Lissajous Go Figure

Lissajous Go Figure

A DIY vectorscope is constructed from two pairs of speakers and a laser light pen. The four speakers face inward into a wooden box. Opposite pairs of speakers are wired out of phase, in a push-pull configuration, one pair for the horizontal axis and the other pair for the vertical axis, with each pair connected to one channel of a stereo audio signal. A laser light pen is suspended taut with fine thread and hot glue in the center of the four inward facing speakers. As stereo audio is fed to the device the pen position is displaced by movement of the speaker cones to which it is tethered. Laser light from the pen projects an illustration of the x,y plot of the interference pattern of the two waveforms of the stereo signal. In other words, the device can be used to display Lissajous figures.

The instrument used to provide the stereo audio signal is a custom built synthesizer. The unit has 6 oscillators with separate control of the sin, triangle and square-wave components. Each oscillator can be panned or used to modulate another oscillator. This installation is intended to be hands on, allowing visitors to make their own adjustments to the oscillators. Users are welcome to experiment and discover what patterns they may create with the controls. A tuner will also be provided to allow precise tuning and/or reading of the oscillators.

Previous Documentation:
http://www.soundart.org/dterep-1.html

Category:

Howto & Style

Tags:

• Lissajous
• oscilloscope
• vectorscope
• laser
• synthesizer

[DocLow]

Jaja. Really nice. Really interesting, even if the result is less than perfect. Congrats.

[gjwildes]

@DocLow Low frequencies work best since the speaker cones move less and less at higher frequencies. I shot this video with the amp maxed out to achieve the greatest image size over a short projection distance, resulting in some distortion in the speakers and camera mic. As an alternative, one could use a lens to magnify (I often use one side of a pair of binoculars turned backward) or project over a greater distance (not a problem for a laser).

[janmorez]

Woah! Ingenious!

[g33kstuff]

cool stuff. Yould you also send me a schematic? would be really helpful for a school project of mine...!

Thanks.

[uploadJ]

Really cool dude; ingenious. Speakers used as servomotor drivers positioning a Laser, 5/5

[jackofnowhere]

could you send me a schematic on how to make this? ...this looked really cool and i need to do a project for my physics class

[jeabo0adhd]

that is so nerdy, congrats!

[tonttu303]

Interesting that x-y device :)