Latency of amp modelers

stdout said:
Further down in the paragraph you quote it says - Conversely the keyboard, electric guitar, and electric bass instruments have little or no direct sound. Although they will have no physical artifacts such as comb filtering, psychophysical effects may still be present.

And again there’s no effect from comb filtering when using IEMs. But believe it or not I have no axe to grind here and also no latency issues with my FM3. What I do question is whether the 5 ms floor claimed as absolute is indeed definitive. It wouldn’t be surprising if that number originated in telephony where for comprehensibility latency is a major consideration. But musicians are a non-representative subset of the population when it comes to hearing and listening. And even within this subset there is great deal of variability. So when some musicians speak of ‘feel’ when discussing analog and digital I wonder if they may be referring to a subliminal effect of latency perception. But I’ll drop this in good faith now that the acolytes are flocking in.
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I think you are conflating the ability to detect whether or not two signals playing back have relative latency versus being able to detect latency between a sound you initiate (eg with the pick) and it's onset through the speaker.

You can easily test yourself on the former by taking a mono track, send it to a stereo output, and delay one side. Can you hear 1ms delay? 5ms?

On the latter, plug in to an amp, move 10' away. Can you feel that delay compared to being 1' away?

If you stand 10' behind the speaker, do you hear the sound 10ms before you pick?
 
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stdout said:
So when some musicians speak of ‘feel’ when discussing analog and digital I wonder if they may be referring to a subliminal effect of latency perception.
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imo, this is key, but few seem to want to consider it here - I often hear guitarists say they don't like latency as much because of the way it feels (feeling a gap on pick attack which may become subliminal as latency goes down), as much or more as I hear them say they don't like hearing a gap between the acoustic sound of their guitar and the output of the modeller (this only audible if playing at low volume with larger latency amounts).

As mentioned above, its unfortunate the vid in the OP is presented as a pissing contest that prompts manifacturers
and invested followers to raise defenses, as opposed to setting the stage for meaningful discussions that enthusiasts can learn from and participate in. Pissing contests get the most likes
I guess.
 
stdout said:
I have no problem with people disagreeing with me and I’m willing to be wrong. Cliff’s criticism of my use of the first paper is fair. And I appreciate he took the time to read part of the second paper though I think he stopped short of the point before responding as I pointed out in my last post. On the other hand I do take offense when someone piles on with condescension without adding anything to the conversation. And I don’t think I’d be the first to observe that some of the behavior seen here verges on the cult-like. In my opinion Fractal products are second to none. But I guess it’s my problem that like Groucho, I’d never want to belong to a club that would have me as a member.
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Well, yeah :). I'm sure it felt good to insult those forum members, but that still leaves your point unproven. The Lester paper shows an 85% confidence level for the assertion that latency below 5 ms can't be detected for guitarists through IEM. Basically one subject did not hear latency at 5ms and the other might have heard something, but it's hard to say. I wouldn't go so far as to call that support for your idea that latency below 5ms is detectable. In fact, it could be considered proof that your point is incorrect.
 
Dave Merrill said:
Yeah no eating lab animals here either, I just didn't want to be a part last of that whole ecosystem.
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Must admit, I was not much engaged during grade 7/8 science class - busy with the spitball wars that would occur during the dissection instruction films - amazing how far a small wet ball of paper will travel in a straight line when propelled with some air pressure through the tube of a circa 1970s Bic pen.
 
FractalAudio said:
Research has repeatedly shown that humans cannot detect latency of less than 5 ms.
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At my rehearsal room, years ago, I did an unscientific, but illuminating, latency test, where I took a long guitar cable, stood right in front of my 4x12 and played while moving directly back from it until I could definitely discern a lag due to latency. The onset was somewhere around ~13+ feet or so, and when backed off to ~15+ feet the latency was starting to be 'a problem'. I've played ~10 feet away from my 4x12's many, many times over the years and never even remotely felt disconnected.
 
GlennO said:
Well, yeah :). I'm sure it felt good to insult those forum members, but that still leaves your point unproven. The Lester paper shows an 85% confidence level for the assertion that latency below 5 ms can't be detected for guitarists through IEM. Basically one subject did not hear latency at 5ms and the other might have heard something, but it's hard to say. I wouldn't go so far as to call that support for your idea that latency below 5ms is detectable. In fact, it could be considered proof that your point is incorrect.
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As I said before, my interest lies in the question as to whether 5 ms is a definitive latency floor. My reading of the Lester paper says it isn’t and I take it that 5 ms has been long used as a useful engineering rule of thumb. The following chart from the paper characterizes by instrument the range of latencies the subjects found acceptable. To me this was non-intuitive. I wouldn’t have expected different instruments to demonstrate such a varied range of manageable latencies.
D9A4F37B-0827-41CD-B10A-A80239D46163.jpeg
 
stdout said:
As I said before, my interest lies in the question as to whether 5 ms is a definitive latency floor. My reading of the Lester paper says it isn’t and I take it that 5 ms has been long used as a useful engineering rule of thumb. The following chart from the Lester paper characterizes by instrument the range of latencies the subjects found acceptable. To me this was non-intuitive. I wouldn’t have expected different instruments to demonstrate such a varied range of manageable latencies.
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Those lowest values were only achieved when using cues like comb filtering, which as was pointed out above, is irrelevant for guitarists playing through a modeler. Look at the raw results for guitar through IEM. It definitely shows a guitarist cannot reliably detect latency below 5 ms.

There may be studies out there that support your point, but the studies you are citing do not. I think one reason such a study is hard to find is because it's already quite easy to demonstrate the inability to detect latency below 5ms on your own. Just have a friend blindly and randomly insert a 5ms delay in your signal chain. I have no doubt some people can detect such a delay, but most people cannot.

P.S. The interesting part of the Lester paper is not the guitarist inability to detect latency below 5ms. The interesting part is the way latency in IEM and wedges is perceived differently.
 
Stratoblaster said:
At my rehearsal room, years ago, I did an unscientific, but illuminating, latency test, where I took a long guitar cable, stood right in front of my 4x12 and played while moving directly back from it until I could definitely discern a lag due to latency. The onset was somewhere around ~13+ feet or so, and when backed off to ~15+ feet the latency was starting to be 'a problem'. I've played ~10 feet away from my 4x12's many, many times over the years and never even remotely felt disconnected.
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was this a real amp or modeller? if real amp, this speaks to the compounding aspect that I think is also being overlooked here among the white papers. If at 10ft you are ok in front of a "no latency" real amp+cab with 3ms of "latency headroom", your equivilent modeller rig needs to have ultra low latency (3ms) in order to support your preferred 10ft proximity. This low latency requirement in the modeller is, in this case irrelevant of whether or not one can sense a 3ms difference or not. Same consideration wrt runnlng outboard gear from a modeller. Investing in a low latency unit like Axefx is worthwhile for reasons other than your ability to sense 5ms-, so in this way, I guess the latency pissing contest is worth considering in one's modeller purchase research.
 
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sprint said:
was this a real amp or modeller? if real amp, this speaks to the compounding aspect that I think is also being overlooked here among the white papers. If at 10ft you are ok in front of a "no latency" real amp+cab with 3ms of "latency headroom", your equivilent modeller rig needs to have ultra low latency (3ms) in order to support your preferred 10ft proximity. This low latency requirement in the modeller is, in this case irrelevant of whether or not one can sense a 3ms difference or not. Same consideration wrt runnlng outboard gear from a modeller. Investing in a low latency unit like Axefx is worthwhile for reasons other than your ability to sense 5ms-, so in this way, I guess the latency pissing contest is worth considering in one's modeller purchase research.
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I did this with a real amp; a JCM-800 head. FWIW I've played many times several feet in front of my Fractal units through a CLR and have never felt a disconnect due to latency. I guess that modeler latency does indeed lower the distance away from the speaker that perceptible latency would become apparent though as you've said...
 
GlennO said:
Those lowest values were only achieved when using cues like comb filtering, which as was pointed out above, is irrelevant for guitarists playing through a modeler. Look at the raw results for guitar through IEM. It definitely shows a guitarist cannot reliably detect latency below 5 ms.

There may be studies out there that support your point, but the studies you are citing do not. I think one reason such a study is hard to find is because it's already quite easy to demonstrate the inability to detect latency below 5ms on your own. Just have a friend blindly and randomly insert a 5ms delay in your signal chain. I have no doubt some people can detect such a delay, but most people cannot.

P.S. The interesting part of the Lester paper is not the guitarist inability to detect latency below 5ms. The interesting part is the way latency in IEM and wedges is perceived differently.
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The paper says that comb filtering doesn’t apply for keyboards, guitar and bass with wedges. That would apply to IEMs as well. So I take the table figures to be valid for those instruments.

“the keyboard, electric guitar, and electric bass instruments have little or no direct sound. Although they will have no physical artifacts such as comb filtering, psychophysical effects may still be present.”

However on the whole, because of the sample sizes and the issues associated with the subjects self-reporting their perceptions and despite the experiment design and methodology, I’d treat much of the paper as little more than anecdotal.
 
the issue gets worse if you have to add latency to an already existing latency....nobody hears 3.3 or 4ms alone, but together with natural latency (by distance) or latency by another unit, things can get noticable
 
Nobody is discussing the real solution ?

Just heat up the room a few degrees boom less latency…

Bill Murray Drink GIF
 
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