Patterns have been seen from about 500Hz to 5000Hz. The best range to show in a class is between 2000 and 3000Hz. There are many patterns very close in frequency in this range with amazing complexity. I recommend this instructable especially for educators as it makes a great intuitive and hands-on introduction to acoustic with exciting experiments but without spending too much.

Take your piece of acrylic, mark where the 4 rods touch and drill holes large enough to allow the rods to go through. Also drill a hole in the exact center large enough to allow the center rod to go through. This hole should be just barely large enough to allow the center rod to move freely without binding, but also tight enough to keep it level. Each of the component of this experimental kit are also sold separately as individual products, so you can easily replace any lost or damaged parts. A function generator is a handy power amplifier tool designed for use in various experiments covering simple harmonic oscillation, AC electricity, and induction. This unit outputs sine-wave, triangular wave, and square wave voltages with adjustable amplitude and frequency. When used with this experimental kit, it's purpose is to power the vibration generator (which will generate mechanical waves from the output of the function generator). If you want to find the secrets of the universe, think in terms of energy, frequency, and vibration.” — Nikola Tesla Good demo to show how complicated modes of vibration can get when we increase the number of dimensions. ReferencesVibration generator includes a holder for a stand rod on the rear side fordemonstrations of standing waves in a coil spring These are spare parts that can be used with this kit in case of loss or damage to individual components. These patterns, especially at higher frequencies, show amazing complexity and symmetry. If one can stand the noise, it is easy to spend hours finding new patterns in the sand. SoundScribe Plus supports wireless and wired connectivity allowing you to connect a microphone or other pre-amplified audio source directly using the integrated 3.5mm auxiliary input. Use a microphone to generate unique Cymatic patterns interactively using your voice or endless other sound sources. There were a few places online that we found instructions on how to build a Chladni plates. In particular there is this Make article Chladni Plate: Visualize beautiful acoustics and another instructable here Mechanical Wave Driver for Chladni Plate.

All objects, including Chladni plates, have a set of natural frequencies at which they vibrate. A system, such as standing waves in a musical instrument, tends to vibrate at certain discrete frequencies called natural frequencies or eigenfrequencies. Once vibrating at a certain frequency, a structure deforms into a corresponding shape: the eigenmode. Imagine you’re at a classical music concert. The orchestra has finished warming up. The lights dim. A single spotlight appears on the violin soloist as she moves front and center stage. She raises her bow and a hush falls over the audience as you anticipate her first, resounding note. The violinist draws the bow across the string…and the note that results carries beautifully, reverberating throughout the auditorium for your listening pleasure. The Complete Chladni Plate Experiment Kit with Function and Vibration Generatorsprovides a comprehensive approach to educating students about waves and sound. The kit includes two metal Chladni plates, with a vibration generator to excite oscillations and sound waves. The included function generator allows the demonstrator and students to experiment with varying degrees of amplification for greater experiment diversity. What's Included? Before beginning with this experimental set, you must ensure you also have a function generator and experiment leads (both sold separately).Once you have the required equipment, and are ready to start your experiment, follow the below instructions: The transducer has been salvaged from a large hard-disk drive. It consists of a heavy electromagnet and current coil -- not unlike the magnet/voice-coil arrangement in a loudspeaker.Chladni Plates: The first step to Visualize Acoustics! At special frequencies, standing waves appear on the plate, driving the sand away from the points of large vibration to points of no vibrations. Unique patterns are formed at different resonance frequencies becoming increasingly complex and beautiful as the rate of oscillation increases. A Chladni plate consists of a flat sheet of metal, usually circular or square, mounted on a central stalk to a sturdy base. When the plate is oscillating in a particular mode of vibration, the nodes and antinodes that are set up form complex but symmetrical patterns over its surface. The positions of these nodes and antinodes can be seen by sprinkling sand upon the plates; the sand will vibrate away from the antinodes and gather at the nodes. A ny amplifier will do - you just need something that'll boost the audio signal from your computer to power the large speaker. I used a guitar amplifier. It has a feature to take an aux-in and it worked perfectly. You may also need a 3.5mm audio cable to connect the two together.

E. F. F. Chladni, Acoustics: Historical and Philosophical Development, ed. R. B. Lindsay p.156 (Dowden, Hutchinson & Ross, 1972) Can we “see” sound? Not directly, but we can come close. By changing our perspective, we can learn a lot about the nature of acoustics. One way to observe acoustics phenomena is by studying standing waves in a solid medium known as a Chladni plate. A special technique creates patterns on the plate that reveal sound’s physical nature. Explore the amazing world of Cymatics with this low profile, easy to use Chladni Plate. Connect to the SoundScribe wirelessly using any Bluetooth capable phone, tablet, or laptop.A representation of Chladni patterns on a guitar plate. Compare the left image at a lower frequency (109 Hz) with the right image at a higher frequency (426 Hz). “Seeing” Sound with Structural Mechanics Simulation Among his achievements, he was able to determine sound velocities in gases using an organ pipe and developed Chladni’s law. This formula relates the frequency of modes of vibration for a flat circular plate. Among other applications, Chladni’s law can help predict patterns of vibration on flat surfaces and describe the vibration of cymbals and bells. These sound waves move and create shapes with the substance on the Chladni plate, offering a visual demonstration of how sound travels. This makes it highly suitable for use in science and music classes. What Are Chladni Plates?