Goyder’s Line (Maurlia Sound Studio Vol. 2) Preview

The second edition of my Maurilia Sound Studio imprint will consist of three versions of my sawtooth-vocoder work, Goyder’s Line (2014-2015), which is a drone-based work realised using Max/MSP, Microkorg, Moog MF-108X and Electroharmonix Memoryman. The work is inspired by George Goyder’s line of South Australian rainfall, using the original line to determine the frequency of a sawtooth wave over a set duration, which is then routed as the carrier signal to the Microkorg’s vocoder. A second line (based upon future climate projections) determines the frequency of the vocoder’s modulation signal. This results in instances of phase cancellation and harmonic overtones, with a predominant drone throughout  (provided by the base notes of the vocoder).

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MicroKorg Vocoder, light control and feedback.

The Vocoder is being controlled by two sawtooth waves generated in Max/MSP. These sawtooth waves are routed to the Vocoder as the Carrier and Modulation signals. 

The frequency value for the the sawtooth waves is produced by a light sensor which reads the fluctuating (single) value of reflected light in my studio space. Once received by a Serial~ object in Max/MSP, the first sawtooth frequency value remains unchanged whilst the second frequency value (Modulation signal) is multiplied by 3.51 resulting in a scaled frequency value. 

E.G: if the Carrier’s frequency value is 104Hz, the Modulation frequency value will be (104 * 3.51 = 365Hz)

On the MicroKorg, a perfect fifth is held (E1-B1) and the incoming Carrier and Modulation signals undergo processing via an Electroharmonix Memoryman set to a reverberant delay setting with feedback which his gradually increased.

Weekly Beats 2014 #18: 5/2 “Goyder’s Line And A Shadow Passes”

freetronics light sensor

For the past couple of weeks, I’ve been experimenting with a light sensor and an Arduino Eleven board to control parameters in Max/MSP – at this stage just simple stuff like controlling the frequency amount of a waveform.

At the same time, I’ve been exploring the vocoder of my Microkorg, using basic Carrier and Modulation inputs to affect the vocoder’s oscillator. Last week’s submission (Goyder’s Line And A Shadow Passing) utilised two rising sine waves as the Carrier and Modulation inputs. Whilst the result was as I anticipated – very subtle and imperceptible – it was later pointed out to me that there would probably not be any actual affect on the vocoder’s oscillator since the Modulator imposes its harmonic characteristics on the Carrier, and since we’re talking about two sine waves, well…this should have occurred to me. I do have a tendency to get distracted by technology and overlook the basics from time to time, and I think I’ll be re-learning the rudiments of all the things to my grave.

So, this time around I used two sawtooth waves as the Carrier and Modulator (harmonic range = good!) and raised the Modulation frequency above that of the Carrier frequency using a simple Max multiplication object. * I’ll go into further detail with the Max/MSP patch in a later post.

A perfect fifth is held on the Microkorg (E2; B2) and as the light level changes, the relationship between the Carrier and Modulation frequencies shifts resulting in a change to the overall structure of the sound heard through the vocoder. Since I recorded this track in the late afternoon (the full version is 20 minutes long), the light level gradually falls as reflected light being read by the light sensor diminishes.