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LATENCY, mostly TOTAL LATENCY
#1
TOTAL LATENCY, about

We begin with some serious fun - for people hit by latency
LATENCY demonstration in SESSION - by distinct clapping, tapping on microphone or whatever. 60-70 bpm:

1. One person start - and keep on, steady.
After some seconds all other try to follow excactly. One by one, maybe. Whatever.
2. One person start ...
Only one other person follow ...
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JamKazam terms:

20 milliseconds and below is called GOOD and the dot is GREEN
Between 20  and 35 is called FAIR and the dot is YELLOW
Between 35 and 50 is called POOR and the dot is RED
50 and over is called UNACCEPTABLE and the dot is RED
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10 milliseconds TOTAL LATENCY between (two) people is like playing 3,5 meters apart from each other. Very few people can hear/notice such low latency as 10 ms.
20 milliseconds is like 7 meter apart. All average human beings can hear/notice 20 milliseconds delay - under best condition.
50 milliseconds is like 17,5 meter apart.
100 milliseconds is like 35 meter apart.
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Playing together in "real" real time is impossible

There will always be some latency, delay - from audio interface and from the internet connection.
Audio interface latency can be as low as 2 milliseconds - depending on quality and so.
Internet latency can be as low as 3 milliseconds, depending on quality - and distance between people, quantity, so to speak.
--- VERY important is the so called PING - the "answer time" from PC to internet provider and back,
I have 13 ms PING, for example. It can be so low as 2 ms.

Example: 2 x audio interface = 4 milliseconds.
1 x internet connection = 3 milliseconds
TOTAL LATENCY = 7 milliseconds
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The best connection I have is from one of my computers to another of my computers on the same router/LAN. Two accounts is needed for that, of course. The TOTAL LATENCY is around 10 milliseconds.

My second best connection is with a person 100 kilometers away. The TOTAL LATENCY is 18 milliseconds.

To people in Australia (I am in Denmark) the TOTAL LATENCY is 200-300 milliseconds - that is only for very, very, very slowly and loose singing.

To USAs eastcoast it is usually 75-80.

To Californien 110-130

Thailand around 150.

My relatively best connection is with one 2.000 kilometer away in Norway. The TOTAL LATENCY is about 27 milliseconds.

Latency in my audio interface is by the way 4.2 milliseconds.
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Having the same internetprovider gives usually lower internet latency.
Maybe 5 milliseconds in most cases.
Maybe 20 in some cases.

What is the usual internet latency between for example?

1. Portland, New Hampsh i re and New York
2. Kansas City and Denver
3. Seattle and Chicago
4. San Antonio and Panama City
4. Dallas and Los Angeles
6. Jacksonville and Miami
7. New York to Kansas = 32 ms - as one example. audio gear included

Other examples is very welcome
- from all over the world
Not audio interface latency included, please
- only internet latency
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#2
A safe path to the lowest possible TOTAL LATENCY - to me, as an easy example:

Use Behringer UMC 404 (or 204HD, 404HD) - ASIO driver - buffer size = 8 samples

Result = good sound and low latency, 4.2 milliseconds

Use the best internet provider out there.
Upload is more important than download.
5-6 Mbps (about 0.4 Mbps per person*) upload is needed for a session with 8. Video excluded.
Very crucial is the so called PING ("answer time" from computer to internet provider and back - the expression comes from the world of submarines and the SONAR, I believe)

If possible, use a provider that has direct access to Stofanet, a company in Denmark, IP.

X Move to Holte town in North Zealand, Denmark. Within 5 miles of me.
Result: about 15 milliseconds

Y Come visit and use my other computer
Result: 12 milliseconds

Z Move in as my neighbor. Maybe we can connect directly to each other with a smart cable
Result: maybe 9 or 8.6 - and extremely stable

* In session look on the stats by hover over the dots in the tracks - and see data for audio transmission; in/out
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#3
Hans, Does the lever of USB (2.0 vs. 3.0) make a difference in your experience? Thanks, M
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#4
I have never tried in a USB3-port

My understanding is that USB2 can carry more than 100 mono signals in studio quality at the same time.

How much USB3 can carry I dont know.

But 100 mono signals should be enough.

Beside of that it is very few audio interfaces that use (support?) USB3, I think. As a matter of fact, I have only seen USB2 - as far as I remember.

None of my interfaces is USB3 - they are USB2
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#5
And regarding latency, I think the difference between USB2 and USB3 is very little.
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#6
(04-04-2020, 01:29 AM)Hans Peter Augustesen Wrote: Hans - great posts man !!  if there is good total latency < 20 ms for each of 3 players, i understand this is pretty good.  But there seems to be a lot more delay in some cases 1/2 second.   So can this be due to high jitter which on a couple of users it spikes to 250ms?  if this is an issue - anyway to get this lower?  
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#7
kmcderm3399 - Thank you, man

I dont know much about jitter.

Jitter is both in gear and internet connection.

I assume it is a kind of buffer, so to speak, hm!

Jitter can be lowered by different methods, yes.

Read about that elsewhere in forum. Maybe I can find some.

"1/2 second"!? - delay/latency

I have seen 25.999 milliseconds. And 20000ms. And 12000ms. That is usually with wireless connections, bad connections.

250ms is normal Denmark-Australia. Moskva-Chicago = 150ms.

Copenhagen-Lund, Sweden = 20 milliseconds

As I wrote (almost):

"Audio interface latency can be as low as 3.4 milliseconds - depending on quality and so.
Internet latency can be as low as maybe 4 milliseconds, depending on quality - and distance between people, quantity, so to speak.

Example a) 2 persons 60 miles apart, fast gear + fast internet:
2 x audio interface = 6.8 milliseconds.
1 x internet connection = 4 milliseconds
TOTAL LATENCY = 10.8ms

Example b) 2 persons 3000 miles apart, slow gear + slow internet:
2 x audio interface = 26ms
1 x internet connection = 44ms
TOTAL LATENCY = 70 milliseconds

You see there is many parameters ...

In fact: the most variable is the location.
Scandinavia has the best connections as a whole - next to South Korea, I think.
Great Britain for example is `famous` for bad connections - compared to their neighbours.
USA is very varied. And so on.
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#8
What is the more excact purpose with your post, anji01 ?

It has surely nothing to do with latency.

Then what, anji01 ?

In fact is is very irrelevant.

It has nothing to do here, so to speak

Hm!
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#9
5 or 6 different items can affect total latency. If you think you may have a latency problem, a good place to start is to ping some common sites and see what their latency is via a staring network ping. As a sample I am getting 22-28ms pinging the Google DNS server 8.8.8.8 and around 40ms to usatoday.com ... but, I was seeing 200-400ms before I paused my cloud backup application "Backblaze" .. I believe Backblaze was causing buffer bloat on my network (I have about 200MB into the house and 11MB out) and it was causing latency for all packets leaving the house. Which is to say that BackBlaze (and I assume most of the cloud backup services) running on any computer in your home network will cause latency issues for anyone in the home .. for me, I just decided that I will pause Backblaze whenever I use JamKazam. I use the Mac client and a wired network.
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#10
Very good you are pointing at the PING

I have now added to the startpost:

"--- VERY important is the so called PING - the "answer time" from PC to internet provider and back,
I have 13 ms PING, for example. One the other day had 4 ms (not joking)"
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