Logic has a handy function you can use when recording musicians live (without an external desk) , for monitoring ininputs such as synths or for mastering when external processing is used.
Another feature is the ability to use effect plug-in's live.. eg. "Can I hear my vocal with a bit of reverb and delay" (The vocal is recorded dry but the artist hears reverb or whatever plug in is applied to the channel or send bus)
This option can be found in 'Preferences' - 'Audio'
Software monitoring is used, or not, generally when recording.
If you want to hear a synth or guitar live all the time (not in record mode), create an auxiliery input for that.
Recording without an external desk
When the option above is 'ticked', the tracks you have enabled to record will allow you to hear the sound through them.
On audio cards and interfaces, if you have 2 in and 2 out, then this is the only way you can hear back live as you play and it is likely you would use the headphone output on your audio interface if isolation was required (mic'ing amps, percussion etc).
If your audio card/interface allows you different outputs, you could create headphone mixes for individual musicians. This is done by selecting a bus, say for a drummer and you are monitoring live as they play (software monitoring ticked). You can adjust the amount of snare, click, kick etc sent to this first bus (let's call it bus 1), to suit the musicians monitor or headphones. If they wanted some guitar in their mix, you'd send the guitar to this bus 1 too, again to suit just this drummers mix.
Next, the guitarists mix. Maybe they just want click, snare and and some guitar?. So now you create another bus send, go back to the drums, just add this bus 2 to the snare track, then turn that up into the guitarists mix, same again for the click.
These sub mixes you are creating will need to then go out of your audio interface channels and into a headphone amp that has more than one input and separate headphone outputs.
At Metech we use the PreSonus HP60 (pic below) 6 Channel headphone amp.
For each headphone channel, we can send three stereo audio streams.. For instance, a defined mix, then an individual instrument, or 2 etc, etc.. and a click, into different inputs, this allows fine pan positioning and levels to suit the musician.
Recording with an external desk
The way we run our system here is with an Audient Zen console, which gives us the facility of routing headphone mixes through the desk to various Auxiliary outs, in addition to individual out's, straight to the headphone mixes in the PreSonus. While working in this way, we don't have software monitoring ticked, as we are hearing our control room mix through the stereo outs of Logic into the Zen desk, alongside the set to 'post' faders, which won't change levels to the recording inputs if moved but can be adjusted for control room listening. We can solo, adjust playback volume and alter sub headphone mixes without effecting or interupting the recording process and set levels.
Mastering and Software Monitoring
If you are going to use external analogue equipment such as eq or compression it's handy to have software monitoring on. You'd send your mix that's been previously bounced to a stereo file (but still at the full resolution you recorded at eg. 24 bit at 96k) bounced and sitting on the Logic timeline out of say channels 17 and 18 (making a stereo pair). This audio would then pass through your analogue compressor or eq and come back straight into the audio interface. You would control the input to these devices from the corresponding Logic output.
Enabling a track in Logic for recording and feeding your returns into say inputs 3 and 4, you would then set that track's outputs to stereo (usually out's 1 and 2) and hear that back. Providing your card is decent, this will be what you are going to record, or as close as achieved by your analogue to digital conversion. Software plug-ins such as eq, an ad-limiter, Limiter on your Logic stereo out's will then make the monitoring even closer to the finished master.
It helps running this all live, as you can adjust your external hardware until the point you are ready to commit to recording that stage of the mastering into your machine. It is of course possible to run analogue and software processors simaltaniously, and often this is done to great effect.
More information about mastering in (and around) Logic Pro here.
Cian Houchin, Metech Multimedia Ltd