Does anyone have any ideas on what a gain of 0dB in Volume Analysis represents?

[s7jones]

Hi everyone.

I've been having a look at normalizing the loudness of my music files recently.

From the following pages:
https://en.wikipedia.org/wiki/ReplayGain
http://wiki.hydrogenaud.io/index.php?title=ReplayGain
http://wiki.hydrogenaud.io/index.php?title=ReplayGain_1.0_specification

I've come to understand (rightly or wrongly):
- That the conventional/default recommendation of ReplayGain was 89dB(SPL?), -14dB, or -14LUFS. (I'm sure these three values are not entirely equivalent but it appears like a lot of the talk surrounding these values treats them as analogous under normal conditions). Which came from work used to calibrate audio level in movie theaters (SMPTE).
- That an updated recommendation included was 86dB(SPL (ReplayGain proposal and SMPTE RP 200:2002), -17dB, or -17LUFS.
- That the most up to date recommendation (EBU/R128 - included in lib1770 which Musicbee uses) was 80dB, -23dB, or -23LUFS.
- This MusicBee forum message (http://getmusicbee.com/forum/index.php?topic=10394.msg73925#msg73925) suggests that RG1 and RG2 are 83dB.
- Yet the website referenced in the quote Zak replies too (http://wiki.hydrogenaud.io/index.php?title=ReplayGain_2.0_specification#Reference_level) suggests that RG2 is -18LUFS.
- The lib1770 documentation (http://r128gain.sourceforge.net/#usage - bullet #3) suggests that the "most wanted" profile is -18 LUFS.

So my best guess would be that- the reference value of 0dB in Volume Analysis (MusicBee 2.5.5606) corresponds to:

* -18LUFS, which I am calling analogous to 85dB(SPL?) or -18dB. *

_____

Is that what other people understand to be the case? Have I made a mistake?

I'd like to know what you have to say. Cheers.

[Alumni]

Hi, I'm not entirely sure about that, but I can tell you that with a volume adjustment of -6dB I almost never have positive (album) gain with my library, and I listen to all kinds of genres including jazz and classical.

[redwing]

I don't know where you got those numbers, but I think MB's target loudness both for RG1 & RG2 is 89 dB or R128's -18 LUFS, which is the same as foobar.

[s7jones]

Thanks for your replies.

I don't know where you got those numbers, but I think MB's target loudness both for RG1 & RG2 is 89 dB or R128's -18 LUFS, which is the same as foobar.

As far as I understand one unit of LUFS is equal to one dB. This would mean that for a target loudness of 89 dB(SPL) would give you a headroom of -14dB / -14LUFS, and if you were working with a headroom of -18dB / - 18 LUFS then the target loudness would be 85 dB(SPL).

I agree that's it is likely to be one or the other of those settings though. But I guess it will depend on which parameters MusicBee is running lib1770 with.

Source
http://www.tcelectronic.com/loudness/loudness-explained/ - "one unit of LUFS is equal to one dB."
https://en.wikipedia.org/wiki/ReplayGain#Target_loudness - "The target loudness of ReplayGain utilities is 89 dB sound pressure level. The SPL reference comes from a SMPTE recommendation used to calibrate playback levels in movie theaters. A more common means of specifying a reference level is relative to a full-scale signal. ReplayGain nominally plays at -14 dB relative to full-scale leaving 14 dB of headroom for reproduction of dynamic material."

[redwing]

http://wiki.hydrogenaud.io/index.php?title=ReplayGain_2.0_specification#Reference_level

"RG1 is calibrated to a pink noise reference signal with a RMS level 14 dB below a full-scale sinusoid. This reference signal is used to establish a reference level. ReplayGain will apply no gain or attenuation to the reference signal or any program material which has the same loudness measurements as the reference signal.
BS-1770 defines a loudness scale for program material. The units of BS.1770 loudness measurements are in Loudness Units [relative to] Full Scale (LUFS). LUFS can be treated like decibels.
The loudness measurement of the RG1 reference signal is -18 LUFS. In order to maintain backwards compatibility with RG1, RG2 uses a -18 LUFS reference."

[s7jones]

Thank you redwing! That helped a lot, and will hopefully clear up any confusion for future googlers too.

[hiccup]

And to end any possible doubts about the results of MusicBee's implementation of RG128:
I ran several sorts of audio (classical, rock, spoken word) through MB's volume normalisation with setting the slider to '0dB', and these are some representative results. (perfect -18LUFS)





Yet I am afraid all above technicalities might also confuse many new users, so it might be sensible to summarize a little bit:

Setting the slider in MusicBee to '0' will indeed roughly match the old ReplayGain1 default value.
So the answer to your question in my opinion would be:
The 0dB position mainly represents and suggests some compatibility with an old standard.

The currently implemented R128 algorythm is yet way more sophisticated then the old RG1, giving far better results for all sorts of music, audio books, movies/commercials, etc. etc.
In broadcasting nowadays the advise is usually to aim for the region of -23LUFS.

So be aware that the '0' position in MusicBee is (in my opinion) not the advised setting if the rest of your audio chain and media are up to it and are set up well.
Therefore I personally would advise a setting of somewhere in the region of -5dB.
(apologies for repeating myself: http://getmusicbee.com/forum/index.php?topic=10394.msg73947#msg73947)

[s7jones]

Thanks hiccup, I can understand why it's easy for people to spread misinformation about audio - it's difficult and nuanced! (I'm talking for myself there.)

(apologies for repeating myself: http://getmusicbee.com/forum/index.php?topic=10394.msg73947#msg73947)

Thanks for replying - the clearer it is the better for me and future readers!

My current understanding
- The Volume Analysis at the 0dB setting represents -18LUFS.
- This setting uses the newer R128 algorithm running in compatibility mode for ReplayGain v1.
- That in this case -18LUFS might not also mean -18dB.

Cheers.

[hiccup]

What is making this a complicated matter is the fact that we are trying to catch mostly subjective matters with absolute numbers here.

The purpose of algorithms such as ReplayGain and R128 are to try and find an average perceived loudness.
Perceived by humans...
So, how loud would you as a human perceive a 20 seconds commercial? How loud would you as a human perceive a classical music track of 20 minutes? How loud as a human would you perceive a spoken word book, or a complete movie, etc. etc.
I would even imagine that a classical music lover would perceive an AC/DC song louder than a rock fan. And vice versa for a rock fan listening to Ligeti.

So that is where these algorithms step in, they all try to achieve some model of the average human perception of loudness for all this different content.

The new algorithms compliant with EBU R128 do this very differently and a lot better and smarter than the older RG1.
So there is no way you could get the same results between these two.
In MusicBee the R128 algorithm is not running in some 'compatibility mode' as your wordings, but only the '0dB' position somewhat resembles the striving for 89dB of the old RG1 algorithm.
But with this 0dB setting, a lot of music tracks will have clipping (digital distortion), since tracks with a low average perceived level, but with a few dynamic and loud peaks (some classical music by example) will have their overall level amplified to meet a higher average perception, bringing the peaks above the 0dB level, and introducing distortion.
(but that is probably a topic for another topic).

[MickyD]

Originally, Replay Gain, as proposed by David Robinson in 2001, was designed to avoid of continuous adjusting the volume of a music player.  His original proposal was that the perceived loudness was to be 83 dB.

ReplayGain, bought a change in the in the value of the perceived loudness to 89 dB.  The reason for the increase was to accommodate the needs of the film industry.  MB's sliding scale has ovecome the need for this change.
A more full description is here ( https://en.wikipedia.org/wiki/ReplayGain#Target_loudness )

Therefore, using “volume analysis” within MusicBee the “0” value, I would imagine the target value of 89 dB is achieved.  However; with MB’s sliding scale more than just the above-mentioned levels; it is therefore a matter of personal choice.

The higher the ReplayGain, the greater the opportunity is for “clipping” to be allowed, but MB allows for that if you tick the warning box.  Although “clipping” can ruinous to a sound, it need not be.  It is dependent on the way that CD has been Engineered and the simple fact that the human ear does not/cannot detect either an increase or decrease in  “sound pressure” of approx.75 dB.  ( http://www.dspguide.com/ch22/1.htm ) paragraph 8

I hope this is of use, if not already answered
Mick

[redwing]

 His original proposal was that the perceived loudness was to be 83 dB.

ReplayGain, bought a change in the in the value of the perceived loudness to 89 dB.  The reason for the increase was to accommodate the needs of the film industry.

The adoption of 83 dB as the reference level in the original proposal was based on the long-standing practice of the movie industry. That's what your source means.

[hiccup]

Therefore, using “volume analysis” within MusicBee the “0” value, I would imagine the target value of 89 dB is achieved.  However; with MB’s sliding scale more than just the above-mentioned levels; it is therefore a matter of personal choice.
I hope this is of use, if not already answered
Mick

Dear Mickey,
I am sure your intentions are well, but it seems you are mostly talking about the old ReplayGain.
MusicBee uses 'EBU R128' for a while now.
You also seem not to have read my contributions to this topic a few days ago (messages #6 and #8), explaining the differences between RG dB's and EBU's LUFS, and explaining 'the human factor' in this matter.
Therefore I am sorry to say that I feel that your posting might be adding some confusion again, instead of clearing things up for other users.

[MickyD]

Thanks for guidence hiccup
I did read the replies and felt they werd too technical.  I know appreciate why
Mick

[hiccup]

Thanks for guidence hiccup
I did read the replies and felt they werd too technical.  I know appreciate why
Mick

No problem Mick,
Let's just everybody read and learn what they want to read and learn.
Enjoy!