Stereo Tool

Note: Only very small changes in this version.

I've made a small change to the code that protects against voice vibrations. At first glance the result appears to be slightly better now but I'm not really sure, so feedback from others (some people seem to hear this much better than others including me) would be helpful. Normally if things are difficult to hear I can measure them but for this specific issue I don't know how to.

In BETA010 I had forgotten to adjust highs gap protection in the composite clipper - that's fixed now. It doesn't really seem to have much effect though.

I have optimized the highs gap protection for the non-FM version of the clipper because the highs aren't that problematic without pre-emphasis anyway. This means that for non-FM the behavior is now a bit closer to that of before BETA010. I don't expect a noticeable degradation. (I should probably measure it though).


Windows 32 bit:
Windows stand alone: http://www.stereotool.com/download/ster ... 52-011.exe
Winamp DSP: http://www.stereotool.com/download/dsp_ ... 52-011.exe

CHANGES:
- Highs Gap Protection: Turn 3rd step off for non-FM mode.
- Highs Gap Protection: Forgot to make changes in Composite Clipper mode.
- ABDP: Check mid tone intermodulation distortion protection code. viewtopic.php?f=3&t=5734&p=26879#p26879 MADE A VERY SMALL CHANGE, WAITING FOR FEEDBACK. MIGHT BE BETTER OR MIGHT BE WORSE.

TODO:
- ABDP: Calvin Harris ft. John Newman - Blame has distortion in lower highs; Highs distortion protection doesn't seem to handle it properly. Except for that I'm now getting a good sound for almost all tracks with bass clipping set to 100% (!) and Highs Priority to 20%, Sloppy at maximum. Cause: Highs in this track are at around 4 kHz and I'm not filtering highs for harmonics there. Very unusual track, ignore for now.
- ABDP: Mid tone intermodulation distortion: Make new filter at start of ABDP to control mids clipping level. Clip lows and mids separately, then together, measure volume loss for each and then use that as new clipping levels. Only in case where there are loud tones present (voices) with loud bass. Bojcha: Phase Tornado fixes it. Problem seems te be caused by combination of: 1. Loud bass below 100 Hz (maybe even lower); 2. Loud mids consisting of a constant tone with no or very little other sounds. But apparently only if this constant tone has a lot of harmonics - a sine wave comes out nearly ok. Ok. Fix almost there now. Todo: Improve detection (bigger frequency range? Add highs!!!). Todo: Measure at 75% clipping as well. TODO: Harmonics turnoff should not affect bass!
- Sloppy causes crackling sound in piano's. Should probably be switched off is there are very little highs.
- Hide panels in password protected mode or something
- Check pilot generation code (57 kHz harmonic) -> Pilot is ok (generated output does NOT contain this tone), this is only a GUI (frequency analysis for displaying) issue. Ignore.
- GUI: Weird jumps at 100 ms buffer size reported by DJ_DOGGY
- Check Multiband settings Bojcha in Skype

PREVIOUS:
- Fix declipper + PNR. Does it cause problems if it's used as intended? MUST BE TESTED TO MAKE SURE IT DOESN'T DAMAGE THE SOUND
- Fix crash when clicking on volume bars.
- Highs Gap Protection: 2nd step does almost nothing - why? - Correct, but seems ok this way...
- Highs Gap Protection: power_X must not be used (sounds better without), but it must be used for something else because if power_X is 0, the current filter is insufficient. --> Now not using power_X anymore, but 3 steps instead of 2 in HQ gap mode. This seems to be very close to the optimal result. Need feedback on this.... it appears to be ok but I'm not 100% sure that the problem is completely gone. And I still need to test if it doesn't increase highs intermodulation distortion (probably not though).
- Don't use Sloppy value when ABDP is disabled.
- Highs Gap Protection caused a jump in the spectrum between 3.5-3.8 kHz for loud highs. This is now smoothed over a bigger area (2400-4800 Hz).
- Bad gap in ABDP - causes highs to sound less full. Fix ASAP! Only in Composite mode! Was introduced in one of the previous beta's
- Make Configuration, Repair and Processing settings saveable separately.
- Split filters in Restoration / Processing.
- At Band Coupling '0' the values in the GUI weren't recalculated properly.
- Default value for Sloppy was 0% (-99 dB), should be 100%.
- ABDP: Added new "Sloppy" slider. Effect: Slightly louder, 0.5 dB more highs! And probably less pumping due to highs. (*)
- Band coupling settings don't work if Band Coupling slider in main Multiband window is set to 0%.
- Declipper result is very bad if PNR is used before it. NOT SURE YET IF IT'S REALLY FIXED.
- PNR can also be done AFTER declipping.
- Display FM lowpass frequency at bottom when FM output is used.
- Show warning when PNR is disabled due to changed settings.
- Added Multiband compressor Band Coupling matrix. You can use this to overrule the standard band coupling settings. Only available in Extreme Tweaker mode, awaiting responses to see how useful it it (if it is useful I'll move it to Expert mode).
- Advanced Clipper: Advanced Bass Distortion Protection (ABDP): Drop in output when strongly clipping around 2600-4000 Hz is reduced.
- Advanced Clipper: ABDP: "Smooth Slide" slider added to make transition between deep bass (clipped) and less deep bass smoother. There used to be a drop upto the 2nd configured bass frequency, with this switch enabled the drop is smoothed (maximum at 1st configured bass freq, gone at 2nd). Result: Warmer, more open, less 'restrained' sound. But probably also a bit more intermodulation distortion. (which might be fixable by changing the frequencies a bit). (*)
- Added PNR Noise & Hum
- PNR analysis data is saved now

Note: CPU load for Highs Gap Protection in HQ mode might be slightly higher (haven't tested it yet; I'm doing more but I have also optimized the existing code).

My take is that highs sound a tad less "crispy" in this build. That isn't necessarily a bad thing, I just need to listen more. They sound smoother to me right now. That might improve source to source consistency a bit as a side advantage.

You can probably change this by increasing 'Highs priority' in the Advanced Bass Distortion Protection section.

Did you test this with the composite clipper? I've noticed that the effect on the highs is much smaller with the composite clipper enabled, and the effect on the mids/lows is smaller. Which means that this might be a reason to not make this change when the composite clipper is used. Or to make it switchable...

My apologies for the slow reply. I tested this in non-FM mode, so no composite clipper in the mix here. I played with the sloppy slider (which I've left at 0/100% since introduced), and it can definitely make things sparkle, but the effect has other disadvantages. It could be my imagination, too. Honestly, the last couple of builds have me scratching my head.

When I listen to too much processing, I can get fatigued and everything sounds bad. If no one else hears a difference, it's probably me. I took a break at some point today to reset my ears. I'll pick it up again in the morning.

This could very well be true. I have made changes which protect the lows and mids against drops from extreme highs. But that comes at a cost: Highs might be more gritty. I haven't really noticed that however, and measurements show much more effect on lows/mids than on highs, so I assumed that it was ok. I haven't tested non-FM though, where the problem that I've tried to solve is much less present in the first place.

On FM lately I've been noticing an - how do I describe this - 'restless' sound on mainly the bass when there's a lot of action in the highs. Which is what these changes are supposed to solve.

There are other changes that might also go both ways (good or bad). And Sloppy can definitely make some sounds (mainly voices with loud bass) worse - it adds distortion in the mids in that case which are clearly noticeable. When such sounds aren't present the sound improves though. At least at first glance...

So, I'm indeed not really sure if I'm moving in the right or the wrong direction. For FM I think the improved protection against loud highs is good. I'll do some more tests in the next few days, also with non-FM presets, to see what's happening and if I can compensate for any negative effects using Highs Priority.

These numbers are not matching...
but this release sounds super on my system.

Update: BTW this was the standalone version only, it is ok on the DSP (Windows stand alone: http://www.stereotool.com/download/ster ... 52-011.exe)

Disable the lowpass in the FM Transmitter panel

ah, yes that works. Thanks

I privately sent you my old preset to put back in the next build. What I was hearing (and not liking) was an option I selected. It's hard to say which one because I did several small adjustments at once (I know, I'm a bad boy). I suspect it was either of the two new options in the Advanced Clipper. I'll need to do more investigating. I'm back on my old preset with 7.52 and it sounds as good as ever.

Better solution is to set the FM lowpass filter in the FM settings and the global one in the bandpass settings...