Audio Examples 2

Recordings made during the measurement phase of my project at IRCAM

In the spring of 2013 I spent 5 months conducting a Musical Research Residency at IRCAM, working to create a physical model of the interaction between a resonating body and an electromagnet. The result of this residency was the Induction Connection, currently built into Modalys. During the initial phase of that project, I recorded the following files in order to test the responsiveness of piano strings to electromagnetic excitation in a controlled setting.

A few additional notes:

  1. Some of the input audio files (i.e. the files played through the electromagnets) contain aliasing at higher frequencies. I left these in as the results are rather interesting sonically.
  2. Most of these audio files have long decay tails, since undamped piano strings ring for some time after the excitation has ceased. In most cases I simply faded this out.
  3. All of the files have been normalized, though the application of noise reduction was avoided. The noise level thus indicates the resulting relative volume of the piano strings to that type of input. In other words – files with more background noise indicate that the given input doesn’t generate a great deal of string displacement.

Multiple Strings

This first group of files was created by playing a single sound through all 12 electromagnets, set above the following strings (C4=middle C): A1, Eb2, E2, Bb2, B2, C3, D3, F3, G3, Bb3, C#4, G#4. All dampers were off.

Example 1: 1 second sine sweep

Example 2: 10 second sine sweep

Example 3: 10 second square sweep

Example 4: 60 second sawtooth sweep

Example 5: 60 seconds of white noise

Single String

The rest of the examples involve the excitation of a single string, as follows (C4=middle C):
– examples 6-11 – C#4 (trichord pitch)
– examples 12-16 – Eb2 (bichord pitch)
– examples 17-20 – F1 (monochord pitch)
– examples 21-23 – C#4
– examples 24-26 – Eb2
– examples 27-29 – F1

Electromagnet over C#4, dampers off

Example 6: 1 second sine sweep

Example 7: 10 seconds of white noise

Example 8: 10 second sine sweep
Note the simultaneous presence of two distinct sonic profiles emanating from a single string: the ringing fundamental remains prominent as the frequency sweeps upward.

Example 9: 60 second sine sweep
These 60 second sweeps are some of the most sonically interesting examples.

Example 10: 60 second sawtooth sweep
Quite similar to the sine tone, with slightly more buzz near the fundamental (no surprise there).

Example 11: 20 ms impulses (white noise)
Remember – nothing is touching these strings.

Electromagnet over Eb2, dampers off

Example 12: 1 second sine sweep

Example 13: 10 second sine sweep

Example 14: 60 second sine sweep

Example 15: 10 seconds of white noise

Example 16: 20 ms impulses (white noise)

Electromagnet over F1, dampers on
This lower range of strings is much quieter in general, due primarily to the following factors:
1) The strings are of greater mass, and thus require more energy to excite,
2) The displacement of the strings is significantly greater, thus requiring that the electromagnets be positioned more distantly from the strings.

Example 17: 1 second sine sweep

Example 18: 10 second sine sweep

Example 19: 60 second sine sweep

Example 20: 60 seconds of white noise

Electromagnet over C#4

Example 21: sustain on fundamental, then gliss from fundamental to 2nd partial over 20 seconds

Example 22: sustain on fundamental, gliss from fundamental to 5th partial over 30 seconds, then gliss back down

Example 23: LFO applied to fundamental input frequency (LFO freq=.13, amp=1.99)
Note the flexibility – the pitch actually bends! The beating is caused by the ringing fundamental sounding simultaneously with the bent pitch.

Electromagnet over Eb2

Example 24: sustain on fundamental, gliss from fundamental to 2nd partial over 20 seconds, then gliss back down

Example 25: sustain on fundamental, then gliss from fundamental to 5th partial over 30 seconds, then gliss back down

Example 26: LFO applied to fundamental input frequency (LFO freq=.13, amp=1.99)
With these lower strings the bend in pitch becomes more prominent

Electromagnet over F1

Example 27: sustain on fundamental, then gliss from fundamental to 2nd partial over 20 seconds, then gliss back down

Example 28: sustain on fundamental, then gliss from fundamental to 5th partial over 30 seconds, then gliss back down

Example 29: LFO applied to fundamental input frequency (LFO freq=.13, amp=1.99)