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VI Latency confusion: Vintage Warmer II
Posted: Wed Sep 19, 2007 7:10 am
by larryf
Hello, I'm wondering if anyone can shed light on, I guess, basic VI latency mathematics. I have a track I recently applied VWII to as an insert. Vintage Warmer says right on the screen graphic that it has 49.3 ms latency, which is huge, so I figured I should nudge the audio around to get it tight with the other tracks. I calculated the 49.3 ms in terms of # of ticks at the project's bpm, and moved the audio track up (i.e. toward the beginning, away from the end) that many ticks (I think it was ~ 40 ticks). It was then completely out of time with the rest of the project. I kept nudging it back 1-2 ticks at a time until it sounded "lined up". I ended up with it in exactly the same place it started. I either can't do math, or I don't understand latency, or something. Can anyone comment on how this works? Second question, if DP is somehow anticipating the VI and adjusting the latency, would it do the same thing if the effect was on an aux track as a send rather than an insert? Thank you
Larry
Posted: Wed Sep 19, 2007 8:43 am
by emulatorloo
AFAIK it is set and forget -- you do not need to do any "nudging."
I am sure there is more in the manual but I am away from mine, so just a couple links.
http://www.motu.com/products/software/d ... ation.html
http://www.motu.com/techsupport/technot ... tencyComp/
http://www.soundonsound.com/sos/feb05/a ... tudp45.htm
A key new feature in DP 4.5 is plug-in latency compensation, which feeds audio ahead of time into tracks which are carrying plug-ins that impose a processing delay. This works exactly as you'd want it to, ie. seamlessly throughout the mix environment, on every type of audio track. It's a superb implementation, and something that earns DP considerable kudos.
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http://www.motu.com/products/software/d ... 1813548304
Plug-in latency compensation means that I don't have to worry about which plug-ins I have on phase-crucial tracks (like room mics or drum overheads), and unlike some other DAWs, I can use them on aux busses.
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Posted: Wed Sep 19, 2007 8:48 am
by David Polich
VW II is reporting what the latency is, but DP is compensating for it.
There's nothing to be concerned about.
Posted: Wed Sep 19, 2007 8:53 am
by dweiss
Yes, DP has had automatic delay compensation for quite some time now. Don't nudge!
Posted: Wed Sep 19, 2007 9:09 am
by Tritonemusic
Okay, I think I'm losing my mind.
I just tested VW2 for a simple bounce from an audio track. No latency.
Then, I tested VW2 on an Auxiliary track. Latency.
This made me wonder...
I replaced VW2 with MW Limiter and bounced from an audio track. No latency.
Then, I tried MW Limiter on an Auxiliary track. Latency.
Isn't ADC supposed to work on Aux tracks? I hope somebody can clear this up for me.
I'm using the following:
••• DP 5.12
••• OS 10.4.10
••• G4 Dual 1.25 MDD
Posted: Wed Sep 19, 2007 10:14 am
by larryf
Thanks guys. I guess I wasn't connecting the dots that ADC would correct not just a milisecond or two, but even a plugin with 49 ms latency. I thought ADC was more of a micro-fine-tuning type of feature. This is good to know.
Okay, I think I'm losing my mind.
Your mind is in tact. I am experiencing the same problem, no ADC on the aux effects tracks. It's very hard to believe, but it's true, as far as I can tell.
Posted: Wed Sep 19, 2007 11:22 am
by emulatorloo
larryf wrote:I am experiencing the same problem, no ADC on the aux effects tracks. It's very hard to believe, but it's true, as far as I can tell.
Well it may have something to do with the Pre-Rendering feature in DP 5 which only works on insert plugs, not plugs on AUX tracks:
http://www.soundonsound.com/sos/jul06/a ... ?print=yes
What's New In Digital Performer 5
Digital Performer Notes
. . .pre-rendering.
Specific details on this new feature are tantalisingly scant, but it seems to work like this: when you place a plug-in on an audio track, dial in some settings and then close the plug-in's window, DP5 'pre-renders' audio in the track just ahead of the playback wiper, to sound exactly as though it was being treated in real time by the plug-in. The amount that is pre-rendered would seem to be equal to the Prime Seconds value, and is heard as soon as you start sequence playback.
What is absolutely not happening is any sort of automated Freeze of entire tracks ••” pre-rendering only works on a temporary basis and even then only for a couple of seconds worth of audio. But presumably, by whenever possible cueing up this short amount of audio, complete with plug-in effects, DP is able to reduce the processor usage associated with playback (and particularly with starting playback).
Pre-rendering is permanently 'on' in DP5, but the only time you might be made aware of its presence is if you hear a burst of dry audio as you open and close plug-in windows ••” apparently, an unavoidable side-effect. It only works on audio tracks, not Aux tracks or Instrument tracks, and even then not for mono-to-stereo, mono-to-surround or stereo-to-surround effects. If, for any reason, you don't want a plug-in to use it, you can check a new 'Always Run in Real time' option in the plug-in's mini-menu. There are apparently no implications for plug-in automation in either case.
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Posted: Wed Sep 19, 2007 11:40 am
by Tritonemusic
I don't think they should be related but I tried it, just in case, although I forgot to mention it. I tried bouncing with and without "Always Run In Real Time." It didn't affect anything in the bounce.
I'm almost positive that ADC used to work on Auxiliary tracks. Can anyone confirm this?
Posted: Wed Sep 19, 2007 11:53 am
by Spikey Horse
emulatorloo wrote:
Well it may have something to do with the Pre-Rendering feature in DP 5 which only works on insert plugs, not plugs on AUX tracks:
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Emulatorloo, can you clarify that a bit please - I'm confused now! .. I thought pre-rendering was just a CPU saver (doing calculations much earlier than it's needed on any plugs you're not about to tweak) whereas ADC is obviously shifting audio back in time to compensate for latency....
Did you mean the new(ish) PR feature now affects ADC behavior? Has ADC changed in its behavior at all? What
are its rules in DP at the moment?
I was sure aux tracks compensated .. in fact I emailed IKmultimedia again today to find out when T-Racks will get updated so it finally tells DP of its latency so I can start using it in parallel at last......
Aaaagh help!
Posted: Wed Sep 19, 2007 12:07 pm
by emulatorloo
Spikey Horse wrote:Did you mean the new(ish) PR feature now affects ADC behavior? Has ADC changed in its behavior at all? What are its rules in DP at the moment?
I was sure aux tracks compensated .. in fact I emailed IKmultimedia again today to find out when T-Racks will get updated so it finally tells DP of its latency so I can start using it in parallel at last......
Just guessing -- it seems to me that if PR did not work on AUX tracks, and all the other tracks were being PR'ed, then there might be some offset introduced on the AUX track because it is not being pre-rendered.
Again I am just guessing -- MOTU would be the ultimate authority.
Personally I have never noticed anything because I tend to limit myself to reverbs on AUX tracks so a little bit of slop would not be noticable to me.
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Posted: Wed Sep 19, 2007 12:17 pm
by Spikey Horse
...Hmmmm well I think it's time to test all this in a project! .....
Posted: Wed Sep 19, 2007 2:43 pm
by dogBoy
I have my Motif going in on an aux so I can keep the mix in the box.
If I put Vintagewarmer across a Master Fader the Latency is real apparent.
So, I don't use it if I'm running outboard MIDI.
I've used VM as an AudioSuite to do a hardcopy and it put blankspace up in front of the soundfile.
Good stuff to be aware of.
Posted: Wed Sep 19, 2007 2:46 pm
by swiftness
Don't know if it was a typo but the title of this thread implies that you're using a virtual instrument as the source for your aux track... ADC does not work on Aux tracks when the input is a virtual instrument. It does work on Aux tracks when the input is an audio track. Hope that helps.
Posted: Wed Sep 19, 2007 3:17 pm
by swiftness
666 - I do not receive latency on my aux tracks when the source is an audio file and not a VI or live instrument.
...you deleted your last post to me, but I just did a quick test to confirm, so I wanted to let you know.
Posted: Wed Sep 19, 2007 3:52 pm
by Tritonemusic
Swiftness,
I wanted to double-check my tests, that's why I deleted it. I tried bouncing with MW EQ and the bounce was sample-accurate, even on the Aux track. However, when I tried MW Limiter with "Lookahead" set to maximum, ADC does not work. If you find the time, could you try a test using MW Limiter with Lookahead set to 20.00 ms. on an Aux track? I don't think it should make a difference but, for the record, my Buffer setting is set to 1024.
Edited to add:
I bounced with MW Limiter with "Lookahead" set to 0.00 ms. The bounce was sample-accurate.
I bounced with MW Limiter with "Lookahead" set to 20.00 ms. The bounce was late.