Excellent posts - Thanks Jim, Robert (oh no, your name's in bold again!), and Scook for replying.

I'll tell ya, I haven't worried about latency in so many years since all is working fine for me.  But the current posts about latency got me curious, since my round trip report has never made sense to me.

But you can see from my posts - it's been so long since I've thought about latency, it slipped my mind when I started this thread that of course round trip isn't what's involved when recording MIDI.

HOWEVER - I never have any trouble recording vocals.  When I record audio, a mike is the most common source.  I put on my headphones, listen to track playback, and sing away without a problem.  I thought there was delay compensation involved or something - all I know, there's no delay.

CLEARING UP THE ALESIS DRIVER QUESTION:

--This unit (supplanted by the "Express" version of the same interface) does have its own ASIO driver, and that's what I use primarily.  However, huge caveat, the driver doesn't work in 64 bit.  As you discovered from your search, Robert, Alesis just points users to ASIO4ALL - IF they're working in 64 bits.  So, when I have 64 bit Sonar open, ASIO4ALL does kick in.  But I'm still doing most of my work in 32 bit, so use the unit's native driver.

Jim, you refer to "the driver's hidden safety-buffer," and how the user often doesn't have access to it.  Maybe that's what I'm looking at when I open the Alesis control panel?

Since more info was asked for, here's everything that seems pertinent when opening Sonar's Preferences:
 
--Input Drivers - ALESIS IO|2 USB ASIO Input (when in 64 bit - ASIO4ALL v2io|2 1)

So, Playback Timing Master and Record Timing Master are both the ALESIS IO|2 USB

Sampling Rate 48

Mixing Latency - 5.3 msec - 256 samples
 
Playback and Recording

ASIO
Use Multiprocessing Engine (6 core machine)

MIDI Devices

io|2 for inputs and outputs - and my A-800 Pro keyboard/controller

MIDI

Number of Buffers 64        

Playback- Prepare Using 500 Millisecond Buffers (as per the oft repeated advice here on the Forum)

ASIO Settings in ALESIS panel:

Buffer Size 256

Number of Buffers 8 - Jim, is that the "hidden safety-buffer?"

SO - all I know is I have no problems.  Ever since I've had this interface, and that's Years, Sonar has always hovered around showing 50 msecs as the roundtrip.  Shrug.  I experience no lag no matter what I'm doing, so I'm happy.  I'll just have to accept the mystery of it all!

Randy

I think it's possessed :)
 
Regardless of the numbers being reported, if it is performing as needed for you, have a blast.
 
And thanks for clearing up the drivers and driver mode weirdness.
 
Bob Bone
 
 

When recording audio, is it possible the audio being recording is directly monitored ? If so, this would explain the near zero latency monitoring while recording audio.

I was thinking that very same thought.  I too am wondering if that is what is happening.
 
Bob Bone
 

Hi Randy,
 
Are you monitoring via hardware or software?
If you're monitoring via the onboard features of your audio interface, then that's near zero latency (regardless of the ASIO buffer size).  In this case, the audio interface is taking what arrives at it's input... and immediately shooting it to an output.  This would explain the high round-trip latency figure... while still being able to comfortably monitor.
 
Round-trip latency is really only a factor if you play/monitor in realtime thru software based EFX/processing.
ie:  You're playing a DI electric bass/guitar while monitoring in realtime thru an AmpSim plugin.
 
No, the number of buffers has nothing to do with the driver's hidden safety-buffer.
That's just it... it's typically hidden (you have no means of adjusting it).
Some audio interfaces use a large hidden safety-buffer with the logic that it reduces odds of problems upon playback under less than ideal circumstances (ie: a poorly configured machine).  But... that extra buffering comes at the expense of higher (much higher in some cases) round-trip latency.
 
 

I think my head's full!  Thanks for all the info, tips and conversation - As you said Bob, things are performing as per my needs so, fine.

This will be helpful for me to reply to:
 
Jim sed - "Round-trip latency is really only a factor if you play/monitor in realtime thru software based EFX/processing."

I never use any plugins while recording.  Dry bone, raw audio is all I want, and certainly know from experience that many (not all?) plugins are going to give one instant latency - why live with it?  I know many  musicians, probably especially guitarists, find it a complete drag to not hear FX while playing - quite a challenge to do a great lick and feel how it's going to be in the mix, if all you're hearing is a live, unprocessed "plunk."  But I'm not a guitarist, and for what I'm doing, using lots of virtual instruments, it's no hardship to just focus on the notes, the music itself, and then have fun later adding me reverb and whatever else seems good. 

Answering another thing brought up:

This interface, like most, has a Direct/USB Monitor Mix knob - it's called different things on different units.  But it's very rare for me to turn it to Direct - Yes, that gives me the straight signal before any trips to and from the computer - but that's all that's heard, the new signal going in - If I wanted to monitor the tracks already in Sonar, I'd need to get into a monitor send, external mixer etc --not into doing that, no need for what I do.  So the knob stays at the USB position.  I listen to the tracks, I sing, I'm happy.

Thanks again.

Randy

I would imagine most never turn the direct/usb knob all the way to direct. This is a mix knob controlling the ratio of direct to usb signal. The knob is there to eliminate the need for a mixer to hear the DAW while using direct monitoring. But as you say, it is all academic.

Latency is very confusing topic and I don't think half the people out there using an under $300 interface even realize the unit probably is like Randy'sv with a TRTL of 25 ms and up. Like my Focusrite Scarlett, people rave about them, but they actually suck at RTL. Mine is 28ms on a good day. But as Jim said, this matters not if your not listening to your input via the outputs.
 
There is the Centrance test you have to run to find out but appearantly Sonars reported RTL is good for most but might not report the so called hidden buffers.