Best way to determine what my I/O buffer amt should be when recording vox?

I/O Buffer size will not improve the quality of a recorded audio file. It may improve your timing in the recorded audio file!

open a project setup like you'd normally use to record into place the track in ready mode and play or record and monitor the results. What's the latency like? Find a setting that is comfortable.

JG

The larger the buffer, the lesser load on your cpu and the greater latency of sounds listened to through Logic. When vocal tracking, one usually monitors directly through the interface for zero latency. As such, the buffer setting can be large with no problem. When tracking THROUGH logic, like when playing MIDI or software instruments or when recording a guitar while listening to the pedal board fx, the buffer must be low enough that you can play with accurate timing. I find that 128 is small enough for guitar and MIDI.

eMagnus wrote:
So the only thing the I/O buffer size effects is LATENCY correct?

Once I was bouncing midi to audio on a track that had a 3rd party plug-in. I kept getting clicks in the audio file. Everyone thought the issue was with the buffer size. Did they have any reason to suggest this?

Yes.

You can only empty and fill a water bucket so fast, the smaller the bucket the more times you have to fill/empty it. (the plus being it takes less time to do so, the downside is, it's more work.)

Think of the empty/fill cycle as your latency.

Something to consider... needing a low buffer is worthwhile for (mainly) two things.

Reasonable reaction time when playing a softsynth, -and- realtime monitoring of an audio signal through Logic's audio engine.

If you monitor out side of Logic you can raise the I/O buffer to 256, 512 or 1024 and give your computer a rest. I usually monitor via the interface's direct monitoring function and run that through a mixer with a hardware reverb unit. Generally leave my I/O buffer high so I don't have to worry about the many pitfalls of low latency monitoring.

pancenter-

p.s. Softsynth monitoring takes less time than monitoring an external audio signal. While monitoring a vocal with effects may need a buffer of 64 to be close to realtime, a softsynth can achieve close to the same latency using a buffer of 128.

p.s.#2 It's OK, or even a good idea to raise the I/O buffer when bouncing effect heavy tracks, or an effect heavy mix.

eMagnus wrote:
So the only thing the I/O buffer size effects is LATENCY correct?

Once I was bouncing midi to audio on a track that had a 3rd party plug-in. I kept getting clicks in the audio file. Everyone thought the issue was with the buffer size. Did they have any reason to suggest this?

There is another possibility related to Logic and some third party plugins.. sometimes a click and/or static can be introduced a few seconds before the plugin activates, if said track contains automation the chances are even higher. As mentioned before, raising the I/O buffer before bouncing is never a bad idea. I only lower the buffer if I need to play a softsynth, or absolutely need to monitor through Logic's audio engine otherwise the buffer stays at 256 (or higher).

You don't need to run at a 32 or 64 I/O buffer just because you can nor do you need to record at 192kHz because you can.

pancenter-