If you're aiming for 99 dB you're probably asking for trouble, but mp3gain stores Undo info in a tag to let you recover and also lets you apply a fixed gain (in 1.5 dB multiples) so you could adjust by -6.0 dB if things were too bad. Obviously you don't use Soundcheck on these files in the iPod, but if you change the files, you may need to removed them from iTunes database then add them back to refresh any changes you make.

Sure heavily dynamic-compressed tracks like most of the last few years will be unaltered, but most people find that 92-94 dB is about as far as they'll go, and not often suffer from noticeable clipping distortion because of more dynamic music.

Clearly you aren't getting enough volume from your iPod. Another solution is to stick to 89 dB and over-ride the volume-limiter used to protect you ears (at your own risk!) - this limiter is included in iPods sold in Europe and some other regions. This blog post offers one solution, namely to run goPod every time you update your iPod firmware (if your iPod version is supported), which will remove the artificial volume control limit. I suspect iPods are configured for the "highest common denominator" - i.e. the most loudly mastered CD tracks in existence - to protect ears, but that's no use for some noisy environments or for low sensitivity headphones.

Anyway, just bear in mind that it's at your own risk.

Well, I was thinking of just getting a baseline of around 99db, so the majority of my tracks won't be altered... much. Some though will change as much as 25db, but this is hardly the norm.

Anyway, a quick question - If I adjust a track once, and then adjust it again, what is the end result if I select "Undo Gain Changes?" Will it revert the mp3 back to the last change only, or back to its' original pre-tagged mp3gain setting?

Should I just select the "Don't Clip When Doing Track Gain" option instead? Is this actually worthwhile doing at all?

Quote from: HollowPoint on 2007-09-02 14:26:49

Should I just select the "Don't Clip When Doing Track Gain" option instead? Is this actually worthwhile doing at all?

Well setting a very high target gain and then selecting that option is going to give pretty mch the same result as applying maximum "no clip" gain to each track. The problem with this is that it will defeat the original purpose of making the percieved loudness of all tracks the same or similar.

no, don't do that... the problem is that MP3Gain will only adjust in steps of 1.5dB each song - that means if you adjust the songs of an album too high or too low, they might show a big difference in volume. Once I did this with "Depeche Mode Playing the Angel" that is a ultra-compressed record on 99dB all tracks. I did an albumgain close to 89db bringing most songs down in -10dB. For my surprise track 2 was much much lower than the 1st and the 3rd, I assume that amounts of calculation and the limitation of 1.5db steps created an issue where a song can end up actually a bit lower than the "intentional loudness" from the source. For example: Two songs have to be brought exactly down to -9dB, but because of the 1.5 limit, one of them might go "unexact" and be adjusted to -10.5db. You get the idea?! But at the same time, those two songs would adjust fine if an amount of -3.0 was applied to them, because both would drop to -3.0dB. I never used MP3Gain with that adjustment again. Now I only adjust the minimum necessary to not show Y, or not clip.

Clipping start usually at 93-94dB in most albums. Albuns with 94dB will have some clipping tracks but not others. Albuns like the ones released by Oasis are 100dB and thus all songs clipping. 89-90dB is just a safety margin.

I don't use mediamonkey but you can replicate those mp3 and mess with a couple of them to test this in practice. (I only use foobar)

"Now I only adjust the minimum necessary to not show Y, or not clip." I don't follow you.

if you're into albums - lower them in 1.5dB steps until no "Y" shows in any song. *downside: some albums will be louder, other lower, but none will clip.

if you're into tracks - you can apply 89dB in all of them - except for those less than 89dB... some 87dB track may clip going to 89dB - recommentation don't touch these ones. *downside: you lose the album loudness intentional consistency: eg. some tracks intentionally done to sound quieter than others.

if you want perfect REALLY perfect syncronism and pass beyond the limitation of 1.5dB through the albums, then the best thing to do is to re-rip these albums from lossless source BUT with ReplainGain Album already applied into them (foobar would do), that way you can make all albums perfectly sound around 89dB with their loudness consistency. *downside: you make your tracks lossy for a second time, since you are removing gain from it.

the fourth option is to do the same thing above but with MP3Gain. *downside: because mp3gain adjusts gain in steps of 1.5dB, the more adjustment, many songs that are ought to be quiet will be much more quieter than it was intended.

whatever is lower than 89dB is probably NOT clipping, you shouldn't even touch these ones! unless they're part of an album in which other songs are much louder and you want to keep a consistency lowering the whole album at let's say -3.0dB.

greynol is right - it's difficult/impossible to hear the clipping. I stopped dealing with MP3Gain once I knew there's no way to make a destroyed record to sound better.

1) Yes, this is part of the loudness race. Today CD's are mastered to reach the full digital scale, in MP3Gain that would be volume 100.0.

2) They can be audible in the MP3 file and in the SOURCE/WAV file. "Californication" from Red Hot Chilli Peppers is an example of that. The record is completely destroyed, when you rip to MP3 you inherit that destruction. But there are loud CD's that are not so bad. I have middle 90's CDs that some songs are clipping but it is no more than 100 samples on the song. In this case, shouldn't be audible.

(Even though MP3Gain will detect the faulty peaks).

There are cases in which a bad encoder will introduce MORE clipping peaks into the encoded file.

3) As far as have been discussed in HA, no one can save a clippressed record. I've seen techniques to "guess" what wave peaks were, but they are nothing more than normalization. The only way out is the remasterization of every loud CD out there. But lowering the volume with MP3Gain or Wavegain process you just lower the volume - but the clipping will be there.