Bringing Clarity To The Element Of Time As It Relates To Sound

ProSoundWeb

For the most part, the time delays we’re talking about are so short that they can be discarded as irrelevant.

But not so fast! If the signals are being electrically recombined, then it is absolutely critical that they are not shifted in time – especially when dealing with different versions of the same signal.

For example, let’s say you put two mics on a guitar rig, and you’re mixing on one of those sexy new digital consoles.

Being a creative engineer, you pan the mics hard left and right, and then insert a cool tube compressor on one of the mics to get a fatter sound on the left side, while using the more dynamic sound from the right side.

All good. The stereo imaging just got wider, and you’ve made that boring guitar rig sound awesome.

But you notice a strange thing happening – when you cue up one mic or the other, each sounds good, but when you cue up both mics together, it sounds nasally and edgy.

Also, the mono feed to the center cluster sounds strange, as do the mono press feeds that are going on tonight’s news broadcast.

Pondering this annoying gremlin, you realize that by using the analog insert on the digital console, the digital to analog conversion and back has introduced a 1.2 millisecond delay on one of the guitar mics.

Normally, no big deal, as it’s too short to be noticeable timing issue – but when the two time-shifted identical or nearly identical signals are electronically recombined for the mono feeds, they cause audible cancellations.

Another common yet overlooked phenomenon is the effect that the 1.2 millisecond delay (and thus a 16-inch delay) of digital consoles has on the sound of in-ear monitor systems.

When singing, a performer hears the sound of his/her voice from two primary sources:

A) The voice itself and natural resonance of their body.
B) The ear buds jammed into their ears.

With analog, the sound of one’s own voice/body and the ear buds are pretty much perfectly timed. So perfectly, in fact, that you can actually and easily determine whether the mic is in polarity or not by singing and listening while flipping the console phase switch.

With digital, things get more complex. The absolute minimum time delay to the ear buds now becomes 16 inches, so perfect time alignment of the natural voice/body sound with the in-ear sound is no longer possible. The result is that the singer hears his or her own voice sounding “farther away” than with an analog console.

About now, I expect that some of you are saying, “This is silly. There’s no way that running in-ear mixes through a digital board causes this problem, and even if it does, no one even notices.”

But how do you think I discovered it?

First, by hearing it and then investigating why my voice sounded so far away from myself.

Second, by running one in-ear beltpack from an analog console and another beltpack from a digital console, and then with ear buds in my ears, plugging in back and forth between the two belt packs, using my own voice.

Every engineer I have demonstrated this to has heard it clearly.

Whether these types of time delay issues are a big deal or irrelevant depends on the expectations of the performers, the quality of gear, and several other factors.

Regardless, I’m confident that someday, somewhere, that by being aware of these time issues and having a clear understanding of what’s actually happening, you will save yourself some grief – and maybe even a gig.