Hello,

I'm trying to restore a fairly recent collection of MP3's with sample rate cut off ranging from ~20.5 to ~16.5. To determine the best tools for the job, I experimented with Vitalize and Unchirp on a lossy track I transcoded from a lossless source to be able to compare the results with original lossless (for testing purpose before I could do the real work)

While Vitalize does the job, Unchirp is absolutely phenomenal but the issue is it's shaping the sound, boosting some frequencies and suppressing others, that while the sound has detail but mostly differs from the original source. It's like an EQ is applied post process to the stream in a bad way (sound is not natural)

Now I understand I can't restore the full information stored in the lossless source and te new transients that Unchirp adds is based on the best guess but the character of the sound should at least be identical (like in transcoded lossy). Vitalize doesn't have this problem, it just adds the new transients, does nothing to the sound itself. Comparing the spectrograms, the results of Unchirp is phenomenal. It just needs to be tweaked correctly.

For the past 5 days, I'm trying different configurations to achieve this but unable to do so. Is there a kind soul reading this can help me out with some custom presets that I could use. Now I know that every source material is different and needs different configuration, one shoe fits all doesn't work in audio mastering, but anything close that would preserve the natural sound while boosting it will be highly appreciated.

I Will be eternally grateful to you

 

Please send spectrogram screenshots before/after for better understanding

 

Of the three Zynaptiq products I used - to me Unchirp gave the least success.
Reading your post, I'm thinking, maybe you could use a match EQ plugin after Unchirp?
Take the 'unchirped' signal as a reference, and match this with the 'post-Chirp' sound. Maybe that works..
You can do this with Fabfilter Pro-Q, so over to Dan Worrall:

 

Try Unfilter before/after Unchirp.

 

Thank you for the response boomoperator, That's a neat trick I tried but it doesn't seem to be working. Myabe it's not the EQ and the compressor ?

 

Hi triggerflipper, tried that too and it mildly improves the harmonic character but takes the warmth (depth) away from the track so I decided not to use it. Plus I want to keep the processing to minimal. The EQ trick is a neat solution suggested by @boomoperator but unfortunately it ain't working.

Edit: Can unfilter be used to copy/paste the profile from one track to another like EQ match ? Is that possible. Maybe I can copy the sonic profile of the lossy track before processing and apply it to the post Unchirped phase. Don't know how to do that or even if it's possible.

 

@ mods :

Does the forum rules allow uploading/linking to audio files ?

 

Been playing with this plguin too, after seeing this video

But since I got no access to a monitoring setup right now, I left it till better days when I'll be able to actually hear manipulations that I'm doing...

 

I'm trying to restore a fairly recent collection of MP3's with sample rate cut off ranging from ~20.5 to ~16.5. To determine the best tools for the job, I experimented with Vitalize and Unchirp on a lossy track I transcoded from a lossless source to be able to compare the results with original lossless (for testing purpose before I could do the real work)

-- What do you want to achieve? Retrieve the lost part of the spectrum? Dequantize? Retrieve transients? Or all of that?

While Vitalize does the job, Unchirp is absolutely phenomenal but the issue is it's shaping the sound, boosting some frequencies and suppressing others, that while the sound has detail but mostly differs from the original source. It's like an EQ is applied post process to the stream in a bad way (sound is not natural)

-- Vitalize retrieves the lost parts of the spectrum, but not so efficiently.
-- Unchirp is nominally a do-it-all tool, but it's got high THD, has a built-in EQ that users can not control (avoid). The treble boost enables you just to boost treble even more. And if you want to 'unchirp' the sound, you should actually reduce the transients, because they make chirping more stand out.

Original/ Processed with Unchirp:



Now I understand I can't restore the full information stored in the lossless source and the new transients that Unchirp adds is based on the best guess but the character of the sound should at least be identical (like in transcoded lossy). Vitalize doesn't have this problem, it just adds the new transients, does nothing to the sound itself. Comparing the spectrograms, the results of Unchirp is phenomenal. It just needs to be tweaked correctly.

-- 'New' transients can not be created, only the existing ones can be boosted. You probably mean 'harmonics'?
-- Take a look at what Thimeo Stereo Tool can do about the lost spectrum. Unchirp is very far from that.




For the past 5 days, I'm trying different configurations to achieve this but unable to do so. Is there a kind soul reading this can help me out with some custom presets that I could use. Now I know that every source material is different and needs different configuration, one shoe fits all doesn't work in audio mastering, but anything close that would preserve the natural sound while boosting it will be highly appreciated.

-- Don't use Unchirp at all. Use Thimeo Stereo Tool for missing spectrum ('Absolute Highs' module), and 'Dequantizer' (with strongest settings) module to remove chirping. Use some good quality transient shaper like Voxengo Transgainer for transient boost. Don’t' use EQ-ing if it is not necessary.

UNCHIRP is technically a pretty bad program:
upper - at default settings, lower - all knobs at zero

 

Last edited by a moderator: Sep 2, 2023

I think so. @Olymoon , @No Avenger ?

 

You can link to audio files, if they are not copyrighted.

 

I was about to mention Thimeo Stereo Tool since I whole-heartedly recommend it over Zynaptiq. For a transient shaper I would personally recommend oeksound Spiff or Newfangled Punctuate over the competition. I generally dislike transient shapers in general but Spiff & Punctuate sound good to me. Zynaptiq also has a really damn good transient enhancer in Unchirp but I no longer use it for the reasons you listed above.

 

i found Unchirp to be useless overall
a far cry from what was advertised

 

Yep stereo tool is the shit. Been using it for returning dynamic range to mangled hi-res 16b/44k - 24b/96k (not archival compressed) source recordings that have unfortunately been hit with so-called "modern" mastering. Mainly for what I call DE-Mastering. You know what I mean - those square/rectangular completely solid waveforms that sound like absolute crap due to the fact all the dynamic range has been sucked out of them (i.e. basically more or less every track 'mastered' by mainstream mastering houses after the turn of the millennium). You have to be careful though when using these tools. If they are overused or used incorrectly they have the potential to create more problems than they fix.

I won't bother attempting to "fix" stuff that has been lossy-compressed. I will simply re-get the original track in a hi-res format 16/44 - 24/96+ and use FLAC to archive it. The only trouble with this scenario is when re-getting audio that been "re-mastered" after 1998~2002. More than likely the result of that "re-master" left the audio in a condition that will need to be DE-mastered before archiving it. In some cases I have come across "re-mastered" audio that was so badly mangled I had to seek out and find the original vinyl album and do a hi-res restoration of that original audio.

 

Last edited: Sep 2, 2023

i absolutely agree

'remastered' is often a negative these day...

i think they just do them in bulk without listening to the result alot of the time
similar stuff has happened with films 'remastered' to Blu-ray and such
no effort applied whatsoever sometimes

 

iPhone speaker targeted mastering

 

All knobs shouldn't be at zero. Transients and warmth should be at max. This is what I get :



I don't know about the lpf though. It remains even when the plugin is at 0% wet. Some sort of anti-aliasing ?

 

Thank you for taking time and making expert comments pratyahara. Yea, I'm trying to do all of those. I understand I can't restore lossy files to their bitperfect sources but I want to get as close as possible both sonically and visually.

Here are some results from both perfect declipper and Unchirp.

Original lossy source:


With Unchirp:


With Perfect declipper:


Perfect declipper works fine but I don't hear any changes in terms of audio quality. Maybe it it stays on the safe side and does too little? On the other hand Unchirp does a bit too much. File the spectrograms look very close to the original source, it adds too much color to the audio.

The problem with unchirp is that it has too much parameters to control but I believe with right tweaking it can be done. The problem remains as you noted, the build in EQ hence my request for a preset by the very intelligent people here.

I'm in now way downplaying the significance of perfect declipper, even if I settle with Unchirp (to replace Vitalize) I will still put prefect declipper in the chain as first plugin with dequantization and pre-ringing killers.

Nobody helped my with any presets maybe I'll abandon the unchirp and go back to vitalize or maybe I'll play with for a little while. In any case perfect declipper is and will stay the primary choice for the Job.

Thanks again for taking interest in my query, your contribution is highly appreciated.

Edit: As suggested by the engineers in the thread, I've decided to drop the Unchirp. I'm experimenting with the transient shaper. I shell post the results when available.

 

Last edited: Sep 3, 2023

Unchirp is great for bird museum interviews.

at about the 20 minute mark the bird sounds come in.

 

Can you PM me the audio file?
I like messing around with audio restoration, I'd like to give it a shot.