I've recorded a couple of songs with just three tracks: acoustic guitar, bass and lead vocal. I'll obviously pan both bass and lead vocals in the centre. I'll probably have to centre the acoustic guitar too, since if I pan it a little to one side there'd be nothing on the other side to balance it volume‑wise. There wouldn't then be much of a stereo image, so I figured that a stereo reverb might give the song a sense of space. If I use something like a Lexicon MPX550, how would I route the effect? Obviously, the vocal is mono and sits on one track. The effect return part is easy: effect return to 1 and 2 and pan them hard right and left. But what about the effect send? The Lexicon has 'R' and 'L' inputs, so would I use two effect sends for the vocal, panned right and left?
Jay Menon
SOS Technical Editor Hugh Robjohns replies: The vast majority of artificial reverbs are actually mono in, stereo out devices — and if they have a stereo input, this is usually summed to mono internally before the reverb signal is generated. There are a few devices that have genuine stereo inputs and create early reflection and reverb patterns according to the relative levels of left and right input signals, but these are usually only the high‑end hardware units and the more sophisticated plug‑ins.
The notion of keeping bass in the middle is seated in the days of vinyl records, and isn't a constraint of modern digital media at all. If you need lots of bass power in your track, then keeping bass instruments central makes sense, as both speakers are working hard for you, but in something as simple and gentle as this kind of track, panning the bass partially to one side would be acceptable and would make more sense from a spatial point of view.
Imagine the performers on stage: I'd probably pan the bass a quarter to a half left, the guitar a similar amount to the right, and the vocal in the centre.
If I was using a conventional summed‑input reverb, I'd probably just feed in the appropriate amounts of all three instruments and let the stereo return occupy the full width, to put some space around the instruments. With a true-stereo-input reverb I'd feed in the panned stereo signal. Alternatively, you could mess around with slightly different stereo reverbs panned to complement the instruments as suggested above, but in my experience this can often create a confusing mush of reverb. Keeping it simple is usually the best way.