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another PT PDC question...
Old 17th November 2009
  #1
Lives for gear
 

another PT PDC question...

I know there are 10s of PDC related threads here, but I don't wanna complain about it. I have a legit question...

I was browsing on "Colin's corner" at McDSP.com and stumbled on the following:

Quote:
Most McDSP plug-ins have the lowest latency allowed in a Pro Tools TDM plug-in – 3 samples. RTAS plug-in algorithms have ZERO latency, but the audio is still delayed by the selected hardware buffer size in the Pro Tools system. The only exceptions are the ML4000 and Revolver plug-ins. The ML4000 has 55 samples of delay at 44.1 kHz sample rate due to its look-ahead system (although this is the smallest look-head system, by 1,000’s of samples in some cases, of other limiters on the Pro Tools platform). The Revolver convolution reverb has a latency of 1024 samples (although if the Pro Tools buffer size is 1024 or greater, and Revolver is in Low Latency mode, the effective latency of the Revolver plug-in becomes zero samples, as the playback buffer size is equivalent to the buffering inside of Revolver).
It were those last sentences that attracted my attention. As I understand it, the PDC readout below the fader in PT is meant to help you when manually aligning the tracks. Either by nudging them or putting delay compensators on the other tracks. These last sentences however imply that you don't have to as long as the readout is below, or exactly the used buffer size.

When you change buffer sizes in PT the latency readouts don't change. When, at 128, a channel reads 24 samples of delay, it doesn't change to 0 when you change the buffer to 256. So the readout is the total delay. Not the delay relative to the buffer size.

Please enlighten me... Is this a unfortunate typo or am I missing something here... Surely it must be the 1st, cause people are nudging audio based on the delay readout. If what Colin writes is true they would actually be un-alligning their tracks...
Old 25th November 2009
  #2
Gear Head
 

No sure to understand clearly your question, due to my bad english, but what I know, as a long time Pro Tools LE user, is that Pro tools LE doesn't have ADC, Automatic Delay Compensation. So, your Revolver reverb is always coming 'too late', specially with big buffer size when...mixing.

I discover that few month ago, with a very hungry plug called Vintage Warmer 2 (2051 samples of delay) and the group of drums I treated becomes completly out of time ! Put the plug out and every thing is back in time. This is the same thing when apply a Wave or what ever plug(s) on top snare track for instance: your bottom snare track is now out of phase, so you must put the same plug(s) on bottoms snare ,even on by pass, just to keep things together....

THIS is why I left Pro Tools LE down, and turn to Ableton Live wich really have an ADC wich works perfectly. This is why I plan to sell my McDSP plugs, because they don't work in VST format. This why I wrotte yestreday to McDSP to know how to transert my licenses.

And great news for me, they plan for 2010 to get AU versions of their plugs ! coooool !


hope it helps, but do a test, there is now ADC in pro tools LE. Digi keeps this for HD user....

JB

(North of the France, not so far from Holland !)
Old 25th November 2009
  #3
Lives for gear
 

Quote:
Originally Posted by jbsteho View Post
No sure to understand clearly your question, due to my bad english, but what I know, as a long time Pro Tools LE user, is that Pro tools LE doesn't have ADC, Automatic Delay Compensation. So, your Revolver reverb is always coming 'too late', specially with big buffer size when...mixing.

I discover that few month ago, with a very hungry plug called Vintage Warmer 2 (2051 samples of delay) and the group of drums I treated becomes completly out of time ! Put the plug out and every thing is back in time. This is the same thing when apply a Wave or what ever plug(s) on top snare track for instance: your bottom snare track is now out of phase, so you must put the same plug(s) on bottoms snare ,even on by pass, just to keep things together....

THIS is why I left Pro Tools LE down, and turn to Ableton Live wich really have an ADC wich works perfectly. This is why I plan to sell my McDSP plugs, because they don't work in VST format. This why I wrotte yestreday to McDSP to know how to transert my licenses.

And great news for me, they plan for 2010 to get AU versions of their plugs ! coooool !


hope it helps, but do a test, there is now ADC in pro tools LE. Digi keeps this for HD user....

JB

(North of the France, not so far from Holland !)
Thanks.

I am aware of the lack of PDC in PT LE. The reason I asked was because of the contradiction between PT not having PDC and Colins text...

I read it again, and he basicly says: If a plugin has 1024 samples of latency and your buffer is at 1024 you don't have to allign/nudge anything... With all my knowledge of PDC that simply cannot be true. PT doesn't compensate the delay and the track should be nudged 1024 samples...

Again, is it a typo, or am I missing something...
Old 25th November 2009
  #4
Gear Addict
 

I think I've read that this is the case when using plugs during recording, but I've never seen anything in any Digi documentation that confirms this. So I feel that it's something that someone has misunderstood at some point that has spread.
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