Replay Gain Help / Basics

[Spirit Crusher]

Mods, feel free to move this if it isn't appropriate in "Music Corner"

I've been using Foobar2000 as my main media player and am getting comfortable with it. I'm now tentatively exploring Replay Gain. I've tried it on a Sabbath playlist, comprising the first six records, mix of pressings (Castle '86, Creative Sounds, Japan, needledrop), so the overall volume varies a bit.

Let's assume I know nothing.

I'm obsessed with correct tags, so that's no problem. I selected all, right click-->Replay Gain--> Scan selection as albums. OK, saved the info in the tags. I shuffled tracks and I noticed that the needledrop, which is .99 peak, is quieter, more like the Castles. That's great. The Creative Sounds self-titled comes on, and it's a bit louder. What's going on here? What should I choose in Playback mode? "Track gain" or "Album Gain"? I don't really understand this. Again, when playing multiple albums, what should the playback be--"album gain" or "track gain"?

Back to basics--what exactly do the "gain" values mean? Why negative values? For example, Death's Symbolic has album gain of -8 db. It's a loud CD, so I assume the lower the negative number, the louder the file?

The previously mentioned needledrop--I tried burning it with Replay Gain, album gain, no adjustment to pre-amp. The burned CD is quieter than original files--why is this?

Sorry for the rambling post. I've found various threads on HydrogenAudio and it just confuses me...I need "Replay Gain for Dummies"!

[Rick B.]

The album setting means that the relative loudness differences between tracks on the album is maintained - every song is given the same replaygain value - which is the value for the loudest track. The track setting means that all tracks are individually given replaygain values so that all tracks have the same perceived loudness.

Obviously, most critical listeners choose album gain as they want the artist's intentions to be preserved.

When playing the tracks you should again choose album gain if you want to use the values you already saved as album tags. The result should be that there is less variation between perceived loudness of your albums while still maintaining the relativity between album tracks.

In simple terms, Replaygain uses a maximum db value as a reference (-89db I think). A -8db replaygain value means that on playback the volume level will be reduced by 8db - quieter, in other words. A high negative value means the CD was mastered very loud and needs to be made quieter according to the reference level.

Most pop albums, newer ones for sure, and many older ones usually, will have a negative replaygain value - some releases, especially classical, may have positive values.

[Stefan]

In simple terms, Replaygain uses a maximum db value as a reference (-89db I think).I don't believe it works on the peak value per se. The 89dB is a sound pressure level value that's the default target. I forget the exact standards involved, but I believe it comes from or is based on a SMPTE audio standard for loudness levels in movie theaters.

That's one part of Replaygain, but there's also the notion of equal loudness curves. Certain frequencies contribute more to human perceptions of loudness than others, so material with more of these frequencies will be attenuated (or boosted less if the change is to be a boost) so that the overall perceived level is the same.

I've been using RG for over a year now and I'm amazed at how well it works at matching levels. It's almost as if it finds the vocal level, and focuses the adjustment on getting all vocals to sound the same. At times, when listening to mixed compilations, it almost makes them sound like they were recorded at the same time, in the same place, with the same levels. Hence, 1965 Beatles mix with 1972 Led Zeppelin and 2007 Annie Lennox yet all at the same level.

Obviously, if you use the album gain (sometimes called "audiophile") there will be more variations in track levels if the artist intended that. I create specific MP3 files of my CDs and needledrops to play in my little Sandisk pocket audio player (and lately WMA. It's not an archive quality format, but it's uses less space) and replaygain has been very useful.

I've also noticed that RG levels seem to correspond quite well to CDs mastered in the early to mid 80's before the loudness war began. In fact, the first thing I do with new CDs I get is rip them to my PC as lossless files and process the files with RG. I have a pro soundcard that's hooked up to my home stereo so for home listening, I play these (usually with Foobar2000, incredible piece of software). For the car, I have a bunch of rewritable CDs, and as I said above, I create mp3s/wmas for the Sandisk. Most new 2007 releases I've done this with have required average attenuations of -7 to -10dB. This of course can't help a squashed mix, but at least it makes it more bearable.

For the lossless files at home, I rip using album gain (the value is stored in the file but the data remains intact). For the mp3s, I actually apply the gain level to the file, and I use track gain for this because I want the levels to match. This never really becomes a problem unless I'm listening to two tracks from the same album in a row and one is radically different in volume from the other. The transition will be more obvious, but of course the levels will be very much the same.

http://en.wikipedia.org/wiki/Replaygain has some good info and links to other sites.

Regards,
Steve.

[Spirit Crusher]

Interesting guys, thanks...I think I'll stick with Album Gain instead of Track.
I'll play around with it more; I'm sure I'll have more questions.

[benintune]

I've been playing around with RG on the mediamonkey program. I have been using it on playback only so it doesn't change the actual file.

Is there a way to set it so it will attenuate the loud tracks but not boost the quiet tracks?

[Stefan]

Is there a way to set it so it will attenuate the loud tracks but not boost the quiet tracks?Not really, unless you manually remove RG data from the quiet tracks. If the tracks are scanned and their levels determined using album gain and you use the album gain playback settings in your playback software, the softer tracks will play softer the way the artist intended (of course, we shouldn't be slaves to that notion anyway).

One thing I've noticed with Foobar is that if you scan a group of files "as a single album" or as albums based on their tags (useful when scanning more files from several albums), Foobar calculates both the album and track gain values. So I have my Foobar set to playback using album gain but it's Convert function set to create files based on the track settings so that the MP3s I create all have roughly the same level.

[ckacosta]

MP3Gain uses the ReplayGain algorithms. Is there any difference between the implementation of ReplayGain in MP3Gain and Foobar? Will my files be tagged the same way? Is Foobar better than MP3Gain?

[Stefan]

I haven't used MP3gain, but if it uses the same algorithms, it should be the same. I recommend Foobar whenever I can because it's incredibly versatile, like a "swiss army knife" for audio, plus it's free!

[tps]

Whether to have foobar use "album" gain or "track" gain depends on how you're playing things. When you're listening to entire albums at a time, choose "album" gain. Usually the mastering engineer has taken track-to-track balance into account, and "album"; if you correctly tagged the tracks, all album gain tags should be the same for the album, thus the replay gain will be the same for all tracks.

OTOH, if you're listening in "shuffle" mode, where foobar is playing tracks from different albums, set it for "track" gain. This will adjust the volume on a track-by-track basis and attempt to make all tracks the same apparent loudness. It does a pretty good job. However, replay gain can't deal with everything. Say you've got a song that ends loud followed by a song that starts soft. Well, it may still be a jarring transition. But, in general, the world is a lot better with replay gain than without it.

[Spirit Crusher]

I've been enjoying listening to different albums with Foobar's "shuffle"-- I have a metal playlist with stuff from late 80s death metal (Obituary, Terrorizer, etc.) and more recent Napalm Death. Now that the relative loudness is similar, I can really hear how metal production has changed. The Terrorizer sounds nice and punchy and open; Into the Grave sounds "muddy" in a good way, but then Napalm's Enemy of the Music Business comes on, and even at the same overall volume level, I'm slammed in the face with a wall of guitars, and it sounds strange, like the guitars are "artificially" boosted or something. I looked at the Gain values, and Album Gain is about -9db, which seems to be a lot. Comparatively, Bolt Thrower's Realm of Chaos, the original 1989, has Album Gain value of -0.99! Replay Gain does make these buzzsawed, nuked records more listenable somehow.

[Stefan]

Replay Gain does make these buzzsawed, nuked records more listenable somehow.Yep, it's been a lifesaver for my musical enjoyment. Some stuff ends up sounding like it's been run through a cheap fuzz box. You really begin to realize just how badly mutilated the music really is, but at least it doesn't fry your ear drums.

[Liquid Snake]

Yep, it's been a lifesaver for my musical enjoyment. Some stuff ends up sounding like it's been run through a cheap fuzz box. You really begin to realize just how badly mutilated the music really is, but at least it doesn't fry your ear drums.

Indeed. The other benefit of Replaygain is, you don't have to go running for the volume control every time a "loud" CD comes on. The only time you have to touch the volume is if YOU want to, and not because of some disc that's been nuked to hell.

[hushypushy]

I love ReplayGain. Take this, loudness war!

I'm obsessed with correct tags, so that's no problem. I selected all, right click-->Replay Gain--> Scan selection as albums. OK, saved the info in the tags. I shuffled tracks and I noticed that the needledrop, which is .99 peak, is quieter, more like the Castles. That's great. The Creative Sounds self-titled comes on, and it's a bit louder. What's going on here? What should I choose in Playback mode? "Track gain" or "Album Gain"? I don't really understand this. Again, when playing multiple albums, what should the playback be--"album gain" or "track gain"?

Always Album Gain. Otherwise, inside albums, songs are gonna be really weird. For example, if you listen to Winds of Creation, Dance Macabre will be super loud compared to the rest of the tracks, and it's obviously supposed to be much quieter.

Some people recommend Track Gain if you're making a playlist--I disagree with this. In most albums, the tracks are different volumes; some are loud, some are soft. Using album gain, you can let the loud songs be loud, the quiet ones be quiet, etc. This is more of a personal preference issue, so I'll leave this one up to you.

Back to basics--what exactly do the "gain" values mean? Why negative values? For example, Death's Symbolic has album gain of -8 db. It's a loud CD, so I assume the lower the negative number, the louder the file?

The value is how much the file has to changed to meet a RMS value of 89dBFS (decibels full scale). The max is 106dB IIRC, so technically the highest value possible is -17dB. If you encode lossy, you can get higher (well, lower, like -20dB) values because so many samples clip. Merzbow's Pulse Demon is a good example, even at 320kbps, mine shows as -19.37dB with one track even hitting -21.

The previously mentioned needledrop--I tried burning it with Replay Gain, album gain, no adjustment to pre-amp. The burned CD is quieter than original files--why is this?

Probably because you have a negative RG value. It's making the file quieter. Maybe only a dB or two, but still quieter. Not many albums have positive RG values.

I would honestly not recommend burning CD's with ReplayGain. I suppose the common mentality around here is to put the least amount of resistance in the music, whether that be transferring recordings flat, using good components in your system, turning off EQ, etc. I don't feel comfortable doing digital gain adjustments to a 16bit file right before burning. But that just might be me, your results may vary.

Sorry for the rambling post. I've found various threads on HydrogenAudio and it just confuses me...I need "Replay Gain for Dummies"!

If you need any help, feel free to PM me or just ask in this thread. I think I have a pretty good grasp of ReplayGain, and HA can be confusing if you're not a super nerd.

Interesting side note about RG: quiet albums will sound louder. I love this. Loud albums obviously have less dynamic range, right? So when you put them side by side at the same volume, the more dynamic file will have bigger peaks, thus being louder. Yet another reason I hope every single day that something like ReplayGain will become standard on every audio playback device...

[Spirit Crusher]

I can't wait to try making a mixed CD with Foobar and Replay Gain. Foobar is my new best friend. It effin' rules!

hushypushy, thanks for the feedback! what do you think about mixed CDs with RG?

and you're right, quieter records do sound louder! I noticed this about the previously mentioned Bolt Thrower, which, by itself, is very quiet. And coming right after the -9db juggernaut, it was much punchier!

[benintune]

I've been playing around with RG for a few days now and have been having a difficult time with the settings. I have Audiomonkey, db amp and Foobar which all have RG and when I apply it I think it gets quiter than need be. What I'm trying to get to is where a non- compressed file will peak around -.1db and the loud files will adjust to about that level but what I think is happening is that they all adjust variably lower with only a few exceptions. What settings are you guys using that you are happy with?

[hushypushy]

hushypushy, thanks for the feedback! what do you think about mixed CDs with RG?

Depends on the application and the tracks used. Let's say you're making a mix with, say, some Decapitated songs (-11dB) and some Diament mastered Slayer (-3dB). It would be smart to use RG here, because if you crank up the Slayer, when it switches to Decapitated, the ~8dB jump is going to blow your head off!

Personally, when I make mixes, I don't use RG, but I do take the loudness of albums into consideration. I had a great metal comp (ugh, taken when my car was stolen) in which I ordered the album from best mastered to worst mastered.

Try experimenting and see what works better for the music you're using and the environment you'll be listening in, that's my best advice.

and you're right, quieter records do sound louder! I noticed this about the previously mentioned Bolt Thrower, which, by itself, is very quiet. And coming right after the -9db juggernaut, it was much punchier!

If you want a laugh, try using Track Gain (yes, Track Gain) and listen to the original Reign in Blood side by side with the remaster. Holy crap!!

[hushypushy]

I've been playing around with RG for a few days now and have been having a difficult time with the settings. I have Audiomonkey, db amp and Foobar which all have RG and when I apply it I think it gets quiter than need be. What I'm trying to get to is where a non- compressed file will peak around -.1db and the loud files will adjust to about that level but what I think is happening is that they all adjust variably lower with only a few exceptions. What settings are you guys using that you are happy with?

Of course they are all adjusting variably lower--all your CD's aren't the same levels, are they? ;)

Are you using Album Gain? Make sure you're using this and that you're scanning each album individually (either scan them one at a time or use the 'scan by tags' option). After this, all the albums should be approximately the same volume, with the less compressed albums being a bit louder than the more compressed ones.

Also, your volume level should be dropping noticeably, there's no problem there. What are your RG values? Keep in mind that -6dB is 50% volume, and many modern albums are -10dB and louder!

[Spirit Crusher]

(-11dB)
:eek:

[benintune]

Of course they are all adjusting variably lower--all your CD's aren't the same levels, are they? ;)

That's obvious one right? What I meant to say is even tracks that have no compression and aren't clipped are also getting lowered and I want those left alone or raised.

Are you using Album Gain? Make sure you're using this and that you're scanning each album individually (either scan them one at a time or use the 'scan by tags' option). After this, all the albums should be approximately the same volume, with the less compressed albums being a bit louder than the more compressed ones.

Also, your volume level should be dropping noticeably, there's no problem there. What are your RG values? Keep in mind that -6dB is 50% volume, and many modern albums are -10dB and louder!

I forget what RG values I'm using. I will check later this evening if I have time. One thing I noticed is the three progams that I have with RG all have different options on the settings...at least it appears that way.

[RichardL]

MP3Gain uses the ReplayGain algorithms. Is there any difference between the implementation of ReplayGain in MP3Gain and Foobar? Will my files be tagged the same way? Is Foobar better than MP3Gain?

I've been using mp3Gain (Track Gain to 92 dB) for years on my "All Standard Tracks" playlist, which currently has over 4000 songs in it. It adjusts the volumes so it doesn't blast one minute and then be okay the next. One problem I've noticed is that with louder CDs (1995-present, I think) since it can't really reduce the bass thump without reducing everything else, it doesn't. Even so, I usually don't have to change the volume on either my player or the playback system more than a tick up or down.

I also adjust the gain downward if, at 92 dB it is still clipped, by 0.5 dB at a time. Then, I save the gain to the file.

I don't use it on my albums playlists, which I rip separately. (Yes, I make work for myself.)

The only artist MP3Gain really doesn't work for is Laurie Anderson, especially United States, because there is an extreme volume range and a tiny dynamic range (if I'm using the right terms). I also have one song ("Rickover's Dream") by Michael Hedges for which mp3Gain can't determine the optimal dB level.

[sasha]

hi all,

i'm new to replay gain here but so far i'm loving what it's doing for matching volumes. one question, though: when replay gain raises the volume of an audio file, any chance that the higher volume will cause the waveforms to clip? (in effect, altering the original audio "picture" of the file?)

cheers :)