mulletchuck
Well-known member
http://www.soundonsound.com/sos/jun10/articles/masterclocks.htm
please discuss!
please discuss!
MikoKensington said:I'm not sure I get behind this article as a definitive test for clock performance, however. Am I wrong in thinking a clock would be better tested with multiple tracks of high sample rate audio instead shooting through 1 tone at a time? Perhaps, using different clocks on a mix, and using null testing to observe any differences?
MikoKensington said:Am I wrong in thinking a clock would be better tested with multiple tracks of high sample rate audio instead shooting through 1 tone at a time? Perhaps, using different clocks on a mix, and using null testing to observe any differences?
Andy Peters said:Once the tracks are captured, the ADC clock is irrelevant. The mixing in the DAW is not affected by, and has no effect on, converter clocking. Your proposed test won't prove anything.
-a
jdbakker said:What exactly would that show that you don't get from a high frequency single tone test?
MikoKensington said:Sorry if I don't understand guys. So when using AD/DA converters to patch in analog inserts in real time (delay compensated) on a mix, and using a DA for monitoring, the clock is irrelevant?
MikoKensington said:And to JDB, you're right. My test wouldn't "show" me anything. But I also don't record music comprised of single high frequency tones. So that illustrated test doesn't "play" me anything.
Nevertheless, these tests are valid as can be. We all know that music is complex, but we also know that it is pertinent to consider it as a sum of simpler tones; although a single-tone test won't permit evaluation of artefacts that happen in the presence of complex tones, it is very often significant enough to trace some problems. When a unit passes the single-tone tests, it is not a proof that it will happily pass complex tones, but when the unit fails on single tone test, it is enough proof that it does not perform well, which some of the examples in the article have clearly shown.MikoKensington said:But I also don't record music comprised of single high frequency tones. So that illustrated test doesn't "play" me anything.
abbey road d enfer said:[...]When a unit passes the single-tone tests, it is not a proof that it will happily pass complex tones[...]
In all practical terms, you are right. There is however, one very dubious theoretical case where it would not be completely true.jdbakker said:Not to harp on this too much, but:
abbey road d enfer said:[...]When a unit passes the single-tone tests, it is not a proof that it will happily pass complex tones[...]
I would argue that jitter is one of the few cases where a clean1 single tone test outcome guarantees that there are no jitter-related artifacts in complex signal playback/recording. At that point there may still be other problems (most notably intermodulation) that do only manifest with complex input waveforms. And of course, if the single tone reveals that there is jitter, one might still like the sonic impact.
JDB.
Good point. Although it's not uncommon for people to test the rejection of this by deliberately introducing jitter into an AES/EBU, S/PDIF or word clock input, I'm not aware of any standardised method.abbey road d enfer said:What about interface-induced jitter?
abbey road d enfer said:Oh, in fact, is that example really hypothetical? What about interface-induced jitter?
it's not the first time I hear about this happening, in particular with PT. I must say I find this very strange; how can one not recognize a sound playing a full tone too sharp and 10% above tempo?rascalseven said:a friend who uses my facility tracked and edited a lead vocal overdub at 48k (the AD's clock) when the session was actually a 44k1 session. He edited the vocal and burned a rough mix for listening back only then to realize the mistake when it hearing it back at 44k1.
abbey road d enfer said:it's not the first time I hear about this happening, in particular with PT. I must say I find this very strange; how can one not recognize a sound playing a full tone too sharp and 10% above tempo?rascalseven said:a friend who uses my facility tracked and edited a lead vocal overdub at 48k (the AD's clock) when the session was actually a 44k1 session. He edited the vocal and burned a rough mix for listening back only then to realize the mistake when it hearing it back at 44k1.
You mean you actually listened to the playback? ;DMartyMart said:abbey road d enfer said:it's not the first time I hear about this happening, in particular with PT. I must say I find this very strange; how can one not recognize a sound playing a full tone too sharp and 10% above tempo?rascalseven said:a friend who uses my facility tracked and edited a lead vocal overdub at 48k (the AD's clock) when the session was actually a 44k1 session. He edited the vocal and burned a rough mix for listening back only then to realize the mistake when it hearing it back at 44k1.
Ahem, I had to correct a set of masters from Mel-B's album ( Spice Girls ) that was all pitched up due to someone NOT
spotting this !!
It happens, they were a "pro" mastering house and I'm NOT !! ... go figure ...
MM.
abbey road d enfer said:it's not the first time I hear about this happening, in particular with PT. I must say I find this very strange; how can one not recognize a sound playing a full tone too sharp and 10% above tempo?rascalseven said:a friend who uses my facility tracked and edited a lead vocal overdub at 48k (the AD's clock) when the session was actually a 44k1 session. He edited the vocal and burned a rough mix for listening back only then to realize the mistake when it hearing it back at 44k1.
Enter your email address to join: