I am wanting to use the amp and cabinet simulations in Logic ProX to record DI'ed guitars in real time, so that the guitarist hears the simulations as he plays.
Logic Pro X, OS X Mavericks (10.9)
The only potential issue here is latency - how much can you/he tolerate?
For example, the recording path would look something like this:
Gtr -> Interface -> Computer -> Logic -> Amp-Sim
It also has to make the return path:
Amp-Sim-> Logic -> Computer -> Interface -> Speakers
This whole round trip is called 'latency', and it's usually measured in milliseconds, depending on how fast your interface is, and how small your audio buffer is. For example again: A thunderbolt interface is so fast, latency may be unnoticeable. On the other hand, a USB 2.0 interface may have considerably more latency.
How much latency is too much? Any time the latency affects the performance (i.e. hearing your guitar/vocal late), it's too much. Normally a few milliseconds is fine for most folks. Others will disagree (speed metal players?)
The 'solution' to the problem is direct monitoring. This basically happens inside your interface, and allows you to listen to a copy of an input on an output (like phones or speakers), without making the long trip:
-> Computer -> Logic -> Amp-Sim -> Logic -> Computer -> Interface -> Speakers
instead a 'direct monitor' configuration looks like this:
GTR -> Interface -> Phones/Speakers
The plus of direct monitoring? (nearly) no latency. The downside? It doesn't pass through your computer/DAW/Plug-In at all.
The only potential issue here is latency - how much can you/he tolerate?
For example, the recording path would look something like this:
Gtr -> Interface -> Computer -> Logic -> Amp-Sim
It also has to make the return path:
Amp-Sim-> Logic -> Computer -> Interface -> Speakers
This whole round trip is called 'latency', and it's usually measured in milliseconds, depending on how fast your interface is, and how small your audio buffer is. For example again: A thunderbolt interface is so fast, latency may be unnoticeable. On the other hand, a USB 2.0 interface may have considerably more latency.
How much latency is too much? Any time the latency affects the performance (i.e. hearing your guitar/vocal late), it's too much. Normally a few milliseconds is fine for most folks. Others will disagree (speed metal players?)
The 'solution' to the problem is direct monitoring. This basically happens inside your interface, and allows you to listen to a copy of an input on an output (like phones or speakers), without making the long trip:
-> Computer -> Logic -> Amp-Sim -> Logic -> Computer -> Interface -> Speakers
instead a 'direct monitor' configuration looks like this:
GTR -> Interface -> Phones/Speakers
The plus of direct monitoring? (nearly) no latency. The downside? It doesn't pass through your computer/DAW/Plug-In at all.
Unfortunately using an interface's 'direct monitoring' (where the terminology varies with the product) would cut out his amp/cab sim as well.
Direct monitoring would only allow him to hear his DI (unamplified) guitar, right?
Thanks Pete,
I am actually a retired professional audio engineer of more than 40 years standing so I get latency and the signal path. I just did not know what to switch on or off in Logic to achieve real time monitoring of the simulated guitar sound.
Another post sorted me out and I now have near zero latency monitoring of the effected DI input in real time.
Thanks for your contribution though, much appreciated, and it will explain the situation well to any novices out there in the world of Logic recording.
Turn on Software monitoring in Logic and turn off the direct monitoring from your interface.
Thanks.
Works perfectly now that I have followed your instructions.
Cheers
That's great news.
It's pretty awesome to be able to change cabinets and amps on the fly. 🙂
How do I use the amp and cabinet simulations in Logic in real time?
