This report is to explain the process of how the synthesisers
have been designed and looking at the way I approached the audio demonstration.
Code Snippets used from previous labs:
ADSR Envelope Lab 1 1
Guts for the FM Synth 2
Guts for the Subtractive Synth 3
These snippets were made by me but produced from the guidance
of the documentation in the lab scripts.
synth was designed to use two oscillators with different frequencies to create
depth in the sound. The Synth uses a Low Pass filter, High Pass and VCF. The
synth output audio through the VCF then the High Pass filter then the Low Pass
filter. I designed the synth with an
ADSR filter which can be modified by going into the patch ADSR or by changing
the values in the qlist. The synth a play button to play the note with the
envelope, and a play with no decay button which plays the synth with no decay.
This is useful for finding the sound that you want the synth to produce.
Synth has been designed with 1 main oscillator and 3 modulating oscillators.
The modulating oscillators have ratios which are predefined. However, they can
be manually changed in qlist or by going into the “fm_synth” patch. In addition, each oscillator has an individual
ADSR (attack, decay, sustain, release) envelope to produce different developing
added 5 different preset sounds to the patch:
Piano with no pedal
Brass instrument with short release
these preset sounds have a custom ADSR envelope with both each individual
modulator envelope changing and the main envelope being changed.
Synth outputs its voice through the panning module which then goes through to
the master volume to control the main volume of the synthesiser. I originally
had a reverb module which is left in however I disconnected it from the output
routing because it didn’t add anything to the synth’s feel.
making my audio demonstration I was heavily inspired by the Netflix Series
Stranger Things, the intro to which uses a synthesiser. I decided to take the approach
of a musical sound scape which experiments through some of the different sounds
the synths can create.
demonstration starts off with the FM synth on the “developing pad” preset
playing notes and allowing the sound to expand through space. On the final note,
the subtractive synthesiser starts playing an arpeggiated pattern slowly
increasing in volume as the FM synth fades away. It then ends by changing
sounds and going to the subtractive synthesiser playing the different sound.
This sound was produced by changing the LFO amount and the filters. The section
played on the subtractive synthesiser is ended by the FM synthesiser playing
its developing pad sound. The piece then moves on to play the FM synthesiser on
a repeating pattern changing voice each time. The piece uses panning to move
the sounds around the listeners head.
1 Advanced: ADSR-Envelope. Available: https://www.elec.york.ac.uk/internal_web/meng/yr1/modules/Audio_Technology/02_additive_synthesis/06_ADSR.html
2 FM Synthesis in PD. Available: https://www.elec.york.ac.uk/internal_web/meng/yr1/modules/Audio_Technology/04_FM_synthesis/01_contents.html
3 Subtractive Synthesis in PD. Available :
4 Frequency Modulation. Available: http://write.flossmanuals.net/pure-data/frequency-modulation/