Plates are very interesting systems, in that they can display a rich dynamical behavior. When used as reverb units, the vibrations are small: the large modal density accounts for the typical whippy character of plate reverbs. When struck, plates often display nonlinear behavior, perceived as shimmering and crashing sounds. This is better understood within the context of wave turbulence, where the energy flux through scales is described statistically.
One of the most attractive features of linear plate dynamics is perhaps the possibility of simulating plate reverberation. Despite not being sound synthesis per se, this effect can be entirely modeled using physical principles. A major advantage of physical modeling over convolution or sample-based reverb is the ability to dynamically extract the output on the plate by moving the output locations. This results in a very enjoyable phase movement.
Below are comparisons of dry and wet sounds using different plate settings. The sounds were obtained using the Physical Audio PA1 plate reverb plugin, available here.
| Vocals (Dry) | |
| Vocals (Wet, Static) | |
| Vocals (Wet, Dynamic) |
For sufficiently small plates, a modal algorithm can run fast enough to allow real-time simulations even on consumer hardware. The plates can be designed at will and played at multiple locations with different amplitudes, resulting in very organic sound textures.
| Rhythm Example | |
| Gong 1 | |
| Gong 2 | |
| Gong 3 | |
| Gong 4 |
Larger plates at high amplitudes give extremely rich simulations, from gong-like to cymbal sounds. In this example, different plates are driven with control signals (pure tones), and the output displays an extremely rich spectral content. This is a trace of wave turbulence!
| Driven Plates |
One of the advantages of physical modeling is the possibility of designing instruments with unrealistic dimensions. Here's an example of an extremely large plate, with no loss. You can hear the turbulent cascade developing from low to high frequencies.
| Earthquake Gong |