Latency seems to be the topic of the hour.  I really haven't been concerned with latency for a long time, everything's running smoothly for me.  BUT - it's always been a mystery to me why what I'm told in the Sonar Preferences audio settings sounds like I should have a problem when I don't.

Here's some info - Maybe an expert here can 'splain to me what the deal is.

Here's just one of the current threads where latency is discussed:

"Experienced user, still not having it with Cakewalk Sonar products"
 
On that thread, Robert Bone said:

robert_e_bone
I still think your Total Rountrip Latency of 18 milliseconds is too high for good recording without noticeable lag.

I believe the audible lag detection point is something like 14.5 milliseconds or thereabouts.  It was some German guy that figured that out, if memory serves.

I always recommend keeping settings to where for recording purposes, the Total Roundtrip Latency reported by Sonar is around 10 milliseconds, or just under that...

 
Here's what's mysterious to me:

--When I've engaged my settings to use while recording, Sonar says that I have--
 
"Effective latency at 48kHz/stereo 5.3 msec

Total Roundtrip:  53.3 msecs"

When I play a soft synth, the response is immediate.  There's no detectable lag, so playing piano, playing anything goes smoothly as it should.

Then when I'm mixing, I open my Alesis iO|2 interface and move the slider up so that my "effective latency" is around 10 or 11 msec, and that works great for mixing.

WHY, with my recording setting, does it say my roundtrip is a whopping 55.3, when Robert says, as everyone says, that roundtrip needs to be under 10, or the delay will be heard and make live playing impossible?

Is it because my interface reports differently than most interfaces?

All I know is that I've always had a total roundtrip report of around 50 msecs, and I've always just shrugged it off since everything's working fine.

What's the story, what's the deal??

Randy

WHY, with my recording setting, does it say my roundtrip is a whopping 55.3, when Robert says, as everyone says, that roundtrip needs to be under 10, or the delay will be heard and make live playing impossible?

 
If one way is about 5msecs and roundtrip is 55.3, then something is really really off. Those numbers do not make sense
 
Also, its probably because you are not Actively recording that track. Latency for recording will not be noticed when track is just armed for recording. You need to actually be recording.
 
CJ

CJaysMusic

WHY, with my recording setting, does it say my roundtrip is a whopping 55.3, when Robert says, as everyone says, that roundtrip needs to be under 10, or the delay will be heard and make live playing impossible?

 
If one way is about 5msecs and roundtrip is 55.3, then something is really really off. Those numbers do not make sense
 
Also, its probably because you are not Actively recording that track. Latency for recording will not be noticed when track is just armed for recording. You need to actually be recording.
 
CJ

Thanks for the reply, CJ - Before posting, I opened Sonar to make sure I had the numbers accurate.  That's what it says, 55.3 roundtrip - But what I'm saying is that this is what Sonar has Always said in that audio settings dialogue, and I've had this same audio interface for about 7 years.
 
I'm talking about recording tracks, not just arming them.  With those settings I've always been able to record either MIDI or live audio with Zero detectable lag - with "effective latency" reported at 5.5
 
My theory is that this Alesis interface just isn't being interpreted correctly by Sonar, and that 5.5 is actually my roundtrip figure.  When I have my Mix setting engaged, and my one trip is at 10 msecs - of course I can hear the lag then, and it would be impossible to play a keyboard with that.  That kind of latency is what people are talking about when they're reporting being unable to play accurately due to lags - but I never attempt to record with the settings moved up like that for mixing.
 
Randy

You are running at 48kHz with 256 buffers according the the "Effective latency at 48kHz/stereo 5.3 msec".
These figures are the results of the a simple calculation:
Effective Latency = NumberOfBuffers / SampleRate
in this case
.0053 = 256 / 48000
 
The round trip latency is the sum of the ASIO reported input an output latencies. This relies on information from the interface in addition to the calculated latency.
 
I would imagine most would find 256 buffers at the edge for monitoring through the DAW.

scook...The round trip latency is the sum of the ASIO reported input an output latencies. This relies on information from the interface in addition to the calculated latency.
 
I would imagine most would find 256 buffers at the edge for monitoring through the DAW...

Thanks for the post, scook - Yes, 256 is exactly where I have things set for when I'm recording.  You've put "reported" in bold, because you're suggesting that this Alesis unit isn't reporting figures in a way Sonar expects?
 
Randy B.

I found nothing about the interface so can't say how/what the Alesis reports. The round trip is the sum of the input and output values , each value is reported separately just above the total. The round trip only happens when an audio signal is coming from the audio inputs interface and returning to the interface. When playing a soft synth the audio is originating in the DAW, it is not coming from the audio inputs on the interface.

I haven't seen my name in bold for a long while.  Yikes! :)
 
I looked up the specs on the interface: http://alesis.com/io2
 
Hopefully, I have the correct one.
 
IF so, it looks like this interface does NOT have its own ASIO drivers, and instead relies on ASIO4ALL.  If you go to the above link, then click on Docs and Downloads, you will see what I am talking about.
 
SOOOO, I am quite confused.  Please tell me what Driver Mode you are running in Sonar, and if you are using ASIO4ALL for your audio drivers for this interface, and also what all of your settings are.
 
Thanks, 
 
Bob Bone
 

I believe the ASIO Reported Latencies are only shown when SONAR is in ASIO driver mode. Running ASIO4ALL may explain why there is such a disconnect between the calculated latency and the reported latency. Don't know for sure though don't use it.

Scook - yes, you are correct.  ASIO reported latency values are only posted in Preferences>Audio>Driver Settings when the Driver Mode is ASIO.
 
I too suspect that the culprit here is again ASIO4ALL - possibly not reporting things correctly, or who knows what.
 
Bob Bone
 

Round-trip latency is the sum of the following:

• ASIO input buffer
• ASIO output buffer
• A/D D/A converters
• The driver's hidden safety-buffer

So if you have your audio interface's ASIO buffer size set to 64-samples at 44.1k...
 
The ASIO input buffer = 1.5ms
The ASIO output buffer = 1.5ms
The A/D and D/A converters = ~1ms
The driver's hidden safety-buffer is the X FACTOR
 
Better units use a small safety-buffer (RME, MOTU, Lynx)
Some units use a large safety-buffer
 
If your audio interface uses a large safety-buffer, there's not much you can do about it.
Most safety-buffers are hidden from the end-user... so there's no means of adjusting it.
 
As a point of reference, the best audio interfaces yield ~5ms round-trip latency at a 64-sample ASIO buffer size/44.1k.
 
If you're playing a soft-synth, you're not dealing with round-trip latency... but rather one-way (playback) latency.
 
To effectively overdub (monitoring thru software while recording), you need to keep round-trip latency as low as possible.
I find anything above 6ms uncomfortable. 
Anything above 10ms feels like you're playing thru molasses.
 
Don't believe it?  Here's a simple test (assuming your audio interface has low round-trip latency):
Insert a delay processor set 100% wet.
Adjust the delay time to 50ms (to make the effect very obvious).
Try to play/monitor in realtime thru that 50ms delay.
Drop the delay time to 20ms and repeat.
Drop the delay time to 10ms and repeat.
Drop the delay time to 5ms and repeat.
Finally, disable the delay plugin and repeat.
If you're playing/monitoring high-transient instruments (bass, drums, guitar), you can really feel the lag of the extra latency.