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Latency after bus routing..Help!


Khorshid

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Best is to show us a screen shot. Because I never ran into such an issue with any of my 200 plugins. And I even route to busses via Out and Sends, those busses I route to other busses.

 

Also make sure you don't have 'Low Latency Mode' turned off. Maybe that causes latency issues with buss routings, not sure though.

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I'm having trouble uploading the image. But the latency button is on and set to "ALL". Another problem I'm having is when I record midi from an external source there is no latency during the actual recording but when you try to playback and listen to what you recorded there is so much latency that it is completely off beat. Once you record the midi track into audio it is magically is ON beat again. Ruins my workflow completely.
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That MIDI latency issue after recording I know too, but don't have any solution at hand. Did you also realize that the more plugins the session has, the bigger the latency? It's not a steady/fixed latency... I hate that. It ruins my workflow too. Gladly I don't record very often MDI synths. Most customers don't want to pay the extra time ;) And the extra time you need to get rid of that latency :(

 

Probably one of the mods know a solution for this MIDI-latency issue.

 

Back to topic. Turn off the "low latency mode". It is in the transport bar. If you don't see it, right click on the transport bar and start customizing it. There you'll find a checkbox for the "low latency mode". Check it so it becomes visible in the transport bar. Make sure it isn't activated.

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I usually have it set "ON" because if I don't the latency will get worse. That is when I record normal software midi inside Logic. But as soon as I use external midi the problem gets much worse and turning "off" and "on" doesn't help in any way. But I'm really surprised that with the technology we have in 2015 it's not even possible to fix a simple thing like this. Do I need to get more rams or what? I have 4GB installed.
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Doesn't have to do anything with RAM. And there will be always some kind of latency. This is something that will always come along with DAWs. Especially as more complex the routing gets the more difficult is it to align all of those signals properly, plus all the plugins that involve different amount of latencies and some of them might even change that value dynamically, e.g. when automating certain values. You cannot have it all mate.

 

Use "Low Latency Mode" only when playing or recording soft- and hardware synths. But during mixdown, arranging, etc. you don't need this mode. Just turn it off. This mode anyway disables all sends of the selected track, so it becomes fairly useless when you are not playing anything, which will be anyway most of the times.

 

Set a shortcut for that mode, so you can toggle it on/off faster.

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External synth..

 

Software monitoring?

 

Direct/mixer monitoring?

 

No-one can give you a definite answer to your external synth's "MIDI latency" problems unless they know how you're monitoring. And it's probably not MIDI latency, but PDC/PLC latency and/or Recording Latency Compensation (RLC) that's the problem.

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Yes I do that all the time. When I'm recording external midi it's "ON" but when I playback to listen I turn it off for it to be on beat. That is such a messed up workflow. It still amazes me that we have been to the moon and back and we can't even fix this. How has anyone in this industry ever created a track from external sources without going nuts.
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When recording audio you will have to either use Low Latency Mode or You can turn off Software Monitoring and just use monitoring from the interface.

 

 

If he's software monitoring through Logic, with latency inducing plugins on an aux or output, using Low Latency mode or direct monitoring via his audio interface will have zero effect on recording alignment. The recording has already happened before those plugins and the output buffer do their thing.

 

But he'll obviously get lower monitoring latency.

 

PDC latency affects monitoring latency for both monitoring scenarios. But, PDC only affects recording alignment for direct/mixer monitored external sound sources. That's because Logic doesn't subtract the PDC latency when applying recording latency compensation, which is very easy to do.

 

So, the only reason to use Low Latency mode when software monitoring is to reduce monitoring latency. It'll have no effect on your software monitored recordings.

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As you can see on the images I have uploaded this is how I'm setup. I have also one of my soundcard which has a level for monitor and for computer. Is that what you are talking about when you say monitoring?

 

Let's take your Triton as an example. Ignore recording for a sec, and just think about monitoring:

 

How is the audio from the Triton routed to your monitors?

 

Direct/Mixer Monitoring (Hardware Monitoring)

 

Is the Triton going into an external mixer and then straight to your speakers? This is mixer monitoring (a type of hardware monitoring).

 

Or, is the Triton going into your audio interface, but instead of monitoring through Logic, you use the DSP mixer on your audio interface to send the audio straight back out to your speakers. This is direct monitoring via your audio interface (the other type of hardware monitoring).

 

 

Software Monitoring

 

OR, is the Triton going into your audio interface, then into Logic, through the External Instrument plugin, through other plugins in Logic, and then Logic sends the audio to your speakers. This is software monitoring.

 

 

As far as I'm concerned, "HOW ARE YOU MONITORING YOUR EXTERNAL SOUND SOURCE" or "WHAT ROUTE DOES YOUR EXTERNAL SOUND SOURCE TAKE TO REACH YOUR MONITORS" is the single most important piece of latency information for diagnosing latency problems with external synths and sound sources. Nobody ever asks the question when replying to these latency threads, so I end up sounding like a stuck record!

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If he's software monitoring through Logic, with latency inducing plugins on an aux or output, using Low Latency mode or direct monitoring via his audio interface will have zero effect on recording alignment. The recording has already happened before those plugins and the output buffer do their thing.

 

Here's a screen shot of me snapping my fingers to the metronome.

I have Induced 1000 ms of latency at the output, to keep this simple at a tempo of 120 BPM.

I did three passes. One with Software Monitoring turned OFF, one with Software Monitoring & Low Latency Mode ON, and one without Low Latency Mode.

 

511793191_RecordingthroughPlug-inLatency.png.9caee176d48b69d092f64e0e3cd09834.png

 

It's pretty obvious that the last recording, the one through Software monitoring without Low Latency Mode, is 2 beats or 1000 ms late.

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How are you recording when software monitoring?

 

Straight from an input?

 

Or via a Bus?

 

Did you also check that your finger clicking alignment at your outputs - to do this you'll also need to record your outputs with a click coming from Logic's grid?

 

I'll see if I can demonstrate what I'm talking about..

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The audio output from my triton is going into the input of the soundcard and then I created an external midi track with no effects on it in Logic. Also the midi from my triton is going out and into a midi interface and then ends up in my laptop via usb. As you see in the image of my soundcard the INPUT button is turned down all the way. So I'm montoring through Logic only.
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The audio output from my triton is going into the input of the soundcard and then I created an external midi track with no effects on it in Logic. Also the midi from my triton is going out and into a midi interface and then ends up in my laptop via usb. As you see in the image of my soundcard the INPUT button is turned down all the way. So I'm montoring through Logic only.

 

 

OK, this is going to take some time, so I'll give you a short answer for now.

 

Send the Triton's External Instrument track (track 4) to a spare Bus, not the stereo output.

 

Then set the input of track 4 (Korg REC) to that Bus (not Inputs 11-12). Make sure software monitoring is enabled. Then click the 'I' button to enable input monitoring.

 

The reason? When software monitoring you don't want recording latency compensation (RLC) switched on. Recording from/via a Bus switches off for RLC that track. RLC is for direct/mixer monitoring, not for software monitoring. Recording direct from an input, whilst software monitoring, is the reason for this:

 

Another problem I'm having is when I record midi from an external source there is no latency during the actual recording but when you try to playback and listen to what you recorded there is so much latency that it is completely off beat.

 

It's a classic complaint: "My synth sounded during MIDI playback and/or during recording, but when I record the synth's audio and play back that recording I get latency problems".

 

Logic is incorrectly applying RLC to your software monitored recordings, and moving your recordings a roundtrip earlier on the grid.

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No audio? Is the input(s) from your synth selected in the External Instrument plugin?

 

 

Actually, I've just come across some hideous bug in X doing it that way. If I have the synth's recording track Input monitoring enabled, I get weird latency whilst monitoring, even though the subsequent recording is still in on the grid. But if I record enable the track (with or without input monitoring) then everything's in time again. Never noticed it happening in v9 or an earlier version of X, so needs more investigating. I'm not using my usual (complex) template, just a new blank project, so not sure what's different??..

 

 

 

In the meantime it works fine with an (input) Aux. So, create an aux in the mixer, set the input of the aux to those coming from your synth, set the aux's output to Bus 5, and leave the recording track's input as Bus 5. On the external instrument track, just output to the stereo output as you were before, and set the external instrument plugin's audio input to the same inputs going into the input Aux. So, you monitor through the external instrument track, and record through the 'aux > recording' track.

 

EDIT: And you'll have to mute the recording track whilst monitoring etc., or switch off input monitoring for that track.

 

 

I'll upload a simple v9 template project asap for you to have a look at. Was working in X before I realised you're using v9. :roll:

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OK, here's a simple Logic 9 project with the setup I described for software monitoring, now using an Aux as an input, rather than sending to a Bus from the External Instrument track.

 

Don't enable input monitoring on the recording track (track 2 in the screenshot), as the external instrument track is handling monitoring. I've used mono channels here so you'll probably have to change those.

 

Also, note the negative region delay highlighted by the red box in the inspector. I'd be slightly surprised if you don't also need a negative delay - just decrease it until it sounds in sync with a click, drums or backing track coming from Logic, and set the negative delay before adding any latency inducing plugins on an aux or output to make your life easier.

 

This setup was configured for an ESI-32 sampler:

 

SM-PDC.thumb.png.80a4199a003006b4dd1d55b437ac9477.png

Software Monitoring & PDC.zip

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I actually tried the old first setup I had but using your idea with the "delay" for the playback. And it actually helped. But when you then record it to audio there are some milliseconds delay difference but not that noticable. No matter what this is really a huge bug if you can even call it that. It shouldn't be like this. There must be a way. I mean what on earth did all the old school pro's do back when we didn't have software instruments but only analog synths? I mean I have a hard time believing they did an entire Michael Jackson album going through so much trouble with every single track.
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If he's software monitoring through Logic, with latency inducing plugins on an aux or output, using Low Latency mode or direct monitoring via his audio interface will have zero effect on recording alignment. The recording has already happened before those plugins and the output buffer do their thing.

 

Here's a screen shot of me snapping my fingers to the metronome.

I have Induced 1000 ms of latency at the output, to keep this simple at a tempo of 120 BPM.

 

I did three passes. One with Software Monitoring turned OFF, one with Software Monitoring & Low Latency Mode ON, and one without Low Latency Mode.

 

1725362138_Recording20through20Plug-in20Latency.png.229f56bc3805ae33ce2713ae49bca84e.png

Edited by RedBaron
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But when you then record it to audio there are some milliseconds delay difference but not that noticable.

 

Probably jitter. All hardware synths have some response time jitter.

 

 

No matter what this is really a huge bug if you can even call it that. It shouldn't be like this. There must be a way.

 

Bug might be too strong a word. But it definitely doesn't need to be this way.

 

All Apple has to do is switch off Recording Latency Compensation for any tracks that have the Input monitoring button enabled. It's that simple as far a the audio config is concerned.

 

But you'll still have MIDI transport jitter + synth response time jitter (combined jitter). And you'll still have to set the track delay yourself, every time you change buffer size or sample rate. Simplest & quickest way is to play a 100% quantised 16th note (pulse) sequence from your DAW whilst playing the same 16th note sequence whilst adjusting the track delay. Otherwise, you'll have to resort to looking at the timing in a sample editor, and this can be tedious. It's much easier to do it by ear though.

 

Also, once you've set a track delay for a synth, note down the buffer size, sample rate and the track delay. Then you can just punch that number in the next time you use that buffer size & sample rate combination.

 

 

I mean what on earth did all the old school pro's do back when we didn't have software instruments but only analog synths? I mean I have a hard time believing they did an entire Michael Jackson album going through so much trouble with every single track.

 

In my case, Atari ST triggering synths which were plugged into a mixer, straight to DAT. Not that I'm calling myself a pro. :mrgreen:

 

It was much simpler really. But I can still remember trouble shooting MIDI timing problems. It wasn't perfect. Just listen to Donna Summer's 'I Feel Love'. Some of the drum timing is awful. But that's going even further back...

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OK, I'm going to have to break this up into two posts.

 

Software Monitoring & Recording Alignment

 

Before I deal with the PDC + software monitoring issue, I thought I'd illustrate why you should record through/from a Bus when software monitoring. So this test doesn't have any aux/output PDC latency.

 

I'm sending 16th clicks via analogue loopback (out 3 > in 5), and using an Expert Sleepers Latency Fixer plugin to send the clicks a roundtrip early. This gives me precise control over the timing of the looped-back clicks. Logic doesn't know that it actually sent the clicks, it's just recording an audio stream from an input. My roundtrip latency is 518 samples (10.79ms). At 120 BPM & 48k, a click occurs every 6000th sample.

 

The loopback click is then software monitored from input 5 (or bus 2) to my outputs. At the same time, I'm sending an identical click straight to my outputs ('Grid Click'). I've made two separate recordings. One is recorded direct from an input. The other is recorded via an aux/bus. Whilst recording the software monitored clicks in Logic, my main stereo outputs are also recorded using Audio Hijack - the 'Grid Click' is panned left, and the software monitored click is panned right:

 

SM-Input_Config.thumb.png.9c7449d396f9c3e73123124afd7244db.png

 

Here's what I recorded at my outputs as I was simultaneously recording the loopback click. As you can see, the top 'Grid Click' is perfectly aligned at my outputs with the bottom loopback click, for both the input recording and the bus recording. In other words, monitoring is perfectly aligned for both recordings:

 

973095157_SoftwareMonitoredClickfromInput(atOutputs).png.3e033108d4577933bafe525c9fb829f4.png

1568398771_SoftwareMonitoredClickfromBus(atOutputs).png.4cc408aa33892851dfc687192909793e.png

 

However, when you look at the two recordings in Logic, you can clearly see that the click recorded direct from the input is a roundtrip early (-518 samples), whilst the click recorded from the aux/bus is perfectly aligned with the original (source) click that was sent round the loopback:

 

204278428_SoftwareMonitoredClickfromInput.png.cd5fec8ff96e05727bd189692e3ffb00.png

1809229133_SoftwareMonitoredClickfromBus.png.064c2210d3a19c94a5ce3931e924bbb1.png

 

The reason?

 

By recording direct from an input, Logic applies Recording Latency Compensation (RLC). RLC has moved the new recording to a position that is a roundtrip earlier on the grid. The recorded click is a roundtrip too early, or misaligned by a roundtrip. If you increase your roundtrip latency, your recordings will be even earlier.

 

But, by recording from a Bus, RLC is switched off for that track. RLC is not required for software monitored recordings, because the latency compensation is handled by sending/playing the audio early, ahead of the grid. RLC is only required for direct/mixer monitored recordings. Also, when you play back the Bus recording, you'll be hearing exactly what you heard during recording.

 

Here's what the two recordings sound like when played back at the same time as the 'Grid Click', both now panned centrally:

 

Input recording playback, mixed with original (source) click.wav

(a roundtrip early, misaligned, flamming)

 

Bus recording playback, mixed with original (source) click.wav

(sample accurate recording alignment)

 

 

And finally, here's the Logic X project, which includes all recordings except the two above:

 

Software Monitoring and Recording Alignment.zip

------------

 

Hope this clears a few things up! I'll post about the PDC + software monitoring *issue* soon..

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