Stereo Tool

And a few more updates.

1. "Pre Clip bass to protect against highs IMD" was affecting all frequencies up to 1-2 kHz. That didn't protect against any issues, but did reduce mids unnecessarily and potentially caused mids IMD.

2. "Pre Limit bass" just below that doesn't appear to help above 100%, but it does reduce bass and mids. So leave it at or below 100%.

3. Interesting observation: It appears that using "Highs vs rest threshold" at 100% with a higher value for "Highs clipping threshold" actually sounds better, up to a point. (Too high causes all the highs to be reduced, surprisingly; around +2-+2.5 dB seems to be a good range).

4. At such high highs clipping values, "curve" didn't do enough to protect against the highest highs pushing lower highs down. I've added an extra checkbox for that.

These 3 changes combined make the audio about 0.14 dB louder, with the same clipper input. That may not seem like much, but any improvement means that we're throwing away less audio, so (if we don't introduce extra IMD - I don't *think* that we do with these changes) a cleaner, more dynamic, more open and more stable sound.

(Measurement, Adaptive Bass Monster with 3 dB stronger clipping at 75 us pre-emphasis, original vs new settings: +0.15 dB up to about 3000 Hz, -0.2 dB between 4500 and 6000 Hz, same as before between 9 and 10 kHz, +0.3 dB louder from 11 to 14 kHz)