Troubleshooting the Vocal Chain Of Command
Finding and Rooting Out Distortion on Vocals
| By CUS and AMIR SAID (SA’ID) |
When it comes to recording and mixing vocals, there’s one question that often comes up: ‘What do you do when a vocal starts to peak and distortion is on the horizon?’ In many cases, all one needs to do is turn down the level of the mic (mic signal) to tape. But this isn’t always the actual cause of the distortion. In fact, the “fix” (solution) can depend on any number of circumstances. However, finding out the root of vocal distortion usually comes down to some problem in the signal chain of the microphone.
When you get to the mix stage and a vocal is distorted, troubleshooting the distortion requires that you trace the points of the mic’s signal chain to the tape source (these days, usually a software recording program like Pro Tools, Logic, etc.). Typically, the points of a mic signal chain break down like this: (1) mic patched into an external pre-amp; (2) pre-amp patched to compressor; (3) compressor patched into the tape source. (In some cases, a mic is patched into a mixing console, then an external pre-amp.) If there is distortion at the tape source, it doesn’t mean that was the starting point for the distortion. Signal overload is usually the culprit in these instances, because a record level may be fine and can still be distorted. Therefore, you must troubleshoot backwards through the mic’s signal chain to find the cause of the distortion.
Start off by examining the first “patch-point” of the mic, prior to the tape source; this may be either your mixing console or your pre-amp. If you’re using a mixing console, you’re monitoring the channel that the mic is patched into; so make sure that the signal is not peaking at the meters. If not, then you know that you can pull the fader down some in order to feed less signal to the tape source. However, if at this point, the distortion is undefined, you have to continue “reviewing” the patch-points of the mic’s signal chain.
Adjustments of distortion are usually made at the compressor. Typically, it’s a case of the vocal not being compressed enough, which means the threshold on the compressor would need to be pulled back some. If the compression setting seems to be fine, yet still overloaded, you have to examine the next patch-point that supercedes in the vocal chain, which is the mic pre amplifier.
Some pre amps may have a meter alerting you of how much signal is coming into it by a vocalist. This becomes another easy step of turning the input knob down. Even if a compressor is set properly, this input knob of the mic pre may slam the compressor too hard. After you’re satisfied with the input signal to your pre amp, well then, your next move is onto the mic itself.
In some cases, vocal distortion is caused by the microphone itself getting “slammed” too hard by the signal of the rapper (vocalist). To fix distortion in this case, you usually have a couple of options. One option is adjusting the mic’s reduction setting (some microphones have a reduction setting of up to -20 decibels). Another option addresses the rapper (vocalist)!
In many cases, especially hip hop/rap, the rapper (vocalist) may very well be too powerful for the microphone being used. Some rappers have voices that are very bass driven, which some mics cannot accommodate properly. Still, there are other rappers who have voices that may be too high pitched, especially when they’re screaming. These extreme frequencies can bring forth distortion no matter what settings are at one’s fingertips. If these vocals continue to jab at microphones that can not handle them, the mic will inevitably “die” (be seriously damaged). Thus, if and when you do find that the rapper (vocalist) is the cause of the distortion, the solution will most likely be a different microphone.
Bottom line: When it comes to finding and rooting out distortion on vocals, all avenues of the mic signal chain must be examined.
