Login / Register
 
ProTools HD - Hardware I/O latency
New Reply
Subscribe
3dchris
Thread Starter
#1
13th March 2008
Old 13th March 2008
  #1
Gear nut
 
Joined: Dec 2007
Location: Toronto, Ontario, Canada
Posts: 75

Thread Starter
Send a message via MSN to 3dchris
3dchris is offline
ProTools HD - Hardware I/O latency

I'm fairly new to pro tools hd and I have a question. I have bunch of outboard gear that I'm trying to use as inserts or as a send returning to aux channel. The question is: what about the latency of harware compressors/ eqs etc? Even with delay compensation enabled I still hear some latency. There is a way to enter latency compensation values in I/O setup window but how do you calculate that value? I'm using a lot of parallel compression using external gear and this bothers me a bit.

Thx,

Chris
#2
13th March 2008
Old 13th March 2008
  #2
Lives for gear
 
Zep Dude's Avatar
 
Joined: Jul 2002
Location: Brooklyn, NY
Posts: 1,173

Zep Dude is offline
If you do a send returning to a different aux channel PT latency compensation won't work. You have to do this as an insert. If you have 192 interface the hardware latency comp is already set up, otherwise you can manually enter values either per track or in the IO window per channel. To figure out your DA-AD latency play a track through the DA-AD loop and record it back. compare the waveform of the new track to the original and that will tell you the latency delay. However, with some converters, like apogee they have less latency than the 192's so you have to enter the offset value for each individual track -see their website. You should read the manual on this. It's important to understand how this all works to keep your tracks in correct phase with each other. "Automatic" Delay Comp is not really so automatic.

Also, some plugins, like the MDW don't report correct values to delay comp -its off by 1 sample so you'll hear phase issues with parallel tracks. I've heard some of the Waves have this issue as well.

Any latency your analog gear has is only measurable in the nanoseconds -way less than 1 sample.
__________________
Angelo Montrone

Majestic Music Factory: Studio / Label
Majestic Music Mastering
Twitter: @MajesticMusicNY
3dchris
Thread Starter
#3
13th March 2008
Old 13th March 2008
  #3
Gear nut
 
Joined: Dec 2007
Location: Toronto, Ontario, Canada
Posts: 75

Thread Starter
Send a message via MSN to 3dchris
3dchris is offline
Quote:
Originally Posted by Zep Dude View Post
If you do a send returning to a different aux channel PT latency compensation won't work. You have to do this as an insert. If you have 192 interface the hardware latency comp is already set up, otherwise you can manually enter values either per track or in the IO window per channel. To figure out your DA-AD latency play a track through the DA-AD loop and record it back. compare the waveform of the new track to the original and that will tell you the latency delay. However, with some converters, like apogee they have less latency than the 192's so you have to enter the offset value for each individual track -see their website. You should read the manual on this. It's important to understand how this all works to keep your tracks in correct phase with each other. "Automatic" Delay Comp is not really so automatic.

Also, some plugins, like the MDW don't report correct values to delay comp -its off by 1 sample so you'll hear phase issues with parallel tracks. I've heard some of the Waves have this issue as well.

Any latency your analog gear has is only measurable in the nanoseconds -way less than 1 sample.
Zep Dude! Thank you so much for this quick answer. I'm using SSL Alpha Link / Delta Link converters so I have to do the recording test to figure out the latency. You say that if I return to separate aux channel then the digi delay compensation won't work, right? But since there is virtually no latency on the hardware side then the only latency is on the converter side, right? So if I enter proper latency values in all I/O fields (should be the same number for all 24 I/0 , right?) then it should not matter to which channel I return the signal. Are those manually entered values part of automatic delay compensation or not? According to logic they should not be. Am I right?

chris
#4
13th March 2008
Old 13th March 2008
  #4
Lives for gear
 
dubrichie's Avatar
 
Joined: Nov 2005
Location: Dublin, Ireland
Posts: 2,500

dubrichie is offline
well, since the SSL Alpha Link / Delta Link have to go through TWO boxes before they reach the ADDA and the correlating i/o channels are not recognised by PT, yes, you will have to adjust the latency manually.

easiest way is to send a transient audio "ping" signal through the i/o (DA/AD) that you want to insert/send/return on and then use this "spike" in the waveform to visually calculate the exact delay in samples, having zoomed in on the waveforms.
__________________
Regards,

Richie.

"a paradigm of restraint and good taste at a time of frequent excess"
3dchris
Thread Starter
#5
13th March 2008
Old 13th March 2008
  #5
Gear nut
 
Joined: Dec 2007
Location: Toronto, Ontario, Canada
Posts: 75

Thread Starter
Send a message via MSN to 3dchris
3dchris is offline
Thanks Richie! Will it work OK in the "send-aux" scenario as well? I hope I don't have to manually check all the files all the time!

thx,

chris
#6
14th March 2008
Old 14th March 2008
  #6
Lives for gear
 
dubrichie's Avatar
 
Joined: Nov 2005
Location: Dublin, Ireland
Posts: 2,500

dubrichie is offline
yes, it should.

once you specify the i/o path (ie which output and which input to be used for the send and aux respectively) this method should work just fine and you should only have to do it once.

however, i may be wrong and am willing and able for a healthy correction!
#7
14th March 2008
Old 14th March 2008
  #7
Lives for gear
 
lozion's Avatar
 
Joined: May 2005
Location: Changes all the time..
Posts: 1,896

Send a message via Skype™ to lozion
lozion is offline
not to hi-jack or anything but what about converters going in lightpipe to the 192/96?
Are they automatically compensated for in the same manner as the ad/da of the digi boxes? And to push the question further, what about converters going in lightpipe thru an adat bridge via the legacy port? Mmm
__________________
"The secret in life is to have no fear"
Fela Anikulapo Kuti
#8
14th March 2008
Old 14th March 2008
  #8
Lives for gear
 
dubrichie's Avatar
 
Joined: Nov 2005
Location: Dublin, Ireland
Posts: 2,500

dubrichie is offline
Quote:
Originally Posted by lozion View Post
not to hi-jack or anything but what about converters going in lightpipe to the 192/96?
Are they automatically compensated for in the same manner as the ad/da of the digi boxes? And to push the question further, what about converters going in lightpipe thru an adat bridge via the legacy port? Mmm
i don't think so, as PT has no way of "knowing" what the latency of the other converters connected via lightpipe is.

again, you will have to "ping" them and manually enter the values in samples.
#9
14th March 2008
Old 14th March 2008
  #9
Lives for gear
 
lozion's Avatar
 
Joined: May 2005
Location: Changes all the time..
Posts: 1,896

Send a message via Skype™ to lozion
lozion is offline
Quote:
Originally Posted by dubrichie View Post
i don't think so, as PT has no way of "knowing" what the latency of the other converters connected via lightpipe is.

again, you will have to "ping" them and manually enter the values in samples.

Well, stangely enough, there is compensation happenning on those lightpipe channels, suggesting PT does ping itself to apply proper correction... Maybe because those i/o's ARE running through a DIGI box, as opposed to 3rd party interfaces where manual compensation needs to be applied?
#10
16th March 2008
Old 16th March 2008
  #10
Lives for gear
 
lozion's Avatar
 
Joined: May 2005
Location: Changes all the time..
Posts: 1,896

Send a message via Skype™ to lozion
lozion is offline
mmm?
New Reply Submit Thread to Facebook Facebook  Submit Thread to Twitter Twitter  Submit Thread to LinkedIn LinkedIn  Submit Thread to Google+ Google+ 
 
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Similar Threads
Thread
Thread Starter / Forum
Replies
tonyscarbones / Rap + Hip Hop engineering & production
8
s0nguy / Music Computers
5
Stoneroses6300 / Music Computers
3

Forum Jump

SEO by vBSEO ©2011, Crawlability, Inc.