In article , Arny
Krueger
wrote:
"Serge Auckland" wrote in message



Consequently, we never experienced this sort of problem, and it was
then acceptable for digital players to clip at just over 0dBFS, albeit
for the wrong reason.

Thing is, these FS overs are very rare.

Depends on the context. I have found various commercial CDs that generate
excursions above 0dBFS. In some case, on many occasions during the CD.
However these are almost all rock/pop music CDs. Much rarer with classical
or jazz in my experience. The difficulty here is checking enough CD issues
to results that have any statistical meaning, though.

As Jim says, this might account for why some CD players sound
different to others.

I doubt that. First, you have to find the good CD players that actually
do sound different from others.

At present that is the unanswered question which would need testing in this
context. There are CDs that generate the excursions, and others don't. I
have also see test results which show that different players can give
visibly different results on something like a scope when given 0dBFS
material. But have no evidence that this leads to audible differences.

There have been comparisons where the players seemed indistinguishable.
That might mean this doesn't matter. But because of the above we'd now
really need to check what CDs were used as source material, and if they
produced any 0dBFS excursions or not. And if they did, the effects might
vary from case to case, which makes this difficult to track down, except in
terms of a generalisation like that is 'usually' has no audible effect, or
whatever...

FWIW I don't yet feel any urge to change my DACs despite having some reason
to suspect they can't cope with the possible excursions without some amount
of waveform distortion. Simple reason being that they produce fine results
to my ears, and I've not yet noticed any problem when listening.

But we could null out all such concerns if the bods at the commercial music
companies simply avoided clipping the CD material and kept the level down
so that no 0dFBS excursions could be required on replay.

There is a supreme irony here that all CD players *would* sound the
same if CDs were mastered properly. Ah well....

Since I generally record with lots of headroom, the problem of FS
overs takes on a different form. I end up with recordings that have
very infrequent excursions that are 3-4 dB above the norm. If they
weren't there, I could up the average level of the recording by 3-4 dB
without clipping. Since my distributed recordings are typicaly
uncompressed, I'm already producing recordings that sound far softer
than most commercial releases.

I find much the same when doing home recordings, but it does not matter as
I am not trying to get anyone else to listen to the results. So can just
turn up the replay volume control a few steps. But as you say, this does
tend to make even more obvious just how loud many commercial CDs are!

Slainte,

Jim

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