Parsec Part 2: Sound Generators

Last week I gave a brief overview of Propellerhead’s rack extension instrument Parsec and discussed the concept of additive synthesis – the addition of multiple sine waves together to create complex harmonic content.  This week I am going to dive into Parsec’s two signal generators.  Each generator can produce up to 512 sine waves, which are then sent through a low pass/high shelf filter with adjustable slope and variable cut off frequency.  Both generators have a waveform/signal selector with a modulation knob, variable octave and tuning knobs, as well as a keyboard follow parameter.

The signal is then passed through the dual modifier section (in series) before reaching a two-channel crossfade.  After this, the combined signals pass through an amplitude envelope, Parsec’s effects sections and then a final gain stage.

Waveform/Signal Selector

Saw -> Square

The modulator sweeps between a sawtooth wave (0%) and a square wave (100%).

Pulse

The pulse selection consists of two alternating pulses that contain all harmonic overtones.  The modulation knob alters the phase between the two pulses, causing phase cancellation for certain overtone frequencies, which results in a more complex timbre.

Frequency Modulation (FM)

This generator works on the principal of frequency modulation.  When the modulator is set to 0, the generator produces a sine wave (operator).  As the modulation knob is increased, the frequency of modulating sine wave increases, altering the operator wave and increasing the harmonic content above the fundamental.

Dual Saw

This selection generates two sawtooth waves at the same frequency.  When the modulator is increased, the second sawtooth wave's pitch is detuned upwards.  At 100%, the second wave is a full octave above the first.

String

This generator simulates the harmonic content of a vibrating string.  As the modulator knob increases, the harmonics are shifted upwards and the spaces between them are "stretched".  Above 50%, the sound becomes more and more inharmonic.

Sparse

This generator operates on the principal of wavetable synthesis, consisting of eight different harmonic overtone series.  The modulation knob alters the position within the wavetable and allows for a smooth transition between the individual overtone series.  There are harmonic and inharmonic versions of this generator.

Ratio

This generator creates hundreds of sine waves at ratio intervals to simulate partial harmonic overtones.  The modulation knob changes the ratio between a pure sine wave (1:1) and sine waves at octave intervals (2:1).  

Noise

This generator produces a range of noise, the color of which is altered by the modulation (bandwidth) knob.  When initialized, this generator produces a pulse wave with noise-modulated particles. As the modulation knob is increased, the bandwidths of each pulse harmonic increases until you get white noise (100%).

FM Noise

The FM Noise generator uses frequency modulation of partials with noise, resulting in a similar, but "sharper"noise than the simple noise generator.

Perc 1 & 2

These two generators create variable frequency content that are useful for creating electronic and metallic percussion sounds.

Thanks for reading.  Stay tuned for the next post where I will discuss Parsec's modifier section.

Parsec Part 1: Spectral Synthesis and Overview

In this post I would like to talk about a rack extension for Reason.  As you may remember from my previous post, rack extensions are the plug-in format for Reason, offering additional instruments, effects, signal processing and audio/control-voltage utilities.

Today I would like to talk about one of my favorite Rack Extension instruments: 

Parsec

So, first of all... what the heck is a "spectral synthesizer"?

Parsec uses a concept called additive synthesis to create complex waveforms.  This is a form of synthesis where sounds are created by adding many sine waves at varying phases, amplitudes and periods.  This creates richly harmonic (or inharmonic depending on your taste) content above the fundamental.  This differs from most synthesizers which use subtractive synthesis, which uses filters to subtract harmonic content produced from wave forms that may already be rich in harmonic content.  Additive synthesis offers a much more precise method for producing a specific sound or creating complex timbres. 

Parsec's Components

(1) Patch Selector

Allows you to browse, load and save patches for the instrument.  Parsec comes loaded with patches ranging from basses, leads and pads, to "textures" and percussive sounds.  There are patches available for purchase from Propellerhead and 3rd-Party developers.

(2) Global Output Parameters

This section includes the overall output control and the "spread" knob which adjusts the width of the stereo field

(3) Sound Engine A/(5) Sound Engine B

The sound engine is the core of Parsec's additive synthesis.  This section includes two separate sound generators, each with their own modulation and tuning parameters, filter, and two modifiers each.

(4) MIDI Note LED

Indicates note gate activity.

(6) Modulation sources and built-in Effects

The modulation section includes two individual LFO's, two modulation envelopes (one with delay, hold and loop selection) and an amplitude envelope.  This section also includes built in delay and reverb as well as a "balance" knob which mixes the two sound engine signals together.

(7) Global performance controls

This section includes voice range selection (monophonic to 24 voices), modulation wheel and a pitch bend wheel.

(8) Modulation Bus Matrix

The modulation bus matrix works similar to the one in Thor, with selectable modulation sources, destinations, corresponding amounts and scaling sources.

(9) Global "play" controls

The final section controls global parameters like keyboard mode (polyphonic vs. monophonic retrig/legato) and Portamento settings.

The Rear

The rear of the unit has several connections available for signal routing.  Control Voltage routing inputs include sequencing controls: Gate, CV (note/pitch), Pitch bend and Mod Wheel.  You can also modulate amplitude level, LFO 2's rate and the balance knob directly or input a control voltage signal into CV inputs 1 and 2 which can be routed to any parameter using the modulation bus matrix on the front.  Each engine's modulation controls can also be modulated with control voltage signals.

You may also notice an audio input about the stereo output connection.  This allows you to alter any audio signal with Parsec's additive synthesis engines for an incredible range of unique sounds.

I hope you enjoyed this post.  Tune in next week when I will go more in depth about the sound engine sections and how Parsec uses additive synthesis to create sound.

Reason: Rack Extensions

ReasonExperts.com

Today I am going to talk about Rack Extensions from Propellorhead.  For those of you who are unfamiliar with Reason or the concept of "Rack Extensions", Propellorhead has a unique virtual "rack" of instruments, processors, utilities and effects.  Reason comes with 2 percussion instruments, 3 synthesizers, a virtual instrument modeler, a .Rex loop player and two samplers.  In addition, Reason comes with over 20 spectral/dynamics processors and effects, plus two mixers, control voltage utilities, an arpeggiator and a monophonic pattern sequencer. 

Now I know that sounds like a lot of toys to play with - and to be honest, you can absolutely get by with a "rack" of just these - but sometimes you just need a little extra something.  Or maybe you just can't quite get a certain sound right.  Maybe you love the workflow in Reason (I know I do...) but you want access to integrated third-party instruments that you would normal run as a VST or a plug-in...

Thats where Rack Extensions come in.  After their inception in Reason 6.5, the available rack extensions were very limited, and mainly produced/released by Propellorhead - which honestly made it feel like buying expansion packs.  But as time went on, reputable developers began producing their popular plug-ins in the Rack Extension format.  Examples include:

Rob Papen

• SubBoom Bass
• Predator 
• Punch
• RP Verb and RP Distort

Softube

• TSAR-1/1R Reverbs
• FET Compressor
• Trident A-Range EQ
• Valley People Dyna-Mite 
• Saturation Knob
• Spring Reverb and Tube 

McDSP

• C670 Compressor
• FRG Compressor
• Moo Tube Compressor

KiloHearts

• Faturator
• kHs ONE

For the most part, these rack extensions are indistinguishable from their VST/RTAS/AU counterparts (aside from Rob Papen who seems to like change) in both appearance and functionality.  So I suppose if you already have these plug-ins in other formats, it wouldn't make much sense to purchase the Rack Extension version (unless you're like me and your workflow is infinitely better in Reason compared to other DAWs).  But for those of you who like Reason, and use it as your primary DAW, I highly recommend buying into the Rack Extension market.  

Here are some Rack Extensions that I own and recommend:

Parsec Spectral Synthesizer (Propellorhead)

Ozone Maximizer (iZotope)

Mercury Polyphonic Arpeggiator (Quadelectra)

Thor Polysonic Synthesizer Part 4: Modulation Bus Matrix and Step Sequencer

In this post I am going to look at two components that a lot of people I talk to seem to find daunting and intimidating.  I will admit that I rarely (if ever) use the step sequencer "successfully" and The Matrix takes a bit of experimenting with in order for you to get exactly what you want.  But they are invaluable tools that can drastically alter the character and behavior of your Thor patch.  As I mentioned in my first post, the best way to learn how to use Thor is to jump in with two feet and play around with it.  And you can't experiment without the Mad Doctor modulation bus matrix:

Modulation Bus Matrix

Now I know this looks a bit crazy and a bit too close to an Excel spreadsheet for ANYONE's comfort.  But I assure you, it is MUCH better than playing the 97 Flight Simulator easter egg.  Beginning with the left-most section we see four columns with seven rows.  Each row is an individual modulation path beginning with the Source.  From this drop-down menu, you can select an ungodly amount of modulation sources including the aforementioned LFO's and Envelopes.  The next column is the amount by which your modulation source will alter a specific parameter which is selected in a similar drop-down menu in the "--> Destination" column.  The last two columns allow you to scale the modulation amount by another modulation source at another specified amount.  For example:

Here I am using LFO 2 to modulate Oscillator 3's Detune Amount, by an amount of 33%.  The 33% is scaled by the Modulation Envelope by an amount of 19%.

That is literally the gist of the entire modulation bus matrix.  I swear.  There are two more sections but the only differences are the additional destination for modulation (in the upper right section) and the additional modulation scaler (in the lower right section).

Step Sequencer

The step sequencer does exactly what you think it should do: it sends note data to the three sound generators which then route signal through Thor as if the information was coming from the sequencer window or a MIDI keyboard.

This section offers a 16-step gate sequence with adjustable synchronized/unsynchronized rate.  Each step can be turned on/off with the corresponding LED square above the step number.  The number of steps can be adjusted with the "Steps" rotary in the bottom right corner.

This sequence is engaged with the "Run" button.  It can be set to play repeatedly, once ("1 shot") or step by step ("step").  The sequence can also be set to to play forwards, in reverse, forward<-->reverse with steps 1 & 16 repeated ("Pendulum 1"), forward<-->reverse without steps 1 & 16 repeating or in a random order.

The rotaries above each step affect the parameter that is selected by the Edit rotary.  These allow you to individually change each step's pitch, velocity, gate length, and note duration.  The final two curve options can be used to send amount values to any parameter in Thor via the Modulation Bus Matrix.  

Finally, if it gets way too hectic, out of control and you need to calm the god of thunder, you can always hit the Reset button in the upper right corner to initialize the step sequencer.

Thanks again for reading.  Stay tuned for the last edition on Thor's built-in delay and chorus modules.

Thor Polysonic Synthesizer Part 3: Modulation Sources

Last week we talked about the sound generation and subtractive filtering components within the Thor Polysonic Synthesizer.  With knowledge of these components you can create a wealth of unique sounds.  But no matter how hard you try, these sounds won't seem as "alive" or unique without the use of some sort of modulation.

Thor offers two types of modulation: LFO's and Envelopes.  

LFO's

LFO's - or Low Frequency Oscillators - are similar to oscillators that you would use to create musical pitches however, LFO's operate at a slower frequency (0.07 - 99.6 Hz in Thor at 20 BPM).  These are the oscillator waveforms available in Thor's LFO 1 and LFO 2:

These include Sin, Sawtooth, Square, Triangle, both rigid and smooth Sample and Hold (i.e. Random), and exponential waveforms as well as both stepped and stepped-ramp waveforms (with multiple step-counts per cycle).  Using the modulation bus matrix (which I will discuss later), you can modulate almost any parameter within Thor with any of these waveforms at a set rate and to an adjustable amount.

Thor offers two LFO sources (aptly named, LFO 1 and LFO 2) for modulation.  Both LFO's offer independent waveform selection, tempo sync, key sync (restarting the LFO's position when a note is played) as well as rate and delay rotaries that run independent from one another.  LFO 1 has the additional parameter called "keyboard follow" which determines how the position of the notes played effects the rate parameter.  As the follow parameter is increased, the rate becomes more and more influenced by the position of these notes (i.e. higher notes = higher rate frequency).

Envelopes 

Wikipedia Commons

Envelopes are modulation sources that divide a sound or a selected parameter into sections:

A.D.S.R.

Attack - time to ascend from 0 to peak level

Decay - time of descent from peak level to sustain level 

Sustain - time of sustained level

Release - time of descent from sustained level back down to 0

By adjusting the time lengths of each of these stages, you can either subtly or drastically change the behavior and character of the effected sound source or parameter.  Thor offers four individual envelope generators: 

Amp Envelope

The Amp envelope effects the amplitude of your sound oscillators.  Each slider can be used to  determined the time duration of each stage - except the Sustain slider.  The sustain slider determines the level at which the amplitude is sustained.  It does not affect time because the sustain duration ends when a note is released.

Filter Envelope

The filter envelope functions in the same manner as the amplitude envelope, except this envelope modulates the behavior of Thor's filter frequencies.  As you may recall from my previous post on Thor's filter section, the individual filters have rotaries that can control the amount of influence the filter envelope has on their frequencies or parameters.

Modulation Envelope

The modulation envelope is slightly different in comparison to the amplitude and filter envelopes which both have a predetermined target.  It does not automatically modulate any parameter without prior assignment in the modulation bus matrix.  The mod envelope offers a tempo synchronization function that changes the fader parameter from milliseconds to steps ranging from 1/32 note -  to four full bars in length.  As you may notice from the image above, the modulation envelope does not have a sustain function.  Rather, its sustain is level is preset.  There are two additional features that are introduced with the modulation and global envelopes: Delay and Loop.  The Delay function does exactly what it says; it allows you to delay the onset of the modulation by a set time or beat length.  The loop function loops the delay, attack and decay stages repeatedly until a note is released (if "Gate Trig" is engaged).

The global envelope is similar to the modulation envelop.  It does not have a predetermined modulation target, so it only modulates parameters set in the modulation bus matrix.  The Global envelop offers both the delay stage, tempo synchronization and loop functions that the modulation envelope has.  However, the global envelope includes a sustain level fader and also incorporates a "hold" stage that determines the length of time the peak level is sustained before the decay stage begins.

I hope you guys enjoyed these articles on Thor.  Next I will be talking about the Grid of Death modulation bus matrix, the step sequencer, as well as the delay and chorus components.  Thanks for reading!

Thor Polysonic Synthesizer Part 2: Filters

The next set of components I would like to talk about are Thor’s filters.  Each filter has a unique function that can be used to cut harmonic content and shape a sound (called subtractive synthesis).

So lets take a look at the filters:

Low Pass Ladder Filter

This filter is just a “simple” low pass filter.  I say “simple” because it only has a single function: filtering out high-frequency content.  On the filter you have the capability to set the filter frequency and resonance level.  There are also controls that alter how the filter is effected by the filter envelope, velocity, and keyboard position.  You can also invert these functions as well as increase the amplitude with a linear slider labeled “drive”.  In addition, there is a selector switch that alters the slope (2x 24dB/18dB/12dB/6dB per octave).

The final selection switch turns on the ability for this filter to self-oscillate.  A self-oscillating filter can create a sine wave when the resonant frequency is high enough to oscillate itself. 

State Variable Filter

The state variable filter is more of jack-of-all-trades filter.  In addition to the common modulator functions, frequency/resonance selectors and “drive”, the State Variable filter allows you to change its function between Low Pass filter, High Pass filter, Band Pass filter, Notch filter or Peak filter.  You can also alter how close to high-pass/low-pass the peak and notch filters act.

Comb Filter

The comb filter is an interesting component that is normally used to add a chorus/flange-like effect to a sound.  This effect is achieved by taking a clone of the incoming signal, and delaying it slightly before summing the two signals back together.  This causes phase summation and cancellation at different intervals (when used with a pure sine wave).  When using more complex wave forms, more interesting “resonant regeneration” occurs.  There is a +/- selector that allows you to invert the resonant peaks caused by the phase modulation creating a slightly different sound.

Formant Filter

The formant filter is similar to the “wha” guitar effect pedal in that it can emulate the consonant “w” along with different vowel sounds (based on the spectral content of  the input signal).  The formant filter in thor allows you to replicate different consonants and vowel sound (albeit on a limited scale – nowhere near the ca[abilities of the human voice) in addition to changing the “gender” of the signal (most likely by altering the amplitudes of the lower frequencies).  The filter itself is controlled by a virtual X/Y pad, which can be manipulated (and even modulated via Thor or automation) to sweep through multiple consonants and vowels.  So how is this achieved?  Formant filters act like multiple band-pass filters acting on the same signal at the same time. 

This is just a brief look at Thor’s filters.  For more in-depth information, visit Propelloheads’ series called Thor Demystified, or this article from Reason Experts.

Next week I will take a closer look at modulation sources and the modulation bus matrix.  Thanks for reading and I hope you get a chance to play around with Thor!