i've often......... imported a full commercial song to an audio track in my daw, loaded up a good quality analyzer and its been clipping? i'm probably explaining this badly. basically how can a digital audio file be more than 0db?
there's a lot of compression on commercial tracks. a lot. a whole lot.
so, when a typical DAW imports a heavily compressed track ( that's whacked up as close to 0 db as possible ) .... the resulting digital audio file clips ....
A lot of commercial relleases clip with digital overs, check out Metallicas Death Magnetic !
It's acceptable nowdays, sounds like shit if played on a nice system but deemed an acceptable trade off in order to get the tracks as hot as they are level wise.
a) The audio may be peaking exactly at 0dB, and your DAW is set to shows clips when audio reaches exactly 0dB, rather than specifically over 0dB. (Pro tools is like this). This is why I usually set my limiters to -0.2.
b) intersample peaks. No single peak is passing 0dB, but when the samples are being played back you can get intersample peaks where the singal kind of makes up for something that isnt there, when moving between two samples, which can cause clipping.
Not many limiters can cope with intersample peaks, Sonnox is one I can think of.
I cant explain it very well, but this guy can...
Your audio peaks at 0 dBFS, or full scale, yet there might be even higher peak levels lurking between your samples. Clipping and distortion is the sure and certain result, yes?
There is no doubt that audio is full of folklore and old wives tales. Sometimes it is difficult to know whether advice is good, or whether it's just something that someone dreamed up out of thin air.
The fabled 'inter-sample peak' is a good example. It's like the unicorn - some people will swear on oath that they have seen one. But most of us haven't, and however much we might wish they existed, we really don't believe in them.
The concept of an inter-sample peak is straightforward. Take two adjacent samples, both at absolutely the maximum value they can possibly be.
Between them is an even higher level, but it doesn't actually exist and is not represented by any sample.
Therefore by this logic, inter-sample peaks should not exist. But they might. Let's see how...
Suppose that the level just before the first of the pair of peak-level samples is rising very rapidly. And the level after the second peak-level sample descends very rapidly.
Some processes work on the rate of change of a signal, not so much on its absolute level. So if a signal is showing all the signs that it might breach 0 dBFS (absolute peak level), then even though it actually doesn't, the process might treat it as though it does, and attempt to produce an output that really does try to breach 0 dBFS.
The result is clipping, and therefore distortion. It can happen in a plug-in, or in the digital-to-analog converter.
Personally, although I don't believe in unicorns, I do believe in inter-sample peaks. More research is definitely necessary on their detection, and how plug-ins and converters can be designed to handle this phenomenon gracefully.
CD players and DAWs reproduce the waves as going over 0dBFS but this isn't the case. It is just interpolation and intersample peak issues that vary widely across systems.
Master at -0.3dBFS and you'll have no* issues.
Ignore commercial CD releases when importing them - just take the fader down -.5 dB and you'll have no "clips".
*this may yet cause a problem, but right now there is none that I'm aware of
audio files clipping?
Reply With Quote