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  #1  
Old 2019-03-05, 06:01 AM
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TheMysticMuse TheMysticMuse is offline
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Question Where to start with remastering/cleaning audio? (Need help)

Hey guys,

Is there anyone here or has any knowledge of cleaning up/remastering live recordings? Where the heck do I start? I wish there was a book called "How to remaster your live recordings for dummies!"...

As many of you may know I'm a serious Van Morrison collector, so I've listened to many different shows comparing the original masters to the remasters done by JTT, 4-EyedFreak, Acetboy etc. And some of these reworks are just brilliant, didn't know you could "restore" audio like that.

So what software is needed? I have the money so I can buy good products if that's what I need. Are there any good book/guide/PDFs to buy or read online that I can find somewhere? Would also want to know what all the terms that are used in mastering mean, like; gain, EQ, normalization, left-right channel normalization, RMS levels etc, and how these terms will alter the audio if you start messing around with these terms.

Just to show an example, I uploaded a Van Morrison acetboy rework today which sounds way much better than the original master. Here is what he did:

"This is a mono recording. On the original share the left channel is always louder than the right. The left channel is seriously compressed alsao. So I used the right channel to reconstruct this.
The original share is running too slow. After fixing that and trimming a little applause here and there this now fits on one CD. The show is now continousa, no gaps of any kind.

For an audience recording inside the huge Auditorium Theatre this sounds pretty darn good. The taper must have been on the floor somewhere. The vocals come through quite well. As do the instruments most of the time. When the music is soft and the crowd is quiet it's very nice.

Original share had a RMS level of -13.7dB
this now runs at -15.5dB"


What kind of knowledge is needed to do what he has done? Basically I need some advice where to start, some basic explanation of the terms that are used in mastering, the most typical faults that live recordings have and how to "fix" these.

Thanks for taking your time reading this wall of text. Hope everyone is having a great day!

Regards,
Christian from Sweden

PS. Since I'm a Swedish speaking viking my English sucks, sry about that.
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  #2  
Old 2019-03-05, 08:37 AM
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hendrixfan1995 hendrixfan1995 is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

The one thing you'll need most is willingness to experiment. And patience - you can't learn it overnight or by following a simple guide, and several tasks rely on brute force manual wok.
You need to know which problems can occur with old audio sources, how to spot them and how to ameliorate or fix them. You need to look at the audio samples (audacity is good enough for that), and become familiar with a good spectral editor like Izotope RX.
It is easy to slap on some NR and repitch something, but if you do so without consideration, you're not doing any good. That's the pinkrobert way of remastering, and it is rightly outlawed. It's not that all remastering is entirely bad and evil (which is the ridiculous attitude presented on this forum), but you have to decide what each source needs. If you take great care, you can really work miracles with bad sources.

Non-inclusive list of issues, roughly in ascending order of difficulty:
- EQ
- phase mismatch / azimuth
- hiss / noise
- dropouts
- clipping
- distortion
- speed issues, wow & flutter
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  #3  
Old 2019-03-05, 04:43 PM
acetboy acetboy is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Where to start? All of those things you're asking questions about can be googled.
I'm sure you could spend hours/days reading things and looking at You Tube videos.
Which is all a good place to start.

I get the impression you need to learn a lot of basics about audio in general and digital audio in particular.

I bought my first computer in 2005. That's kind of late.
I also bought Pro Tools LE on the same day from the same dealer.
I had been spending years reading music/instrument magazines and books.
I already had spent years owning audio equipment like keyboards and mixers and various
types of recorders.
I had several samplers one of which my Kurzweil showed a small waveform in it's screen for editing.
I read about Pro Tools for a number of years before I bought that first computer.
So I knew basically what I was going to do even though I had never done it. lol

My idea was that I was going to be creating music of my own. LOL Big ideas. LOL
Well I did from the start began recording my friends who have a punky garage band.
That helped.

And soon after I got that computer I did figure out all about bit torrent and all of these sites
we all love.

And pretty quick I did discover that much of the music that's shared be it old recordings that
have been shared for years and years or new captures that people were putting up, much of
this music has various issues that could be corrected.

I got the rudiments down fairly quickly but then I spent several years developing the techniques that I use. And then several more years to get half-way good.
And I think I'm getting better all the time, or I'm trying to anyway.

So you need some decent monitors/speakers. They don't have to be huge or incredibly
expensive but you have to learn what they sound like. Listen to lots of your favorite CD's
legitimate releases. And it helps to put your favorite music from those cd's into an audio editor and learn that way what a waveform looks like. Learn what spectral views of legitimate releases look like. Learn what the FFT views of your favorite music looks like.
Your masters/remasters should look much like a legitimate release looks like.

Audacity is a good app to start with, it's free and there's lots of info on it available.
I've recently discovered another free app called ocenaudio. I really like that one for it's
FFT views and spectral views.

Learn how to use low pass and high pass filters. If you apply a low pass filter at 120 Hz
that will cut off everything above that point and you'll just hear the low end.
And you can then look at the low end only, see what the waveform looks like.
Maybe the first half of a show has a good strong low end but then the latter half
suddenly loses the low end. You can do the same with a High pass filter at 8000 Hz
and see/hear nothing but the high end. What's going on up there? Is it strong or lacking?
Is one channel louder than the other?

And then by using low and high pass filters together you can isolate various frequency bands
and see what's going on there say in the upper mids.
And you might see/hear that even though the low end is fine phase wise up here in the
upper mids it's gone out of phase. Very common thing with external microphones.

So that's all I got now, good luck.
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  #4  
Old 2019-03-05, 08:04 PM
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dorrcoq dorrcoq is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Good stuff acetboy, except for the part about wanting your WAV forms to look like those of commercial CD's. Those are so severely compressed and with limited dynamic range, I know that's not what I strive for in a show I work on.
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  #5  
Old 2019-03-05, 08:19 PM
acetboy acetboy is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Quote:
Originally Posted by dorrcoq View Post
Good stuff acetboy, except for the part about wanting your WAV forms to look like those of commercial CD's. Those are so severely compressed and with limited dynamic range, I know that's not what I strive for in a show I work on.
Right, we don't want our waveforms to look like super compressed/limited releases. No, mine never do.

What I was trying to say is that you can learn a lot by looking at spectral
and FFT views of legitimate releases. The waveforms will only tell you; 'don't
look like this'.
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  #6  
Old 2019-03-06, 10:57 AM
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TheMysticMuse TheMysticMuse is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Thanks everyone for your input, really appreciated. Seems like it's trial & error that is the right thing to do. A book/online guide won't make you a pro, but at least it gives you something to stand on. I will try searching around the web.

Does anyone of you mind showing me an example of a show that you've remastered/cleaned and tell me the problems the original recordings had, how you managed to hear/see this problems and what you did to fix these and how you did it.
Then I can use your examples to practise, and try to make it sound as good as yours. Perhaps you could upload a track in its original form here on this forum + the remastered one.
WeTransfer is free and easy to upload: https://wetransfer.com/

This way I could study the difference between the original FFT view, spectral view, right-left problems, eq, applause etc and compare it to the remastered ones. For studying purpose.
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  #7  
Old 2019-03-06, 11:25 AM
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GRC GRC is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Download Audacity for free and play with it...
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  #8  
Old 2019-03-06, 04:47 PM
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dasmueller dasmueller is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Quote:
Originally Posted by GRC View Post
Download Audacity for free and play with it...
Be sure to make copies to play with and keep the original.
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  #9  
Old 2019-03-07, 04:29 AM
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hendrixfan1995 hendrixfan1995 is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Here's an example of a show recorded from a TV broadcast in 1972:

https://we.tl/t-r7lE78AjGR

From the release notes:
Quote:
This inline recording was captured from a TV broadcast. Even though the music rolls off at 8 kHz, the recording quality is so clear that it has the original PAL sync tone almost continously throughout at around 15kHz. This pilot tone can be used to lock the recording to its original speed and pitch, exactly as broadcast. With the PAL sync tone restored to its proper 15625 Hz, all tape speed drift (wow & flutter) is now corrected.

On top of Kneesfudd's Mk1 restoration, a few more more dropouts and clicks have been fixed for this version. Three sub-second tape defects that could not be restored from this tape alone have been patched in from two alternate, incomplete sources: fixes for tracks 1 & 2 come from the old boot version; track 13 has a segment from from "Stephen Stills - Wooden Music Compilation" (assembled by Eddie Hill) spliced in. Some annoying amplifier buzzes and feedback beeps have been removed from the spectrum.

The EQ has been restored with an EQ curve averaged from several differential EQ samples (the final EQ curve is included as an audacity XML file for reference). The main source (Kneesfudd's Mk1) is less compressed than the boot version, so the original dynamics are preserved. The acoustic songs are, in fact, not significantly cleaner on the boot version - that seems to be an artifact of signal compression and some overtone distortion. I should also note that the boot is not in simulcast stereo (ie. two discrete channels), but merely mock stereo with different equalization on either channel.
Here's another one - this only removes the cyclic tape wow effect (listen with speakers, not headphones, to make the difference most perceptible). It's about the most difficult audio problem you could attempt to fix:
https://we.tl/t-opTgcd6CM6
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  #10  
Old 2019-03-07, 01:34 PM
TheMysticMuse's Avatar
TheMysticMuse TheMysticMuse is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Quote:
Originally Posted by hendrixfan1995 View Post
Here's an example of a show recorded from a TV broadcast in 1972:

https://we.tl/t-r7lE78AjGR

From the release notes:


Here's another one - this only removes the cyclic tape wow effect (listen with speakers, not headphones, to make the difference most perceptible). It's about the most difficult audio problem you could attempt to fix:
https://we.tl/t-opTgcd6CM6

Thank you so much. This is what I wanted. Interesting to hear the differences and what a proper made remaster can do to a tape with major problems. Unfortunately my speakers are kind of broken so I'm using headphones atm (good ones though). I'm going to order new speakers soon. Do you have any recommendation for good speakers to have connected to your PC?
It went from audio remastering to speaker recommendations

Thanks again everyone for the input. Appreciate it. I already have audacity so I'll be messing around with it. Already found a great guide/tutorial about cleaning up/remastering. Don't know what term to use. What has to been made for someone to call it a remaster? some recordings I have have comments like "audio rework, audio cleaned up etc".
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  #11  
Old 2019-03-07, 02:39 PM
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hendrixfan1995 hendrixfan1995 is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

The common idea that you need high end speakers for all of remastering work is perpetuated by many who consider themselves "experts", but it's simply wrong. Generally you can use crappy headphones as long as you have adjusted to them and know what good recordings should sound like on them. When I'm on the move, I regularly use 10€ in-ears, but I have adjusted to their frequency & amplituded response so that works just fine. I generally base most of my crucial remastering decisions (EQ, speed) on hard science rather than my (subjective) sense of hearing, so my ears are mostly used for "double checking". I use my eyes at least as much as my ears for audio cleanup, because I always deal with spectrograms.

I only recommended using speakers for that very specific example, as tape wow effects are more perceptible in a listening environment with room reverb. Your ears pick up the direct signal from the speaker mixed with room reverb (it becomes "wet"), and the wow & flutter introduces interference artifacts that your brain decodes to "hey, something is wrong with this sound". If you use headphones, your ears pick up "dry" sound and it has to rely on pitch variation alone to detect the issue.
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  #12  
Old 2019-03-09, 10:59 AM
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TheMysticMuse TheMysticMuse is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Quote:
Originally Posted by hendrixfan1995 View Post
The common idea that you need high end speakers for all of remastering work is perpetuated by many who consider themselves "experts", but it's simply wrong. Generally you can use crappy headphones as long as you have adjusted to them and know what good recordings should sound like on them. When I'm on the move, I regularly use 10€ in-ears, but I have adjusted to their frequency & amplituded response so that works just fine. I generally base most of my crucial remastering decisions (EQ, speed) on hard science rather than my (subjective) sense of hearing, so my ears are mostly used for "double checking". I use my eyes at least as much as my ears for audio cleanup, because I always deal with spectrograms.

I only recommended using speakers for that very specific example, as tape wow effects are more perceptible in a listening environment with room reverb. Your ears pick up the direct signal from the speaker mixed with room reverb (it becomes "wet"), and the wow & flutter introduces interference artifacts that your brain decodes to "hey, something is wrong with this sound". If you use headphones, your ears pick up "dry" sound and it has to rely on pitch variation alone to detect the issue.


Thank you so much for sharing your knowledge to a noob like me. I've been messing around the last couple of days in Audacity, so fun!!!
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  #13  
Old 2019-03-09, 11:36 AM
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hendrixfan1995 hendrixfan1995 is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Quote:
Originally Posted by TheMysticMuse View Post
Thank you so much for sharing your knowledge to a noob like me. I've been messing around the last couple of days in Audacity, so fun!!!
You're welcome. I have written a nice EQ matching tool to complement audacity's built-in EQ; it is very useful if you can get over the fact that you have to install some python dependencies from the command line...
How to Use
Download & Installation
This is what I used to restore the EQ on the first sample I posted a few days ago.
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  #14  
Old 2019-03-19, 05:42 AM
metalurg metalurg is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

Like mentioned above, many factors to take into consideration.

What kind of audio source you are working with >> Linage >> Generation >> Audio Cassette / LP / Digital Files etc...

Too much "remastering" has also "killed" many great recordings..."Donīt fix what is not broken"...

Also many people/tapers/traders forgets about the playback-options...Will you listen on headphones, on your speakers, on a small cheap portable CD-player...? This will have affect on how the "final sound" sounds in the end...Crap and bad sounding "playback"-options will not increase the "remastered" product...

The ultimate source is a source that is recorded well from the start...some sources can "use" some "remastering", yet itīs a thin line between updating a source with "remastering" and "destroying" the dynamics...

With dynamics we usually mean that most people do the general fault of raising the "treble/highs" too much to make the recording "brighter and sharper"...yet many has failed and all dynamics (mid-range / bass-range) is lost and gone.....

Best to think like this when remastering audio:

- Keep a good balance between >> Treble >> Mid >> Bass-frequencies.

Itīs not which audio software you use...itīs mostly about the person doing the "remastering" and your ears...also ask what the purpose is of each "remastering"...(!)
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  #15  
Old 2019-06-10, 09:48 AM
MC5tooge MC5tooge is offline
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Re: Where to start with remastering/cleaning audio? (Need help)

I'm using Adobe Audition for the processing I do on the shows I tape.(Tape wow and flutter is not an issue on these, as I record on a Zoom H4, and another hard disc recorder and a HiMD Minidisc before that.)

I do actually have a fairly standard procedure.
1) Process at as high resolution as possible. On my system this is 32 bit floating at 96khz.
2) Frequency band split your master into five files, each for the different frequencies.
3) Add these five files and the untouched master into the audio mix so you have six different channels.
4) Leave your master untouched.
5) Play around with compression, dynamics, dynamics processing etc. in the five split channels to optimise each frequency. Different frequency channels need different boosts- bass my need fattening up - snares may need a bit of air etc...
6) Play with the setting on the sliders to get it to sound right. Most of the mix should be the original master file. The other channels will just work as a kind of boosted form of EQ adjustment. If you've done it properly, you'll be adding extra clarity to the various instruments and voice. Sometimes it can be a good idea to add the mid-frequency channel twice and adjust one for guitar and the other for voice.
7) POSSIBLY use the mastering preset in the output channel.
8) Downmix to stereo mix at desired resolution.

Every recording I've worked on using this method has ended up sounding a lot better, yet without adding audible distortions.

I play back on speakers and headphones during the mixing process and after mixing play back on another system. If it needs redoing I redo it.

Last edited by MC5tooge; 2019-06-10 at 09:58 AM.
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