HD500X - Latency / Loopback test?

[JohannDaart]

After connecting HD to my PC through USB, I had no problems setting up Line 6 ASIO driver in my DAW (Ableton).

 

But when I record guitar onto one track, while playing a backing track on another track, there's some misalignment.

Most DAWs (Ableton, Logic, Reaper) have an option called "Driver error compensation" (Ableton) or "Input manual offset" (Reaper) that allows to correct this misalignment. 

 

To measure this offset, its necessary to perform "loopback test". Connecting Output of the device to its Input, playing a sample sound in DAW while recording it, then measuring the timing difference between a sample and recorded sample in milliseconds - that's the needed offset.

 

Have you guys tried doing it? The problem is that POD has only instrument inputs (so plugging 1/4 line level outs into them seems a bad idea), while audio interfaces inputs can switch between line level and instrument modes...

 

Or maybe there's something that I've missed...

[hurghanico]

Actually no testing is needed if the settings are in a certain way.

 

Any decent DAW should automatically compensate for the amount of latency in the system in use, and if you only use the hardware direct monitoring (POD) you should not have any problem of synchronization between the recorded tracks and the one in recording.

 

The synchronization problems/tracks misalignments occur only when instead of the direct hardware monitoring (POD) you use/enable the monitoring of the recording track in the DAW as auditory reference for recording, for example if you need/want to monitor live a plugin loader of impulse responses.

 

So in conclusion I recommend enabling only the direct hardware monitoring (POD), and applying any plugins if necessary only later on the track already recorded.

 

To enable the direct hardware monitoring (POD) you should use the Line6 ASIO control panel,

to disable/enable the DAW track monitoring you should use your DAW dedicated commands/buttons.

 

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All about POD HD500/X

help and useful tips

[JohannDaart]

Yes, I understand, that there's a difference between DAW monitoring (it has latency that can't be eliminated, for example when "reamping" dry signal from POD) and direct monitoring (that should have no latency).

 

In my case, there's a slight latency while direct monitoring.

 

From what I've learned, while direct monitoring, just as you wrote, every DAW compensates recordings for latency that is reported by unit's drivers. So if a driver says its 20ms, DAW will compensate for 20ms.

But more often than not, drivers are not providing the exact correct latency. Usually it's off by +/- 2-4 ms.

 

There's a good video about this:

 

 

I just noticed, that I can't change buffer size in Line 6 ASIO driver panel. It keeps reverting to 1024... I'm on Windows 8.1, I think something is off with the driver. 

I will try reinstalling it, but I don't think it will solve this "frozen" buffer size problem, because I know that I've installed everything properly :(

 

Anyway, on HD500X, using some settings, is there a way to connect (line level) output to (line level) input?

Guitar Input is obviously instrument level.

What about AUX or MIC? Can they be set to line level?

[hurghanico]

20 hours ago, JohannDaart said:

Anyway, on HD500X, using some settings, is there a way to connect (line level) output to (line level) input?

Guitar Input is obviously instrument level.

What about AUX or MIC? Can they be set to line level?

 

AUX and MIC are instrument level and there is no setting setting to change their behavior.

However one the rear panel there is the RETURN input which depending on the dedicated physical switch setting can work at LINE or INSTRUMENT (STOMP) level, but to use it you need to put the FX LOOP block somewhere in the chain.

 

I must say that I find it hard to believe that a human listener is able to clearly perceive a misalignment of +/- 2-4 ms.

 

Luckily the listeners get the audio, but if instead they were to see the waveforms in millisecond detail along the time grid what would they think of who recorded those tracks? ..

I think it would be fun

 

_______________________________________________________________________________________________________________________________________________________________________

All about POD HD500/X

help and useful tips

[JohannDaart]

1 hour ago, hurghanico said:

I must say that I find it hard to believe that a human listener is able to clearly perceive a misalignment of +/- 2-4 ms.

 

I agree, RME and Zoom interfaces on USB3 have below 5ms latency while DAW monitoring (reamping with live plugins) and that's truly unnoticable.

So those last 2-4 ms of recorded track misalignment while direct monitoring are nothing.

Getting recorded tracks perfectly aligned in a DAW is a nice thing, though.

 

But it turns out that something was off with my Line 6 driver (4.2.7.7). It was "frozen" (no ability to change settings).

I thought that simply reinstalling it won't make a difference (for buffer settings and this latency misalignment)... but it did.

 

I just clicked "reinstall" in Line 6 Monkey and everything works properly now.

 

Thank you for the tip about line level FX Loop, I haven't though about it!

I will do this "loopback" test out of curiosity anyway ;)

 

You are really a life saver hurghanico! I think you have more practical knowledge about HD than Line 6 ;)

[JohannDaart]

I did the loopback test, turns out the driver is wrong by -0.53 to -0.63 ms, the real latency is variable by 0.10 ms. 

 

That's miniscule, but at least I've satisfied my curiosity or... OCD haha ;)