(4, 6) −
High order, tight grid. The grains take noticeably longer to settle.
- Plate
- Square, free edges
- Mode numbers
- m = 4, n = 6, minus combination
- Shape
- cos(4πx/a)cos(6πy/a) − cos(6πx/a)cos(4πy/a)
- Wavenumber k·a
- 22.65 (a = 240 mm)
- Frequency
- 2,192 Hz on the reference plate