Yamaha EMX5014C Owner's Manual - Page 17

Mixer Basics Making the Most of Your Mixer Ambience Your mixes can be further refined by adding ambience effects such as reverb or delay. On the EMX mixers these effects are built in. The internal DSP (Digital Signal Processor) can be used to add reverb or delay to individual channels in the same way as external effects processors, with the extra connections required by, or the loss in sound quality often caused by external processing. (Refer to page 22). You need to be careful not to overdo effects, however, because going to far can undermine the clarity and quality of your mix. Use your ambience effects just enough to create the required feeling of depth, but no more than is necessary to keep your sound clean. Reverb and Delay Time A variety of reverb and delay effect programs are provided, and nearly all of then have a reverb/delay time parameter than can be adjusted via the panel PARAMETER control. Small adjustments to the reverb/delay time can actually have a significant effect on the sound. The optimum reverb time for a piece of music will depend on the music's demo and density, but as a general rule longer reverb times are good for ballads, while shorter reverb times are more suited to up-tempo tunes. Delay times can be adjusted to create a wide variety of "grooves", and you need to select the time that best suits the music. When adding delay to a vocal, for example, try setting the delay time to dotted eighth notes corresponding to the tune's tempo. Reverb Tone Different reverb programs will have different "reverb tone" due to differences in the reverb time of the high or low frequencies, or differences in the overall frequency response of the reverb sound. Always be careful not apply too much reverb, particularly in the high frequencies. In addition to resulting in unnatural sound, excessive high-frequency reverb can interfere with the high frequencies in other parts of the mix. If you can hear more reverb than direct sound in the upper frequency range, try selecting a different effect program. It's always a good idea to choose a reverb program that gives you the depth you want without detracting from the clarity of the mix. Reverb Level It's amazing how quickly your ears can lose perspective and fool you into believing that a totally washed-out mix sounds perfectly fine. To avoid falling into this trap start with reverb level all the way down, then gradually bring the reverb into the mix until you can just hear the difference. Any more than this normally becomes a "special effect." You don't want reverb to dominate the mix unless you are trying to create the effect of a band in a cave-which is a perfectly legitimate creative goal if that's the sort of thing you're aiming for. The Modulation Effects: Phasing, Chorus, and Flanging All of these effects work on basically the same principle: a portion of the audio signal is "timeshifted" and then mixed back with the direct signal. The amount of time shift is controlled, or "modulated", by an LFO (Low-frequency Oscillator). When we say "time shift," however, we're not talking in terms of minutes or even seconds. For phasing effects the shift is very small indeed - a difference measured in degrees of phase shift rather than time units. The phase difference between the modulated and direct signals causes cancellation at some frequencies and reinforces the signal at others - a "comb filter" effect - and this causes the shimmering sound we hear. Phasing is the subtlest of all these effects, producing a gentle shimmer that can add life to a wide range of sources without being too obtrusive. For chorus and flanging the signal is actually delayed by several milliseconds (a millisecond is a thousandth of a second), with the delay time modulated by an LFO, and recombined with the direct signal. In addition to the comb-filter effect described above, the delay modulation in these effects causes a perceived pitch shift which, when mixed with the direct signal, results in a harmonically rich swirling or swishing sound. The difference between chorus and flanging effects is primarily in the amount of delay time and feedback used - flanging uses longer delay times than chorus, whereas chorus generally uses a more complex delay structure. Chorus is most often used to thicken the sound of an instrument, while flanging is usually used as an outright "special effect" to produce otherworldly sonic swoops. EMX5014C Owner's Manual 17