christopher loree – cordane richardson
camden greenwood – william carlisle – matthew rice
chi zhang – raymond lim – jorge jiron villarreal
tracy levick – daniela chaparro – gregory farley
chloe bari – kenroe ang

MUS271A (Max w2 & 3) – oscillators – additive synthesis

In the next few classes we will look at the fundamentals of synthesis. In class we will actually build more extensive patches than are covered here. In this class we will look at synthesis of classic waveforms, sine, sawtooth (aka ramp), square (also pulse, aka rectangle), and triangle. These waveforms are often used in synthesis not only because they are simple to create with analog circuitry, but also because they share characteristics with acoustic instruments. All waveforms have harmonics with decaying amplitude as you go up the harmonic series, similar to most acoustic instruments. The square and triangle waves have only odd partials, similar to a pipe with one end closed. The sawtooth wave has all partials, similar to a pipe with both ends open, or a string. The sine wave has only one partial, so can easily be used to create complex tones by aggregation (additive synthesis). All of these patches can be downloaded here.

Screen Shot 2018-04-09 at 2.13.23 PM1) Basic Waveforms

All of these waveforms are available in Max as internal objects. The following simple patch shows all of them (saw~, tri~, rect~ and cycle~). Each has a frequency input and a sync (phase reset input). rect~ and tri~ have duty cycle inputs, that reshape the waveform by moving the center of the wave shape. Listen to the combination of these waveforms by clicking on the toggle buttons.


Screen Shot 2018-04-09 at 5.41.58 PM2) Duty cycle modulation

This next patch shows the effect of changing the duty cycle in the rect~ (pulse/square wave) and tri~ objects. You will notice that the tone gets brighter when the duty cycle moves away from .5 and toward either 0 or 1.0. A pulse wave with a very small duty cycle (either almost 0.0 or almost 1.0) will have nearly a flat spectrum with little rolloff. Both the pulse wave and triangle wave cancel all even partials when the duty cycle is 0.5. You can see the  odd partials diminish by moving from .55 to .50. Modulating the duty cycle with a slow sine wave is a good way to give the sound timbral variation.


Screen Shot 2018-04-09 at 6.00.36 PM3) Detuning, more specifically – SUPERSAW!!

Another way to get timbral modulation is to group several oscillators of the same type and detune them slightly. This will cause the oscillators to go in and out of tune at the rate of the difference between the two frequencies. That is, if the oscillators are separated by 1 Hz, you will hear them go in and out of tune once a second. If you use waveforms which have no odd harmonics (sine, square and triangle), you will have a moment when all harmonics cancel. For this reason, detuning is usually done with sawtooth waveforms or more than 2 of the other waveforms. In this example, I am using 3 sawtooth waveforms. The pow functions are calculating the detuning. This patch is also known as a supersaw, and adding more detuned sawtooth oscillators can make it more complex.


 

Screen Shot 2018-04-09 at 6.18.36 PM4) Hard Sync – phase resetting.

All of the oscillators in Max have “sync” inputs which reset the phase to the beginning of the cycle. If you use the sync input and the frequency input, the waveform will be reshaped by having a frequency higher than the sync frequency. That is, a frequency of 1.5 Hz will complete 1.5 cycles per second, and a sync frequency of 1 Hz will cause the waveform to repeat every second. The resultant waveform is 1.5 cycles of the normal waveform repeated every second. This interrupted waveform will have a sharp discontinuity and many more high harmonics. This synthesis technique is called hard sync. One interesting aspect of this is that whenever the frequency input is an integer multiple of the sync frequency, you will get a harmonic of the sync frequency.

A couple of notes on this patch. The upper display represents the phase of the oscillator, the middle display is the resultant waveform and the bottom display is a sonogram. There is a bit of ugly logic in the middle of the patch to cause the sawtooth to “wrap” or to keep an amplified phasor~ within the range of 0.0 to 1.0. Max doesn’t have a wrap~ object like pd, so I rescaled the input and output to phasewrap~ to get the same behavior. An experienced Max programmer is welcome to tell me of a better way to do this :).


5) Additive synthesis

Additive synthesis is the technique of adding multiple waveforms which are at the harmonic frequencies of a fundamental frequency. The partials are typically sine waves (which have no harmonics themselves). The harmonic ratios can be easily manipulated, as can the amplitude of each partial. All of these numbers can and usually do change over the duration of a note. This amount of detail allows one to specify an exact timbre, but also requires a large amount of data (typically a separate amplitude and pitch trajectory for 32 or more partials. For this reason, additive synthesis is not often used, as it takes a lot of exacting work to get a good sounding result. Current common uses of additive synthesis are pitch shifting and autotune.

Screen Shot 2018-04-09 at 6.43.59 PM5a) The tone wheel organ. One common example of additive synthesis is the tone wheel organ. The amplitude of each partial is controlled by drawbars. Here is a patch which simulates the drawbar settings for a simple tone wheel organ. Only 8 sine wave oscillators are used, and an ADSR envelope generation object is used to shape the note. This patch is designed to be played by a MIDI keyboard, but the note can be set (the number box above sig~) and a 50ms note played with the bang above delay 50cycle~ 4 provides a little vibrato. The amplitude is not normalized in this patch, so the output volume needs to be turned down to avoid distortion.

Screen Shot 2018-04-09 at 7.03.21 PM5b) Going down the rabbit hole. This patch demonstrates simple additive synthesis, but also demonstrates the need for more detail. However, creating many oscillators and amplitude controls can be tedious. In this next example I am using the poly~ object to create any number of harmonics. poly~ uses an abstraction (a separate patch) and creates many copies of it. Each copied patch can find out which copy it is from the object thispoly~. For additive synthesis, that number is used for the partial number and is multiplied by the fundamental frequency. There is also a amplitude adjustment which mutes the voice when the frequency is above 20000 Hz. This is a crude method to stop aliasing.

On the right side of the abstraction is a sel object which computes the amplitude for each harmonic. In this example, I am creating various simple waveforms. From left to right: sine, pulse-train, sawtooth and square. You can see under each sel output is logic which determines the amplitude of each partial based on the thispoly~ number. These amplitudes are sent out the out~ 2 outlet to be summed to an overall amplitude.

Screen Shot 2018-04-09 at 6.59.46 PMThe external patch is simple in comparison. poly~ creates 64 patches for partials, a radio button selects the waveform, and the left output of poly (the summed sine waves) is divided by the summed partial amplitudes so that the resultant waveform has an amplitude of 1.0.

oscbank~ can alternatively be used for additive synthesis, but independent control of each partial is more difficult.

mus 174b – assignment 1

1) record new material, 6-12 tracks:  between 2 and 4 minutes
2) make several inaudible edits
3) one or more of the tracks should be vocal
4) the rest of the tracks can be computer or electronic (synths, drum machine, pd, max/msp, looped samples, noise, etc.). no premixed backing tracks
5) all electronic tracks should have track effects (plugins) to give them unique identity using eq or reverb
6) create 2 different mixes which gives a different sense of foreground, width and depth
7) create width with panning
8) establish foreground instruments with volume differences and eq
9) create width and depth with reverb/mic distance
10) separate the tracks into 3 or more groups, route the groups into 3 or more aux input tracks, mix aux tracks for final mix
11) apply fade-in and fade-out to final stereo mixes
12) leave session and mix files on class disk (174B folder, project name with your last names)

present in class on 2-1-18 or 2-6-18 (thurs. wk4, tues. wk5)

groups

Cory Jonathan Banh – Francis Kyle Galang – Matthew Harrison Rice
Christopher Patrick Loree – Jorge Alberto Jiron Villarreal – William Joseph-Glen Carlisle
Raymond S Lim – Daniela Andrea Chaparro – Gregory Tazmond Farley
Chloe Jessica Bari – Kenroe Ervin Ang – John Anthony D’Agostini
Yidai Li – Grant Parker Hovander – Kostyantyn Chumakov
Caleb Michael Hess – James Forest Reid – Camden Robert Greenwood
Chi Zhang – Tracy Nicole Levick – Salvador Zamora
Jacob Michael Ugalde – Crystal Jiao – Cordane Omari Richardson

MUS271A (Max w1) – starting point

The focus in 271A will be sound generation with Max/MSP. In the first two weeks I will go over any concepts people are unfamiliar with, so there will be less standard material. However, here are some patches we will use as a jumping off point. The patches can be downloaded here 00-maxbasics


 

Screen Shot 2018-03-15 at 3.10.30 PMHere is a patch showing a square -saw oscillator as an abstraction (a patch which shows up as an object within Max). Frequency is converted from MIDI note number with mtof, The toggle button selects the square or saw wave (this is not a true saw wave). live.gain~ is used as an output volume control and meter. ezdac~ is used to send the audio to the computer sound output. Finally scope~ is used to display the waveform. We will look at how to modify the scope~ display using the info panel (clicking the “i” in the right column.Screen Shot 2018-03-15 at 3.11.49 PM

The 02-squaresaw patch makes up the abstraction. The inlets and outlet are labelled “1”, “2” on the top and “1” on the bottom. Both signals and messages can pass through these ports. The rest of the patch is a simple combination of a rect~ generator and a cycle~ generator (making square and sine waves).

 

 

 


Screen Shot 2018-03-15 at 3.24.12 PMThis next patch shows the many MIDI messages and the objects which receive them. The simplest is probably bendin which receives pitch bend information. Pitch bend has a range from -64 to 63, with 0 in the center. I am dividing the lower range by 64 and the upper range by 63 so that bend up and down are symmetrical.

ctlin receives all other MIDI controllers (knobs, switches, sliders, pedals). The value (0-127) comes out the left outlet, and reflects the control parameter value. The center outlet is the controller number (also 0-127). Finally the right outlet is the MIDI channel. This allows a keyboard or other MIDI device to target 16 different MIDI destinations (typically different synthesizers).

notein receives both note down and note up messages. The left outlet is the note number (0-127, C4 = 60), the center outlet is the velocity or pressure (0-127), and again the right outlet is the MIDI channel. A velocity of 0 indicates a note up or release.

In this patch I am using poly to pack a voice number with the MIDI note and velocity. This voice number is used by route to direct the note and velocity to one of three sound generators. The outputs of the sound generators are all sent to “sum” with send~ and receive~.

Another patch in the class one zip archive shows how to use the computer keyboard to generate “note” messages.


 

Screen Shot 2018-03-15 at 3.47.26 PMThis patch is a simple use of metro. A BPM value is converted into milliseconds per beat by dividing 60000 by the BPM. metro then sends “bang” messages to two messages which control the amplitude and frequency of a sine wave (cycle~), which gives a sort of kick drum sound.

 

 


Screen Shot 2018-03-15 at 3.52.13 PMThis patch uses qlist as a sequencer.It will be explained more throughly in class. When metro is started, the time is incremented 10 ms at a time by counter. This time is used whenever one of the note messages (56, 55, 59, 58) is clicked. This information is collated into an append message and recorded by the qlist. A “bang” message causes the qlist to replay the note messages and send them to the simple synthesizer voice. qlist restarts playback after finishing by triggering another “bang” at the end.