Vix spectorgram issues

issues: fixes #1442 

Large amplitudes caused the spectrogram to "hiccup". This was due to the fact that the "radial graphic equalizer" generated a number of wedges proportional to the integrated power spectrum. For large amplitude audio events this could reach to the tens of thousands. Now clamping the the number of wedges to a reasonable value for visual presentation to avoid wasted computation.  
This was the number that could get extremely large, causing pointless computation and off-canvas rendering. This clamp value could probably be passed in in the JSON config.