In the 07/02/04 edition of inSync we talked about how to make a live reverb chamber to add spice to your guitar recording. In this installment, we’re going to continue along those lines and discuss a means of not just adding room size, but increasing the size of the room sound without moving into a larger space.
To increase the size of the room, the trick is to place the cabinet at one end of the room facing the opposite wall and place the mic a few feet away. However, instead of facing the mic at the cabinet, point it away from the amp, towards the opposite wall as well. Use a mic that has a cardioid or supercardioid pattern. If you recall from last time, cardioid mics reject sound coming from behind them, which is desirable, since the reflected sound is what we want. The mic rejects the direct sound coming from the amp, but “hears” the reflected sound coming off the wall. This increases the delay of the initial refection and makes the room sound larger. Experiment with mic placement in order to overcome the effects of comb filtering as well as room size.
It is optimal for mixing purposes to record the room mic (or mics) on to separate tracks. This enables you to choose the right blend of direct and reflected sound during the final mix. If you don’t have the extra tracks to spare, and must print the close mic and the room mic(s) together, then remember to be conservative with the amount of room sound that you include. Recall from earlier guitar-recording tech tips that too much reverb can cause a guitar track to sound too distant in the mix. This is also true if you include too much room sound. Besides, you can always add a little reverb from an effects processor if the guitar sound needs a little more depth. The reverse is not so easy.