I'd like to share a great studio technique that I call the "echo demo". I hope you find it as useful as I have.
How do you determine optimum mike placement? By ear, of course, but how do you hear just the recorded sound without any live sound? The big-budget answer: have your assistant fiddle with the mike out in the tracking room while you listen in the control room. Well, I ain't got no assistant. I ain't got no control room. All I got is a one-room home studio with a PC and a DAW.
So, here's what I do: I set up my DAW to send the incoming audio from the mike directly out through the monitors, without actually recording it. (In Protools, this involves pushing the track's record button, and disabling low-latency monitoring in the operations menu.) In other words, I use my DAW like a PA.
I want to emphasize the need for caution at this point. BE CAREFUL!!! Studio mikes are very sensitive and often prone to feedback. Never put the mike close to the monitors, or point it right at them. Use a gobo, if you have one. I recommend first turning the monitor volume all the way down, then setting eveything up, then finally slowly turning up the monitors.
Next I put a long delay plug-in on the master track and set it for 3-4 seconds. Now the fun begins. I hold the mike up to the instrument (or amp) and have the musician play a short test riff (perhaps an arpeggio). Then we listen to the riff echo in the monitors. I move the mike around and he/she plays the exact same riff, and we listen again. Over & over until we zero in on the best possible sound. Notice I said "we". A big advantage the echo demo has over the control-room method is that the musician can offer his feedback, too.
The preceeding example is for a melody instrument like a sax. For brief percussion sounds, say a cowbell, using a shorter delay greatly speeds up the process.
Now, there's just one little problem. A sensitive mike will pick up the monitor echo and send it off to the DAW, to be sent out through the monitors again as a second, fainter echo. These secondary echoes can be confusing and annoying. There's three ways to get rid of them:
1. Use headphones.
2. If by chance you have a mike muting footswitch (called a "cough drop" or a "short stop"), just mute the mike during the echo.
3. The best solution: use a gate. Put it on the master track, right before your delay plug-in. Set the threshhold low enough for the test riff to get through, but high enough to keep out the monitor echo. Set your attack as fast as possible, so you don't chop off the instrument's attack. Give yourself lots of hold and decay. Set them long enough so you don't chop off the end of the riff, but short enough so that the gate shuts down before the echo comes back. For a 2-second test riff through a 3-second delay, try setting each to a half-second. Ideally, use a gate with a sidechain, and send a slightly-less-delayed signal to the side chain, so that the gate opens up a bit before the note.
You can demo multiple-mike setups this way, too. Just set up your DAW to output all the mikes. The one gate and one delay will handle everything, though you may have to adjust the gate threshhold and/or the monitor volume. With the plug-ins on the master track, I think of it as gating/delaying the speakers, not the mikes.
Here's a fun idea for rhythm instruments. Set the delay to correspond to a common tempo, say 2 seconds for one bar of 120 bpm. Get the musician to alternate playing a bar and listening for a bar. He can often fall into a groove and "jam with himself". You may need to use a shorter decay on the gate. You can also double the delay (use a second plug-in if you have to) and play/listen for two bars. This transforms a tedious process into something fun and helps keep your clients fresh for recording.
Okay, now that you've determined how best to place a given mike for a given instrument, how do you choose which mike to use? You demo them, of course, but how do you listen back? The usual way is to record the musician with several mikes at once, then loop the recorded results, using the solo buttons to switch back and forth between samples. Workable, but cumbersome.
Let's use echo-demoing: First, set up your DAW so that each mike has its own track, output directly to the monitors as before. Then put a gate and a delay on the master track, as before. Then put another delay on the second mike track, two delays on the third, three on the fourth, etc. Now each mike has its own unique delay time. Play a riff, and you will hear a series of echoes, one for each mike. This allows you to instantly evaluate your mikes. You can even tweak the mike placement further at this point. Be sure to play both high and low riffs, to test the full range of the instrument.
One more application: demoing effects. To do this, set up as for demoing mike placement, and add a send to an aux track. Put your effect on the aux track, along with another delay. Now when you play a riff, you'll hear a raw echo followed by a processed echo. If you want to compare different settings, set up several aux tracks, each with its own effects chain. Put one delay on the second, two on the third, etc. Remember to mute the raw signal. Now you'll hear a series of echoes, each one processed differently. This is especially useful for experimenting with the order of plug-ins.
Echo-demoing really excels in situations where the musician is also the recording engineer. A musician with a home studio can learn a lot about recording himself. It also works for experimenting with effects used for his live sound. But what if you are in a full studio and you want to take advantage of the speed and directness of echo-demoing? You have two choices: put the musician and the mike(s) in the control room, or put your monitors in the tracking room. Which way you go depends on the particulars of your set-up.
These are just some of the uses of this method. It's a great way to explore the potential of your studio. Any time you want to experiment with different options and quickly evaluate the results, consider the echo demo.