ATTN: Abes: Overall Latency setting

MrYellow · Post by **MrYellow** » Wed Apr 20, 2005 1:55 pm

How does it work?

What does it do?

We need clarification here.....

To my thinking, adding latency to Live would be for syncing it to slower
sources such as another computer. Thus, if another computer has a crap
card and is running 30ms behind yours you can add 30ms to your latency
to slow yours down to be back in sync.

Now you could say this could be used with a slower "device" like a guitar....
By delaying the Live playback..... However if this delays the live playback
then you're just playing along with something delayed and still out of sync.

However.... some say with monitoring turned off it allows you to ADC/PDC
and bring stuff back into sync. For the life of me this doesn't make sense,
how can 1 + 1 + 1 = 0?

Also if this is in-fact how this works..... Why have we had 50 threads
requesting it as a feature???

Does it delay Live's playback by adding additional latency?

Does it remove x ms of samples from the start of a clip when recording stops?

-Ben

montrealbreaks · Post by **montrealbreaks** » Wed Apr 20, 2005 2:51 pm

MrYellow wrote:How does it work?

What does it do?

We need clarification here.....

To my thinking, adding latency to Live would be for syncing it to slower
sources such as another computer. Thus, if another computer has a crap
card and is running 30ms behind yours you can add 30ms to your latency
to slow yours down to be back in sync.

Now you could say this could be used with a slower "device" like a guitar....
By delaying the Live playback..... However if this delays the live playback
then you're just playing along with something delayed and still out of sync.

However.... some say with monitoring turned off it allows you to ADC/PDC
and bring stuff back into sync. For the life of me this doesn't make sense,
how can 1 + 1 + 1 = 0?

Also if this is in-fact how this works..... Why have we had 50 threads
requesting it as a feature???

Does it delay Live's playback by adding additional latency?

Does it remove x ms of samples from the start of a clip when recording stops?

-Ben

Well, the reason I have requested delay plug compensation is if I put a heavy delayed VST effect (PSP vintage Warmer for instance) on a CHANNEL rather than on the master outs, then THAT CHANNEL is delayed by around 15 milliseconds - but none others are.

Adjusting the delay in the preferences as you point out, would add that time to the master output (and possibly the other outputs but I am not certain). This would not solve the problem in that everything on the vintage warmer channel is STILL delayed relative to the rest of the material.

What we have been asking for is something that automatically detects the delay of your slowest plugin, and then delays everything else so that they are back in sync.

for instance:

Channel 1: VST compressor with look ahead, 15 millisecond delay
Channel 2: VST Instrument, 4 millisecond delay
Channel 3: no effects, no delay
Master channel: VST limiter with look ahead, 1 millisecond delay.

What probably happens in Logic and Cubase is that the 15 milliseconds of the Channel 1 is recorded as the longest delay. This is calculated by sending an inaudible pulse of data (a test signal) through all routings and timing the difference.

Then, they will delay channel 2 by 11 mililseconds, and delay channel 3 by 15 milliseconds so that everything is in sync again. If I were to add a second hardware output (not on the master bus) it would add 1 millisecond delay to that other output, to match the limiter on the master.

It's a pretty spiffy feature, actually.

The delay you see on the preferences page is useful still though. Consider if you have a MIDI tone generator sequenced by the computer, or even just synced to the computer; but it's consistently 20 milliseconds behind your computer's audio... This is common, especially considering that MIDI is an old protocol. Now you'll want to delay your computer's audio to match the MIDI signal being sent. This will delay EVERYTHING by what you type in - useful for external gear, but useless for different delays caused by different plugs in the software.

Hope that helps - I am no guru on this, but this is my best 'estimation' of what happens with delay compensation.

mjpetersen68 · Post by **mjpetersen68** » Wed Apr 20, 2005 3:20 pm

montreal, you've hit the nail on the head with your Plug-in delay compensation summary. it's about DELAYING the playback of tracks by varying degrees.

However, the overall latency adjustment in Live! does NOT delay the playback of tracks, it simply shifts a recorded track to an earlier point in the timeline AFTER the recording has taken place, i.e after you hit "stop".

this seems to be the point that most people are stumbling on, confusing the REAL TIME effect of PDC with the concept of Overall Latency Correction, where live is simply MOVING a track in the timeline AFTER the recording has stopped. This is key to understanding what's going on. The samples are'nt being "trimmed" off the front, coz there ARE no samples at the front, the sound from your input hasn't GOT there yet.

This could be why some people are saying "Overall Latency Doesn't work", if they're expecting to put in a figure in the box and expect an extra delay. It doesn't work like that.

Like everyone, I'm keen to hear Ableton's official response, but look, if you're really keen, just get a patch lead, run your in's to your outs, set the Overall Latency Correction to a VERY high amount (so you can see clearly what's going on) and just play around. You'll have it sussed in no time.

Matt

feyshay · Post by **feyshay** » Wed Apr 20, 2005 6:08 pm

Wow! Three latency posts within a short-time. Surprise! Surprise! I'm still trying to get a grip on things. I'll post what I just posted on another post here. Montrealbreaks--how did you determine 15ms for Vintage Warmer. Obviously, that will be computer dependent, no? Or is there a certain lookahead amount that is published in the VW manual? I find that other plug-ins that can give me some latency include Firium (has a look-ahead), Voxengo's Soniformer, and some other PSP (Maxpressor, saturator). It can get quite tedious to try to micromanage to get everything in synch. Yet, I don't want to limit their use to just the Master.

Posted before:

If you can't get the whole Monitor Auto/On/Off latency adjustment biz figured out, a relatively easy fix is to use a plug-in to delay the track that seems to be ahead. (This would be the track that you first recorded.)
Go to voxengo.com and download their Latency Sample delay (free). Then plug-in the amount of samples that are buffered on your MobilePre.
You'll see typical presets like 256, 512, etc. Usually one of those.
What gets more complicated is when you are recording a second track and have plug-ins on your first track that have some delay (e.g some compressors, analyzers, reverbs). Then you may have to do some experimenting to get them in synch by dialing the sample delay. Live does not have a built-in latency compensation for plug-ins.

MrYellow · Post by **MrYellow** » Thu Apr 21, 2005 1:06 am

how did you determine 15ms for Vintage Warmer.

They are kind enough to print it at the bottom of the interface...
For me it was 11.2ms....

Ok...... so that's 1 for "It delays the whole mix x ms" and 1 for "It starts recording x ms late to compensate".

Now that I've worded it that way..... "delays the start of recording" I can see
how 1+1+1=3 isn't a bad thing. However.......... If we have so many
confused users, think an official explaination other than the manual is
really needed. At least that way us forum users can pass on the correct
information knowing it's 100% correct.

-Ben

MrYellow · Post by **MrYellow** » Thu Apr 21, 2005 12:56 pm

bump

emailing them a heads up....
see if we can get this cleared up once and forall.

-Ben

kleine · Post by **kleine** » Thu Apr 21, 2005 1:23 pm

Hello Mr. Yellow,

The Overall Latency setting is only relevant when recording audio with monitoring set to “Off” (see Monitoring). This would be the case if you were, for example, recording an acoustic instrument and “monitoring” through the air.
Live compensates for these latencies by moving the recorded samples ahead in song time.To do this, it needs to have precise information about the actual input and output latencies in the system. The latency value reported to the software by the audio hardware drivers is not always completely accurate, however. The Overall Latency setting is a way to tell Live about any deviations from the reported values.
Live does not have trackwise/plugin delay compensation yet.

I hope this helps.

Best,
Christian Kleine
[email protected]

waldo · Post by **waldo** » Thu Apr 21, 2005 1:39 pm

Live does not have trackwise/plugin delay compensation yet.

god how i love that little word on the end of that sentence : yet.

because this probably means they are busy with it.

tee hee

montrealbreaks · Post by **montrealbreaks** » Thu Apr 21, 2005 9:00 pm

MrYellow wrote:
how did you determine 15ms for Vintage Warmer.
They are kind enough to print it at the bottom of the interface...
For me it was 11.2ms....

-Ben

That's nuts! I never even looked there... I actually rendered a pulse of audio through it and looked in a .wav editor to see the delay of the Vintage Warmer...

I guess there's always an easy way and a hard way to do something, and I did it the hard way. go figure.

MrYellow · Post by **MrYellow** » Fri Apr 22, 2005 5:11 am

Live compensates for these latencies by moving the recorded samples ahead in song time.

I've been over that a hundred times in my head......
I'm still not really certain what it means....

Sounds like it fixes latency..... but I'm a "how" kinda guy......

Guess it's #2.... starts recording x ms after it would normally.

So now....

I need to buy a new external mixer with more channels and features. Then
route everything out to the mixer and use that instead of Lives mixer....
However then I miss the master bus which is where I like to put some
effects.

Or

I need to copy clips into a track which is set to send to my monitor
outputs then copy it back into the track for Live output..... Or change it's
outputs to switch it from monitor to FOH.

Otherwise I won't be able to monitor clips b4 sending FOH....

It's just so good to have on a button like it is with "monitor thru live".

-Ben

mjpetersen68 · Post by **mjpetersen68** » Fri Apr 22, 2005 8:14 am

ben, that's not exactly it.

Live didn't start recording later, it started recording as soon as you hit record. So the START of the actual samples are in sync, just not the sound IN them. This is because, in those first few milliseconds of recording, your vox input was still making it's way down the wire to your computer.

so your vox finally makes it to the track, and you see the waveform in the track viewer appear as you sing. BUT because there was that "dead time" when your voice was still travelling down the wire, the first few milliseconds of your recorded vox is SILENCE. Live was recording, but the input that was being recorded hadn't got there yet.

When you play back the two tracks together, your vox sounds late.

So, to create a WORK AROUND for this problem, live asks you to stick in the number of milliseconds that your input is constantly late to the track (which you worked out using the patch cable method). Then, every time you record a sample, when you hit STOP, Live! says "oh, he's just recorded something, I know that sample is going to sound late to him because of latency, so I'll just grab the sample and move it to the left by the X milliseconds that he told me before". And voila, the two tracks sound in sync again. Now, if there is no more "left" (because you started recording at the absolute beginning of the track) those few milliseconds of silence simply get trimmed and binned.

If there's interest from the group, I'll write a better explanation of latency management in Live! and post it in the Tips section.

MP

MrYellow · Post by **MrYellow** » Fri Apr 22, 2005 8:49 am

"oh, he's just recorded something, I know that sample is going to sound
late to him because of latency, so I'll just grab the sample and move it to
the left by the X milliseconds that he told me before".

That's the way we think about it..... but not the way it actually works.....
Which is why 1 + 1 + 1 = 0 is confusing....

How it actually seems to work tho.... is.... Live starts recording x ms later
then it would have, thus there is no silence, and the sample doesn't need
moving to the left, as Live was not recording when the silence was coming
down the wire. This makes 1 + 1 + 1 = 3 make sense.... It's not about
creating 0 latency, it's about delaying the onset of recording.

So this setting only delays when live starts recording, it doesn't delay the
whole mix as it would appear. So it's not a method for syncing with external
gear, but for effectively overcoming the problem of silence at the start of a
recorded clip.

So that 5 page thread asking for ADC as a feature was a waste of time....
As this does the trick. Wish it was more clearly defined....

Anyway....... HEY HEY HEY........

I just discovered that PFL still works with "Monitor thru Live" switched off.....
I always thought u needed it on to PFL.... So "Monitor thru Live" is a fairly
useless feature and you can actually do everything needed with it switched
off (except monitor live instruments with their effects on, only the raw input
can be monitored)....... awesome.

-Ben

ConneKted · Post by **ConneKted** » Fri Apr 22, 2005 8:58 am

This is what i do to solve this ...when a recorded track/clip is delayed in time due to latency, i just move my first warp marker to the right. The wunderfull time stretching feature corrects everything (audible that is).

or is it that my hearing turns bad .... ?

mjpetersen68 · Post by **mjpetersen68** » Fri Apr 22, 2005 9:02 am

ben, i see your point now, but I guess whether the recording start is delayed (as you say) or trimmed and shifted (as I suggest, based on Abelton's own response) has the same effect at the end of the day.

as I said, I don't know where the "1 + 1 + 1 = 0" statement came from, and I don't really see the confusion. Live says "i reckon total latency is 5+6=11" and the user gets out his patch cable and says "no, you've missed by a bit, it's actually 15. so I'll stick in another 4 to make up the numbers". hence, 5+6+4=15. Not sure how zero could ever come into it.

sorry, I'm with the Abes on this one. It makes sense. Where it fails (if at all) is being "different" from the way other DAWS state/workaround latency.

MP

mjpetersen68 · Post by **mjpetersen68** » Fri Apr 22, 2005 9:05 am

but if you use warp, won't your sample be changed in length, i.e it'll be in sync at the start but out of sync at the end.

do you mean the start marker?

ATTN: Abes: Overall Latency setting

ATTN: Abes: Overall Latency setting

Re: ATTN: Abes: Overall Latency setting

latency delay--audio device and plug-in