Stereo Tool

I just found 2 more bugs in the pre-ringing filter code. If pre-emphasis is enabled some of the highs might be removed. If in Multiband the equalizer is used, and band levels are increased, the same thing can happen for the bands that are increased too much. Will fix those tomorrow. (Added to todo list).

Changed:
- I have removed the phase rotator from the Stereo filter (so that's working again as before, don't forget to turn Stereo Image off or set Angle to 0 degrees!).
- I've made a separate Phase Rotator filter that's now placed directly before the Singleband compressor (*)
- If the Phase Rotator is turned on (in this version that's always the case, I haven't yet added it to the user interface), I'm using a weaker setting for the pre-ringing filter (but the pre-ringing doesn't seem to get worse).

Todo for Phase Rotator (will do this tomorrow):
- Add to user interface
- Fix Pre Ringing filter volume calculation

Building now.


(*) Phase rotation has NO effect on AGC (RMS based) or Multiband (bands are so small that there are no asymmetry issues). However, it may cause very slight artifacts (especially at lower latencies) and, more importantly, if a sound is placed before another sound due to the phase shifts, it might get played back way too loud if AGC and Multiband are placed after it. (I _have_ to place the Singleband compressor after it because it does behave differently if after phase rotation).

Uploaded as BETA3A.

Will test the newer version later on Hans. Great Job!
Been listening for 5 hours in a row with my studio headphones on so my ears are still numb.
All harmonic distortion, especially in intro's , that I have known simular processors to freak out is completely gone.

That bug with the pre-emphasis I think I have noticed that but it is difficult to compare when you use mpx out.
For some reason the 'bypass' button mutes it all. It would be nice to have a bypass button that just bypasses the processing and go clean to the pre-emphasis, stereocoder etc.

Hm, a very short asymmetry won't affect Stereo Tool's processing much - and if it lasts longer the attack is not that fast so the effect would be very small. Anyway, the filter is now placed behind the multiband compressor, so if it were a problem it should be fixed now
The "bug with pre-emphasis" - what bug is that?

Note: In case you heard weird sounds when a loud sound kicks in (which your first remark seems to indicate): Please try the new version - the previous one had a weird "kick-start" sound where sounds started at a higher frequency and then very quickly dropped to the actual frequency. I no longer hear that in the new version (due to a number of changes).

Last version still sounds good ...
I can't belive how this changed whole picture of processing... Maybe because of my excitement i can't hear that pre-ring .. any particular song ?

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i agree for bypass button in Standalone version...
If pressed, it'll be nice to hear just pilot, rds... (and unprocessed audio)

edit:
dam', i am hearing some voices "robotized"

Hehehehe, either me too long with a headphones on or you having a short night.

...If pre-emphasis is enabled some of the highs might be removed. .... (Posted: Sat Apr 03, 2010 3:45 am)

Hm, it's possible that certain aspects of the sound are 'changed' by this.

What I will do: I'll make a lot of settings configurable. Among others, iZotope starts processing at 1000 Hz and I start at 500 - which means that the amount of movement between sounds is a lot higher. But first (now) I'll build a version where I turn the pre-ringing removal for this particular filter off - that might do more harm than good.

So: Version without pre-ringing removal coming up in a moment.


Note: About the pre-ringing: It's nearly gone, and I was also using the pre-ringing removal filter.

Lol! I thought you were referring to your previous post or something . With pre-emphasis enabled and Loudness on, the highs will get reduced anyway (more at higher Loudness values). So that might also be what you're hearing.

To Bojcha about robotic voices: I've just tried what happens if I increase the start frequency of my filter to 1000 Hz (from 500) and reduce the processing strength. Same effect! So I'm building a version with those 2 changes, and without Pre Ringing filter, now.

Expected result: The audio should AT LEAST be a lot closer to the original (less movement in time per frequency range). And nothing should be removed by the pre-ringing filter.

This Robotized Voice caused bu Phase Rotatator .. other processors have this side-effect.. some more, some less...
Curently in ST this is not so dangerous and certainly less then other processors with phase rotator.

I know many peoples who actually loves this effect.

btw, i think in US Phase Rotating is Forbiden.
Maybe that's why some processors have always on Phase rotating and another button/phase rotator On/Off.