JohnSwenson wrote: > On the digital filter issue here is what can happen: > lets say you are feeding the ADC in the recording studio an analog > waveform in which the peaks are exactly at the level to produce a Full > Scale (FS) output. What happens when a sharp peak (say a piano key > pressed hard) hits inbetween the sample points? The numbers that come > out of the ADC are slightly less than FS, the sample time hits the > "skirts" rather than the peak. When these samples are fed to a DAC the > digital filter inside reconstructs the peak inbetween the original > sample points at exactly FS, the DAC handles that correctly and > everything is fine. > > But what frequently happens is the track gets processed and those > samples which were slightly below FS now get boosted so they are at > exactly FS. When THESE samples hit the digital filter in the DAC it now > produces a peak which is greater than FS. There are a few different ways > a DAC can deal with this. If it was not specifically designed to deal > with this issue that peak above FS will most likely wrap around and > become a FS peak of the opposite polarity, a short impulse as loud as > the DAC can produce, a REALLY REALLY bad distortion! It can clip the > value, this is not as bad since it is just chopping off the very peak > of the waveform, OR it can decrease the volume of the whole waveform > very slightly so it can properly reproduce these peaks above FS. > > The last option seems like a good way to deal with it, BUT the chip > makers don't like doing this, it means everything is slightly lower in > amplitude which decreases the overall SN ratio of the chip, and to a > chip maker that is the single most important spec to get as good as > possible. Doing this to one of their chips puts it at a disadvantage in > the marketplace. If every chip on the planet did this and did it by the > same amount, then it probably would not be an issue. But then you would > have massive creative specmanship going on. > > John S.
Good facts to know,thank you. So loudness war recordings do sound even worse with most DAC's :) Another solution may be recording engineers go back to the practice of leaving some headroom on the recording/master . User that are using smartgain and rg tags would not be affected . ------------------------------------------------------------------------ Mnyb's Profile: http://forums.slimdevices.com/member.php?userid=4143 View this thread: http://forums.slimdevices.com/showthread.php?t=97483 _______________________________________________ Touch mailing list Touch@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/touch
