Chasing low latency in Logic Pro X

[Jean-Luc Pickguard]

I have been recording a new project with my Mac Mini M2 pro 32GB running Ventura with Logic Pro X.

 

I had an aggregate device configured consisting of my Fender Mustang GTX100 amp along with my focusrite scarlett solo gen2.

 

I was getting an annoying amount of latency when recording my new Strat into logic using the usb interface of the GTX100 amp.

 

I thought maybe the aggregate device was causing the latency - I had to monitor the guitar from the amp's own speaker as I coul dhear the latency when using the input monitor on the channel, but even then the resultant recording was audibly out of sync with the existing tracks - it was lagging by something between an 1/8 or 1/4 note.

 

My plan was to abandon using the USB of the amp and instead take a stereo output from the XLRs on the back of the amp.

 

To be able to do this I ordered a twin XLR cable (colour coded black & red for left and right) and a focusrite scarlett 2i2 gen3 (studiospares has them at a very good price at the moment)

 

I tried recording using this setup with just the scarlett 2i2 interface selected in logic and I still had the same latency issue. This was very disappointing.

 

Studying the focusrite website I found this article: https://support.focusrite.com/hc/en-gb/articles/208736249-How-can-I-improve-latency-using-my-2nd-3rd-Gen-Scarlett-Clarett-USB-interfaces-on-Mac

which has a link to something called the 'Focusrite Low Latency installer' so I installed it.

 

I also found this page on Apple's website: https://support.apple.com/en-us/HT207527

This has details of the 'Low Latency Monitoring Mode' which uses a button to disable hungry plugins such as the Adaptive Limiter. This plugin was probably causing the issue due to its lookahead feature.

 

I selected the option to add a button to enable Low Latency Monitoring Mode so it could be selected whenever I record a track - shown below in orange.

 

 

I have set up a new aggregate interface consisting of the Scarlett 2i2 and the USB interface of the GTX100 amp and when recording from the amp's USB interface I now can turn the master volume of the amp down and use input monitoring to hear the guitar through my headphones/desktop monitors along with the existing recording with no discernable latency. RESULT!

 

I checked the latency as reported in Logic's audio settings and was surprised to see how low it actually is.

 

 

I could have got away with not upgrading my interface and I didn't have to use the twin XLR cable, but I should be able to sell the scarlett solo to recoup some of the outlay and having two mic inputs is bound to come in handy at some point.

 

How much latency do you have with your gear?

Can you use input monitoring on the channel or do you need to use a direct monitor on the interface etc when recording?

 

 

[sammybee]

You're doing better than me for Latency! (M1 MB Air 8gb). I monitor through my interface. I DI everything and record dry then add amp modelling and fx to taste once I'm happy with the take(s).

 

[lurksalot]

My ‘latency’ is bizarre !

when I play along to a track, I monitor through the computer back to the interface so that any FX are sent back with the signal . 
it always sounds pretty tight.

when I listen back , the recorded track is always early and needs retarding slightly.

I guess there is a setting that auto adjusts the latency that overdoes it.

this is reaper as it happens though ! 

[Jean-Luc Pickguard]

Although I'm afraid I don't have any experience with reaper, it is interesting that the issue you have described is pretty much the same as I experienced with Logic Pro X before I found a solution. Based on what I now know about Logic I'm wondering whether your issue has an equivalent cause, ie plugin(s) on existing tracks when you're recording a new one. With logic it seemed to be specifically a limiter plugin that had a lookahead element which caused the new recording to be offset from the existing tracks by a fraction of a second.

[BigRedX]

I've found the only fool-proof way to avoid latency is not use software monitoring, but to monitor via a mixer.

[lurksalot]

2 hours ago, Jean-Luc Pickguard said:

Although I'm afraid I don't have any experience with reaper, it is interesting that the issue you have described is pretty much the same as I experienced with Logic Pro X before I found a solution. Based on what I now know about Logic I'm wondering whether your issue has an equivalent cause, ie plugin(s) on existing tracks when you're recording a new one. With logic it seemed to be specifically a limiter plugin that had a lookahead element which caused the new recording to be offset from the existing tracks by a fraction of a second.

Could be , but I don’t really understand the intricacies of the software , especially the vagaries of the interaction between plugins, Reaper and of course, other plugins.

I just make sure to remember that I might need to reset a track occasionally and not beat myself up because my playing is ahead of the beat, because it isn’t 😁

[lurksalot]

57 minutes ago, BigRedX said:

I've found the only fool-proof way to avoid latency is not use software monitoring, but to monitor via a mixer.

My monitoring always seems spot on , just the recording seems advanced like I was playing ahead of the beat. I suspect a latency correction somewhere that over compensates.

I reckon that I might find it somewhere , but in my small scale , simplistic approach , the workaround doesn’t stress me out too much 😁

[basexperience]

I'm using a Scarlett 18i20 3rd Gen with a2017 intel iMac core i7, 40GB memory and Monterey. Logic is reporting 36.ms round rip, 1.8ms output - I haven't done anything about low latency tweaking apart from selecting 32 samples as the buffer size. Drivers are the defaults.

 

I don't tend to monitor through headphones, although I did do some recording direct into the interface the other day, so it's interesting to read up on tweaks like this. It seemed pretty usable!