Spiral State
Disordered State

This demonstration uses the same parameter values (and even has the forcing in the corner) as the previous one, but shows a self sustaining spiral source rpoducing the waves. Gerally the waves from the source with the higher frequency beat out the lower frequency waves (you can understand this from dynamics of the shock between the two sets of waves) - in this case the faster spiral waves overcome the lower frequency waves from the driving at the corner.