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Old 5th April 2008 | Show parent
  #22
Here for the gear
 
There's some misinformation going on here. To clarify some things, let's first identify the two types of delay compensation that takes place in PT-HD.

First, there's the compensation that takes place after a recording pass that advances the newly recorded track by the input and output delays to line it up exactly with what's already recorded in Pro Tools. The control over this compensation is on both the input and output tabs of the I/O setup window. With the boxes checked, PT will compensate for the input and output delays based on the hardware setup configuration for that particular input or output channel. PT knows the proper value for Digidesign interfaces only. Second, there's ADC which we all know works to compensate for delays incurred by plug-ins and hardware inserts during mixing. The hardware inserts are compensated by the ADC engine by the same mechanism that the record-pass compensation occurs, that is, PT knows the correct compensation value for all Digidesign interfaces based on the hardware setup configuration.

Though I have not used a Lynx Aurora, I am told that it has I/O delay times identical to a 192, regardless of whether the connection is analog or digital. What I have used extensively is the 192, a Rosetta 800 and a couple of DA-16Xs. Even though the Apogee interfaces show up as 192 Digitals in the hardware setup with the firmware update, they still do not match any of the Digidesign interfaces in terms of I/O delay. This means that tracks recorded through an Apogee interface will not line up exactly where they should even if you've selected to compensate after a record pass. Also, if you like to mix OTB, then if you span outputs across multiple non-identical interfaces, they will not be properly together in time. There's even a difference in time between the output of the Rosetta and a DA-16X. The really weird thing is that the difference between them isn't even a whole sample value.

The difference in conversion delay times is not much more than 1.5 milliseconds. Practically speaking, this isn't a big deal unless you're obsessive/compulsive about the precision that you believe you should have in a professional recording system. On the other hand, this difference is big enough that drum tracks cannot span multiple outputs on non-identical interfaces when mixing OTB. While being able to manually enter the additional ADC compensation values for hardware inserts in the I/O setup window is helpful, it does absolutely nothing for compensating properly for I/O delays during a record pass, nor for lining up analog outputs on multiple interfaces. If you're mixing OTB, the only thing you can do is manually enter additional ADC values for the different Apogee interfaces directly into the ADC window at the bottom of each track in the mixer window.

So who should be responsible for fixing this issue? Should Digidesign allow PT to recognize and compensate properly for third party interfaces, or should Apogee re-engineer their products to have identical delays to a Digidesign interface?