Latency/Delay Compensation Confusion

Nuendo
#1

I’m a bit confused about latency and delay compensation:

  1. It is my understanding that plugin delay is automatically compensated for if ‘Constrain Delay Compensation’ is not active, so can we ignore the info displayed in the Channel Latency section on the MixConsole? Does this have any practical use or is it displayed just for information only?

  2. If I select an FX channel on the Project screen, select the ‘Insert’ entry (in this case an external PCM-91) and then click on the ‘Measure Effects Loop Delay’ icon, the loop’s delay is obtained and placed on the ‘Delay______’ line - in this case ‘6.73 ms’. Is this in effect a negative number that will pull up the returning signal to keep it in sync with the original, dry signal?

I’m hard pressed to hear any difference between a setting of 0.00 and 6.73 ms; any difference I am hearing may well be imaginary!

Why is this delay not automatically compensated for?

There is of course a good chance that I might be misinterpreting everything.

#2

Here is a pic of what I am talking about in 2. above:

IMG_3139.JPG
IMG_3139.JPG3184×1812 1.51 MB

#3

If constrain is Off the DAW will automatically do delay compensation for Inserts along the project.
For external gear based on time fx , like the PCM 91 its always good practice to ping the machine in its dry state . otherwise it will do calculations based on the time differences with the FXs on.
Not a Nuendo user, so maybe some people have way more experience in this topic .
All the best

#4

You are right, it’s informative but the practical use for me at the studio where everything is tracked/monitored thru Nuendo is knowing exactly what latency perfomers are getting in their headphones (besides ASIO buffer and AD/DA converters) as soon as i insert a plugin on a track.
Before that feature was introduced, I went through the hassle of having to ping every plugin on my system for latency value, and write it down !

No, all your audio on all your tracks will be delayed by 6.73ms to be in sync with your external fx.

When you ping external FX, be sure to set the mix of the effect to “dry”, you shouldn’t have a value of 6.73ms unless you go through a whole lot of AD/DA converters on the way to the PCM91 and back…and if it is connected by Digital (AES, Spdif, Adat…) you should get near zéro latency.

in your case of a reverb, if you manually set the value to 0.00ms and your reverb mix setting is set to “Wet”, you’ll just have a 6.73 predelay on your reverb that you’ll have to add to the predelay setting of your PCM reverb…

From what I recall, whenever you insert an “external FX” which has been “pinged”, it’s latency is automatically compensated for.

Hope this helps

Regards
Yannick

#5

Yannick, thanks for your very detailed and informative reply.

  1. QUOTE “You are right, it’s informative but the practical use for me at the studio where everything is tracked/monitored thru Nuendo is knowing exactly what latency perfomers are getting in their headphones (besides ASIO buffer and AD/DA converters) as soon as i insert a plugin on a track.
    Before that feature was introduced, I went through the hassle of having to ping every plugin on my system for latency value, and write it down !”

What do you actually do with the latency figures?

In my case, all recording is monitored directly thru the RME FireFace UFX interface not Nuendo so perhaps it is irrelevant to me.

How does one ‘ping’ things?!

  1. QUOTE “When you ping external FX, be sure to set the mix of the effect to “dry”, you shouldn’t have a value of 6.73ms unless you go through a whole lot of AD/DA converters on the way to the PCM91 and back…and if it is connected by Digital (AES, Spdif, Adat…) you should get near zéro latency.”

If I set the PCM-91 to dry (0% Wet) and click on the little Top Hat icon it shows a latency of 1.16ms.

The connections to the PCM-91 are AES input from the RME then output back to the RME via normal audio outputs.

QUOTE “In your case of a reverb, if you manually set the value to 0.00ms and your reverb mix setting is set to “Wet”, you’ll just have a 6.73 predelay on your reverb that you’ll have to add to the predelay setting of your PCM reverb…”

I’m not quite clear on this. Won’t that give me a a predelay of 13.46 ms.

Sorry to sound like such a twerp.

#6

Latency figures lets me choose plugins with no latency or low latency if I need (some plugs even have different latencies if you switch some options on/off for example “Linear Phase” mode one some plugins introduce much more latency…so I see exactly what is going on latency wise on the mixconsole.

In your case, it is irrelevant as you use Totalmix with near-zéro latency for monitoring.

I use RTL Utility from Oblique Audio to “ping” stuff :
https://oblique-audio.com/rtl-utility.php


That 1.16ms is much more realistic as you have near zéro latency via AES and then you just have the latency of your RME A/D conversion on the way back from your PCM to your Nuendo

And that value is the round-trip latency, it pings the time it takes for the sound to leave nuendo, go to your PCM and back in to nuendo.
So no, in the example of the 6,73ms delay you had measured, if you defeat it and set the value to 0.00ms, it would have given you an “invisible” 6.73ms predelay on your PCM…

Regards
Yannick

#7

Yes, that is correct. It measures the latency of the AD/DA chain that your outboard (and maybe the latency your hardware introduces) “consumes”.

Fredo

#8

I thought that would be the case, but do I need to do anything about it, or will Nuendo just take care of it?


I tried it today with the 1.16ms and it sounded fine.

#9

After pinging, the latency is automatically compensated for.
Ping and forget.

Fredo

#10

…as far as i see, latency is only compensated on playback. monitoring through nuendo during recording and while using inserts of any kind generating different latency-values will exhibit the usual problems.

#11

Hi Fredo,

If I’m right you do have to ping your External FX again if you change sample rate no ?

Hence the multiple user requests for saving/loading the entire External FX page in the Studio Connections tab as presets with all it’s naming, routing and latency no ?

Regards
Yannick

#12

Depends on the external hardware. Digital? Analog?

That being said, since reverbs always have some kind of pre-delay, it doesn’t matter at all.
It does matter when you are using external EQ or compressors.
That being said, a lot of analog compressors have a variable latency; but that is no different to the old analog days.
etc …


Fredo

#13

OK, still confused.

I’m mainly concerned about mixing and I don’t use external EQ or compressors.

After pinging any external effects will everything remain in sync (latency wise) while mixing?

#14

Yes.

Fredo

#15

PDC really wants a tutorial doesnt it?

Not for myself it’s just that PDC, as a concept, seems confusing to many.

For instance, back in the day when it was first being implemented, Steinberg made a choice that the On-Off switch is backwards from what many people would expect. That is, selecting that button disables rather than enables PDC because its natural state is On. Makes total sense if you understand what PDC is doing under the hood but if you don’t I think it is counterintuitive.

Is there a really good Steinberg specific tutorial to point people to? There could be one in the manual I don’t know because I don’t need it. Just seems like it would be helpful after looking at this thread.