Creating an Additive Synthesiser in Synthmaker
Additive Synthesiser
The following, is a quick post on the methods
used to create an additive synthesizer within the software program Synthmaker.
This software was available for free with issues of computer music magazine,the software goes by a different name nowadays but any modular synthesiser program has the same principles described here.
This software is similar to programs such as reactor so many of the principles can be applied to whatever synthesiser building program you may be using.
The report will highlight the methods used to create the synth, the intentions behind creating the synth and how successful the end product was.
This software was available for free with issues of computer music magazine,the software goes by a different name nowadays but any modular synthesiser program has the same principles described here.
This software is similar to programs such as reactor so many of the principles can be applied to whatever synthesiser building program you may be using.
The report will highlight the methods used to create the synth, the intentions behind creating the synth and how successful the end product was.
The principles of additive synthesis are fairly simple and rely on basic sine waves to provide the basis for the sounds which will be created by the synthesizer.
The basic premise of additive synthesis, is that a waveform can be described in terms of the frequencies and amplitudes of those frequencies contained within the waveform.
This means that a certain amount of sine waves can be blended together at particular frequencies and amplitudes can be used to create different waveforms such as square or saw tooth waveforms.
The character of the waveform, will be dependent on the harmonic intervals determined from the fundamental frequency.
A very basic form of additive synthesis is the
The
first stage, involves using a combination of sine waves to produce a
fundamental frequency and the harmonic information that the fundamental would
produce in a real world instrument. At least 9 individual sine waves would be
employed within the additive synth to create some harmonics at differing
amplitudes to provide some character to the basic synth sound.
The basic additive synth was used as the blueprint for the synth but some extra harmonics would be added to give more harmonic depth to the sound. An 8th and 9th harmonic were added into the additive module, adding some further high frequency content to the overall tone.
The harmonic values of 8 and 9 were typed into the float integers and amplitude values of 0.2 were set, initially, for both harmonics.
The amplitude values of each harmonic note could be altered individually or via a controller which could provide increased possibilities to alter the sound in real time. The sounds at this point would vary from high frequency tones to low bass tones depending on the amplitude values set for each harmonic.
There are still many factors that need further consideration if the additive synthesizer is going to have more variation of sounds.
The basic additive synth was used as the blueprint for the synth but some extra harmonics would be added to give more harmonic depth to the sound. An 8th and 9th harmonic were added into the additive module, adding some further high frequency content to the overall tone.
The harmonic values of 8 and 9 were typed into the float integers and amplitude values of 0.2 were set, initially, for both harmonics.
The amplitude values of each harmonic note could be altered individually or via a controller which could provide increased possibilities to alter the sound in real time. The sounds at this point would vary from high frequency tones to low bass tones depending on the amplitude values set for each harmonic.
There are still many factors that need further consideration if the additive synthesizer is going to have more variation of sounds.
Time
and how a sound changes over time is a key factor in a sound being interesting
to listen to.
In a stringed instrument, the natural inclination of the sound is to be bright at the initial attack of the sound but over time, the higher frequencies fade away more quickly than the lower frequencies.
This can be replicated within the synth by controlling the low and high frequency harmonics separately, using an envelope.
This was done by creating a separate output for the 1st to 5th harmonics from the additive and then creating a separate output for the 6th to 9th harmonics from the additive module.
In a stringed instrument, the natural inclination of the sound is to be bright at the initial attack of the sound but over time, the higher frequencies fade away more quickly than the lower frequencies.
This can be replicated within the synth by controlling the low and high frequency harmonics separately, using an envelope.
This was done by creating a separate output for the 1st to 5th harmonics from the additive and then creating a separate output for the 6th to 9th harmonics from the additive module.
These separate outputs were then connected
to an ADSR envelope module separately
Doing
this , allowed some control over how the harmonics would behave and the low and
high frequency content could be controlled to react differently over time from
each other.The intention, is to simulate the behavior of a stringed instrument where the high frequency content will fade more quickly over time than the low frequency content.
This is a starting point for the synthesizer but more interesting results may be achieved by adding some control to the individual harmonic components themselves.
The ADSR envelope was set to a particular value and then made into a module in order to keep the internal synthesizer components in order. Each individual harmonic or particle of the additive synthesizer would have a separate slider control which would determine the amplitude value of each separate harmonic, therefore, allowing a greater degree of control over the overall sound.
This was done by connecting a vertical slider to each harmonic’s amplitude value whereby each slider could then be controlled on the synthesizer front panel.
The intention was to provide a
similar idea to the drawbar system on a Hammond
Some modifications were also made inside some of the vertical sliders where the value scale of the vertical slider would be increased from 0 to 1 up to 0 to 10.
This was designed to give extended control to the amplitude values of each harmonic with increased possibilities in changing the sound of the plug in.
Some modifications were also made inside some of the vertical sliders where the value scale of the vertical slider would be increased from 0 to 1 up to 0 to 10.
This was designed to give extended control to the amplitude values of each harmonic with increased possibilities in changing the sound of the plug in.
As part of the process, each
vertical slider’s scale would be altered differently in order to give a
specific character to each harmonic.
The slider would then be given a label/name describing the characteristic of the sound which would then be clear on the front panel, giving the user a preset description of each vertical slider on the front panel.
The intention was to provide a wide range of sounds through adding different harmonic components at varying amplitudes.
The synthesizer would be routed in two different sections. One section would feature the higher harmonics whilst the second section concentrated on the low to mid range content.
Each section also had its own envelope, allowing control over the sustain of the frequency content within each section. This could enable the user to tailor the envelope controls of each section whereby the higher frequencies tail off quickly in a manner evoking the characteristics of stringed instruments where much of the high frequency information exists in the attack portion of the envelope rather than in the release of the note.
The slider would then be given a label/name describing the characteristic of the sound which would then be clear on the front panel, giving the user a preset description of each vertical slider on the front panel.
The intention was to provide a wide range of sounds through adding different harmonic components at varying amplitudes.
The synthesizer would be routed in two different sections. One section would feature the higher harmonics whilst the second section concentrated on the low to mid range content.
Each section also had its own envelope, allowing control over the sustain of the frequency content within each section. This could enable the user to tailor the envelope controls of each section whereby the higher frequencies tail off quickly in a manner evoking the characteristics of stringed instruments where much of the high frequency information exists in the attack portion of the envelope rather than in the release of the note.
After the additive and ADSR envelopes, a further reverb module was added
to give a sense of space to the basic sounds being produced from the harmonics.
The reverb unit was customized from an existing unit but new knobs and their
values were applied to the float integers to create different values for the
room size, width and effect mix. These values were set by drilling into the
individual knob controls and setting parameter values.
This allowed for some
fairly subtle reverb settings which would provide some depth to the overall
synthesizer sound.
Volume and
Strength Controls
After the reverb module, the volume
control module was added which would produce a non linear behaviors for the
action of the volume and strength control knobs connected to the bender module
and situated on the front panel as volume and strength controls.
The volume and strength controls were connected to two float integers which would then connect to the bender module, determining the non linear control of the volume and strength controls which would also be visually represented by a level meter.
The volume and strength parameters were also adjusted by drilling into each of these respective knob controls and setting new levels for the minimum and maximum settings.
The volume and strength controls were connected to two float integers which would then connect to the bender module, determining the non linear control of the volume and strength controls which would also be visually represented by a level meter.
The volume and strength parameters were also adjusted by drilling into each of these respective knob controls and setting new levels for the minimum and maximum settings.
To provide some quick settings for
users, a preset manager was integrated onto the front panel and some quick
preset files and sounds were created and appropriately named for quick use.
Four presets were named,Rhodes , Rhodes reverb, steel drums and organ. The vertical sliders within the
additive module were untidy with a clumsy layout so these were all converted
into modules, attached to the float integers, which were also converted to
modules, and connected to the harmonic components.
Four presets were named,
Harmonic sliders
within the additive tidied by converting into modules
The final
internal working of the synthesizer can be seen in the screen shot below
sampledelicsounds.com
http://www.sampleism.com/papasstgermain/downtempochilltraxvol1?sk=kt
