Limit ladder filter to safer maximum values

https://forum.pjrc.com/threads/60488?p=269918&viewfull=1#post269918

filter_ladder.cpp

@@ -37,8 +37,8 @@
 #include <stdint.h>
 #define MOOG_PI ((float)3.14159265358979323846264338327950288)
 
-#define MAX_RESONANCE ((float)1.1)
-#define MAX_FREQUENCY ((float)(AUDIO_SAMPLE_RATE_EXACT * 0.49f))
+#define MAX_RESONANCE ((float)1.07)
+#define MAX_FREQUENCY ((float)(AUDIO_SAMPLE_RATE_EXACT * 0.249f))
 
 float AudioFilterLadder::LPF(float s, int i)
 {

gui/index.html

@@ -4567,11 +4567,11 @@ double s_freq = .0625;</p>
 	</p>
 	<p class=func><span class=keyword>resonance</span>(level);</p>
 	<p class=desc>Set the filter's feedback level for resonance.  The
-		usable range is 0 to 1.1, where values over 1.0 can cause
+		usable range is 0 to 1.07, where values over 1.0 can cause
 		the filter to self oscillate.  When an audio signal is present
 		at the resonance control input, it overrides this setting.
 		Only positive signal values are used.  A full scale 1.0 signal
-		creates resonance setting 1.1 (self oscillation).
+		creates resonance setting 1.07 (self oscillation).
 		Any negative signal input is treated as zero.
 	</p>
 <h3>Examples</h3>