Hi all
Maybe wrong forum, anyway. I, as most of us I believe, have problems witH latency when recording overdubbing. Some of you have audio interfaces with "zero latency" features ( presonus & focusrite, and maybe others). My question is, how well does the said interfaces manage this problem? I'm asking because I have recently learned that you could have a setup including a mixer, in order to obtain a thrue zero latency setup. What are your thoughts about this?
If one of you would explain the minimum features for the mixer in order to obtain ZL I would very much appreciate it.
Thanks

Jan

Great question.
 
Near zero latency can be achieved if you keep the monitor mix on the analog side of the analog to digital conversions.
 
If you use the dsp mixer on one of the common "zero latency" I/O boxes your minimum round trip latency will actually be about 2 milliseconds. The companies that describe that as "zero" latency are simply lying about the specs and they plan on nobody caring about either the 2ms or the misleading statements.
 
Some drivers allow small enough sample buffers that the throughput to and from the DAW is inconsequential and so 2ms is also the practical minimum you can expect for anything making a analog-digital-analog round trip.
 
As a comparison, if you are looking at the timing for a round trip through an analog monitor mix you can consider it would take an approximately 700 kilometer long audio cable to experience a 2 millisecond delay in the analog domain.
 
Even though analog would accurately described as near-zero latency you can see that it is closer to zero than the "zero latency" digital solutions by orders of magnitude.
 
 

mike_mccue
If you use the dsp mixer on one of the common "zero latency" I/O boxes your minimum round trip latency will actually be about 2 milliseconds. The companies that describe that as "zero" latency are simply lying about the specs and they plan on nobody caring about either the 2ms or the misleading statements.

This point is key. If the zero latency option comes through analog means, i.e., the input signal is picked up from an analog mixer and sent to an analog output, only then do you have true zero latency. 
 
With DSP there is latency caused simply by going through A/D and D/A conversion which I believe is the issue to which Mike refers. The latency varies with sample rate. I think the figure he's quoting is for 44.1kHz sample rates. 
 
The term "zero-latency" originally referred to zero latency contributed by the computer itself. However that term has lost its original meaning over the years and now is a generic phrase meaning "you can monitor without having to go through the computer." However monitoring the input means you won't hear any of the effects contributed by the computer, like amp sim plug-in effects. This is why for guitar players, "re-amping" is popular. You can monitor yourself through a guitar amp with true zero latency (unless you're going through DSP in the amp or any effects), then modify the dry sound recorded in the computer at your leisure.

Lets put things into perspective here 2 ms is equivalent to 2 feet from a speaker. 10 ms is about 10 feet and so on. 

John
Lets put things into perspective here 2 ms is equivalent to 2 feet from a speaker. 10 ms is about 10 feet and so on. 

Yes, let's put things into perspective 2 feet is about 18" longer than the distance between a singers mouth and their ears. A 2 millisecond delay means that a vocal returned through a digitized headphone monitor mix takes 4 Times as long to get to the ears as many singers are used to.
 
If it wasn't such a big deal, In Out box manufacturers would supply more accurate specs rather than gloss over the truth. ;-)

To not hear any audible latency when recording, all you need to do is get your round trip latency to under about 10mS, give or take. 
 
To do this, all you need is:
1. A PC that can handle it, including your MOBO.
2. A hard drive that spins at or over 7200RPM and is dedicated for audio only.
3. A sound card that has good drivers written for it
 
Thats it. If you have all 3 of these, then you can achieve it
 
CJ
 

Or from another perspective, for your band to play together to within 2 ms of accuracy, you would all need to sit on the drum throne together :) 

mike_mccue

John
Lets put things into perspective here 2 ms is equivalent to 2 feet from a speaker. 10 ms is about 10 feet and so on. 

Yes, let's put things into perspective 2 feet is about 18" longer than the distance between a singers mouth and their ears. A 2 millisecond delay means that a vocal returned through a digitized headphone monitor mix takes 4 Times as long to get to the ears as many singers are used to.
 
If it wasn't such a big deal, In Out box manufacturers would supply more accurate specs rather than gloss over the truth. ;-)

You're right. However when a singer is not using headphones, such in a live performance or for the centuries before electronic amplification and recording, singers and musicians in general all had latencies due to the fact they were separated from one another. One reason large orchestras developed conductors.
 
We all deal with this issue and do so automatically. When some one speaks to us from afar 10 feet or more we don't hear latency yet its there. Their lips move and 10 ms later we hear the sound.
 
Over the eons we have trained ourselves to ignore the delay and hear it as instant.  Also physiologically we have internal latency as well. Some call it reaction time. It varies from person to person. Age also has an impact too.
 
In most cases 10 ms or less is not a bothersome latency. Some find 14 ms to be acceptable. 
 
   

Thanks. I understand that interfaces with an internal mixer (referred to as a dsp mixer) do the job fine, although it is not Zero latency. I was considering to buy either a new interface or a cheap mixer, so thanks for your input.
Jan

jrom
Thanks. I understand that interfaces with an internal mixer (referred to as a dsp mixer) do the job fine, although it is not Zero latency. I was considering to buy either a new interface or a cheap mixer, so thanks for your input.
Jan

I use a digital mixer. I have for many years.