Yamaha EMX512SC Owner's Manual - Page 15

BASIC Making the Most of Your Mixer Unbalanced noise Noise Source Cable Receiving device way, but a more systematic approach that is suited to the material you're mixing will produce much better results, and faster. There are no rules, and you'll probably end up developing a system that works best for you. But the key is to develop a system rather than working haphazardly. Here are a few ideas to get you started: Signal Levels and the Decibel Let's take a look at one of the most commonly used units in audio: the decibel (dB). If the smallest sound that can be heard by the human ear is given an arbitrary value of 1, then the loudest sound that can be heard is approximately 1,000,000 (one million) times louder. That's too many digits to deal with for practical calculations, and so the more appropriate "decibel" (dB) unit was created for sound-related measurements. In this system the difference between the softest and loudest sounds that can be heard is 120 dB. This is a nonlinear scale, and a difference of 3 dB actually results in a doubling or halving of the loudness. You might encounter a number of different varieties of the dB: dBu, dBV, dBM and others, but the dBu is the basic decibel unit. In the case of dBu, "0 dBu" is specified as a signal level of 0.775 volts. For example, if a microphone's output level is -40 dBu (0.00775 V), then to raise that level to 0 dBu (0.775 V) in the mixer's preamp stage requires that the signal be amplified by 100 times. A mixer may be required to handle signals at a wide range of levels, and it is necessary match input and output levels as closely as possible. In most cases the "nominal" level for a mixer's input and outputs is marked on the panel or listed in the owner's manual. Making Better Mixes Approaching the Mix-Where Do You Start? Mixing is easy, right? Just move the faders around until it sounds right? Well, you can do it that Faders Down It might sound overly simple, but it is usually a good idea to start with all channel faders off-all the way down. It's also possible to start with all faders at their nominal settings, but it's too easy to lose perspective with this approach. Start with all faders down, then bring them up one by one to fill out the mix. But which channel should you start with? Example1: Vocal Ballad Backed by Piano Trio What are you mixing? Is it a song in which the vocals are the most important element? + 20 dBu 0 dBu 0.775 V -20 dBu Most professional mixers, power amplifiers, and other types of equipment have inputs and outputs with a nominal level of +4 dBu. The inputs and outputs on home-use audio gear usually have a nominal level of -10 dBu. -40 dBu -60 dBu Microphone signal levels vary over a wide range depending on the type of microphone and the source. Average speech is about -30 dBu, but the twittering of a bird might be lower than -50 dBu while a solid bass drum beat might produce a level as high as 0 dBu. EMX512SC/EMX312SC/EMX212S 15