Yes.

That was simple.
Mx. Remy Ann David

Welcome to RO. Ask a very vague question get a vague answer.
You need to ask questions that provide enough information to recieve intelligent answers. This type of question would probably have been best posted in the newbie section, where you might recieve more answers.
Live /Acoustic? Like a string quartet? Bluegrass band? Acoustic/Electric rock? How many musicians, playing what instruments? Are you looking to just get a stereo track of the performance or multi track for later editing/processing? Do you have a budget? Do have a PA? Are you micing individual instruments presently? If so with which mics? And so on and so on. Give us some clues.

im definitely a newbie. its an acoustic guitar trio (well one acoustic bass). so those three instruments would be plugged in hopefully straight to the mixer. 2 microphones for vocals. i have a 24 channel mixer and a power amp. do the guitars and mics need some sort of pre amp for live playing and recording? what about a compressor? we dont use many effects. maybe some chorus or reverb. i want to use the rack for playing live but also to use at home for recording into a computer with pro tools. so anything else i would need for recording. hopefully this is a little better.

thetrakis wrote: im definitely a newbie. its an acoustic guitar trio (well one acoustic bass). so those three instruments would be plugged in hopefully straight to the mixer. 2 microphones for vocals. i have a 24 channel mixer and a power amp. do the guitars and mics need some sort of pre amp for live playing and recording? what about a compressor? we dont use many effects. maybe some chorus or reverb. i want to use the rack for playing live but also to use at home for recording into a computer with pro tools. so anything else i would need for recording. hopefully this is a little better.

Let's take the home recording case first. You talk as though you propose to record all three of you playing at once, rather than tracking it an instrument or voice at a time.

Once you utter the words "Pro Tools", you are cornered, and forced into buying a Digidesign interface (for PTLE) or an M-Audio interface of some sort (for PT M-powered). Both of these entry-level versions of PT are restricted to 18 concurrent tracks when recording. With the larger Digi or M-A interfaces, this can be filled by 8 analog (XLR + TRS), 8-channel ADAT (digital) and 2-channel S/PDIF (digital).

Depending on your mixer (what is it?), you will likely be able to take 8 analog direct channel outputs, either from direct outs or via the channel inserts. You need to sit down and work out how you will use those 8 available channels. Two for vocals are easy. For each of the acoustic guitars, you really need at least one microphone and one DI channel. The bass can be DI only. You are already up to 9 channels before you add any room or ambient mics.

The other point about mixers is that they seldom have the correct high-impedance inputs for plugging a guitar pickup directly into. This applies as much to the live performance case as for recording. You may need to get 3 DI boxes for the 3 instruments, and then use XLR inputs for these.

A compressor used purely as a limiter on the FOH main loudspeakers is OK, but you will run into a bagfull of trouble trying to compress vocals live, as feedback will come up and bite you.

I haven't really started on what else you would need for recording your trio at home. Acoustic isolation screens (gobos), room treatment, headphones with amplifiers are all needed in addition to good instrument microphones and monitoring loudspeakers.

What it comes down to is that you really need completely separate rigs for live performing and home recording. A mixer with power amps and speakers is fine for live work, but it's out of place in a PT recording setup, where you need a computer interface, studio-quality mics and nearfield monitors. It's possible to share outboard effect units, but PT does not make it easy to use external analog effects.

Good luck!