Making the Most Of Your Mixer
An Introduction
This tutorial helps first-time mixer users understand the basics for better performance and mixes.
1 A Place For Everything and Everything In Its Place
1-1. A Plethora Of Connectors—What Goes Where?
Understanding the different types of connectors is essential for setting up your system.
The Venerable RCA Pin Jack
This is the "consumer connector," commonly used on home audio gear. Also known as "phono" jacks, they are always unbalanced and generally carry a line-level signal at -10 dB, nominal. You'll likely use this type for connecting CD players or other home audio sources to your mixer, or for connecting your mixer's output to a cassette recorder.
The Versatile Phone Jack
Originally used in telephone switchboards, phone jacks can be tricky as their signal type isn't always obvious. They can be unbalanced mono, unbalanced stereo, balanced mono, or an insert patch point. The connector's label or the owner's manual will specify the signal type. A phone jack handling balanced signals is often called a "TRS" (Tip-Ring-Sleeve) phone jack.
The Sturdy XLR
Generally referred to as "XLR-type," this connector almost always carries a balanced signal. If the circuitry is designed properly, XLR-type connectors can also handle unbalanced signals. Microphone cables and most professional audio gear inputs/outputs typically use this type.
1-2. Balanced, Unbalanced—What's the Difference?
The key difference is "noise" rejection. Balanced lines are highly effective at rejecting random electromagnetic radiation (noise) picked up by cables, especially over long runs. If your setup is confined to a desktop with short connections (1-2 meters) and a relatively noise-free environment, unbalanced lines may be fine. However, balanced lines are almost always used for microphone cables because microphone output signals are very small, making even tiny amounts of noise relatively large and amplified.
To summarize:
- Microphones: Use balanced lines.
- Short line-level runs: Unbalanced lines are fine if you're in a relatively noise-free environment.
- Long line-level runs: Balanced is best, as the ambient electromagnetic noise level is the ultimate deciding factor.
How Do Balanced Lines Reject Noise?
Balanced lines operate on the principle of "phase cancellation." If two identical signals are added out of phase (one inverted relative to the other), they cancel each other out, resulting in no signal. A balanced cable has three conductors: a ground conductor (no signal), a "hot" or "+" conductor (normal-phase audio signal), and a "cold" or "-" conductor (reverse-phase audio signal). While the desired audio signals in the hot and cold conductors are out of phase, any noise induced in the line will be exactly the same in both conductors and thus in phase. The trick is that at the receiving end, the phase of one signal is reversed. This causes the desired audio signals to become in-phase and the induced noise to become out of phase, effectively canceling the noise while leaving the audio signal intact.
1-3. Signal Levels—Decibel Do's and Don'ts
The term "decibel" (dB) is a versatile unit for acoustic sound pressure and electronic signal levels. While variations like dBu, dBV, and dBm exist, understanding a few basics is sufficient:
- "Consumer" gear (home audio equipment) typically has line inputs and outputs with a nominal (average) level of -10 dB.
- Professional audio gear usually has line inputs and outputs with a nominal level of +4 dB.
- Always feed -10 dB inputs with a -10 dB signal. Feeding a +4 dB signal into a -10 dB input can overload it.
- Always feed +4 dB inputs with a +4 dB signal. A -10 dB signal is too small for a +4 dB input and will result in less-than-optimum performance.
- Many professional and semi-professional devices have level switches on inputs/outputs to select -10 or +4 dB. Set these to match connected equipment.
- Inputs with a "Gain" control, like the mono-channel inputs on your Yamaha mixer, accept a wide range of input levels because the control matches input sensitivity to the signal.
2 Where Your Signal Goes Once It's Inside the Box
Even complex mixer block diagrams can be understood by familiarizing yourself with the basic signal flow.
2-1. Greatly Simplified Mixer Block Diagram
A simplified signal path within a mixer typically includes:
- Head Amp: The first stage, providing significant "gain" or amplification. It adjusts the mixer's input sensitivity, amplifying small signals (e.g., microphones) and attenuating large signals.
- Equalizer: Can range from simple bass/treble controls to multi-band parametric EQ. Applying EQ boost adds gain and can overload the input channel; cutting is generally preferred.
- Channel Peak LED & Fader: The peak LED, located after the head amp and EQ, is crucial for setting input "gain." The fader controls the channel's output level.
- Summing Amplifier: This is where the actual "mixing" takes place, combining signals from all assigned input channels.
- Master Fader & Level Meter: A stereo, mono, or bus master fader controls the main output level, indicated by the mixer's level meter.
3 The First Steps in Achieving Great Sound
Properly setting levels for each individual source is vitally important for optimum mixer performance, even before considering EQ or effects.
3-1. The Head Amplifier “Gain” Control Is the Key!
Every stage in a mixer's signal path (head amp, EQ, summing amplifier, buffers) adds some noise. The amount of noise added by each stage is generally not significantly dependent on the audio signal level. This means a larger desired signal relative to the added noise results in a better "signal-to-noise ratio" (S/N ratio).
Basic Rule: To achieve the best overall system S/N ratio, amplify the input to the desired average level as early as possible in the signal path (at the head amplifier). However, too much initial gain will overload channel circuitry and cause clipping.
3-2. Level Setup Procedure For Optimum Performance
A general outline for setting levels:
- Start by setting all level controls (master faders, channel faders, input gain) to their minimum. Ensure no EQ is applied (no boost or cut), and all effects and dynamic processors in the system are defeated or bypassed.
- Apply the source signal to each channel one at a time. Have singers sing, players play, and playback devices play back at the loudest expected level. Gradually turn up the input gain control for the corresponding channel until the peak indicator begins to flash, then back off a little so that the peak indicator flashes only occasionally. Repeat for each active channel.
- Raise your master fader(s) to their nominal levels (the "0" markings on the fader scale).
- With all sources playing, you can now raise the channel faders and set up an initial rough mix.
Always monitor the main output level meters to ensure you don't constantly stay in the "peak zone." If output levels are consistently peaking, lower the channel faders until the overall program falls within a good range, depending on your program material's dynamic range.
4 External Effects and Monitor Mixes
4-1. AUX Buses For Monitor Sends and Overall Effects
AUX (Auxiliary) buses allow you to "tap" the signal flowing through your mixer at a point before the main outputs. Common uses include creating a monitor mix separate from the main mix, and processing signals via an external effect unit. Mixers with multiple AUX buses can handle various monitoring and processing needs.
Using AUX buses and level controls is straightforward. The main consideration is whether you need a "pre-fader" or "post-fader" send. AUX sends often have a switch to configure this.
Pre/Post—What's the difference?
| Pre-fader Send | Post-fader Send |
|---|
| A signal taken from a point before the channel fader. The send level is affected only by the AUX send level control and not by the channel fader. Commonly used to provide monitor mixes. | A signal taken from a point after the channel fader. Its level is affected by both the AUX send level control and the channel fader. Commonly used with the mixer's AUX or effect returns for external effect processing. |
Pre-fader send for a monitor mix: The send signal is fed to the monitor power amplifier and speaker system. The channel fader does not affect the send level, so the monitor mix remains independent of the main mix. No return signal is used in this case.
Post-fader send for external effects processing: The send signal is fed to an external effect unit (e.g., a reverb unit). The output from the effect unit is returned to the AUX Return jack and mixed back into the main program. The send level is affected by the channel fader, ensuring the effect level always remains in proportion to the channel signal.
4-2. Channel Inserts for Channel-specific Processing
Channel inserts provide another way to route a mixer's signal externally. They are almost always located before the channel fader and, when used, interrupt the mixer's internal signal path. Unlike AUX sends, channel inserts apply only to their corresponding channel. They are commonly used for dynamics processors (compressors, limiters) but can be used with any in/out processor.
When a plug is inserted into the channel insert jack, the internal signal path is interrupted and sent outside the mixer for external processing.
Channel insert jacks require a special "Y" insert cable with a TRS phone jack on one end and mono phone jacks on the split "Y" end. One mono jack carries the "send" signal to the external processor's input, and the other carries the "return" signal from the processor's output.
The signal output from the INSERT I/O jacks is reverse-phased. This is not a problem when connecting to an effector. However, if using the jack to output to an external device, be aware of possible phase conflicts with other signals.
5 Making Better Mixes
5-1. Approaching the Mix—Where Do You Start?
While simply adjusting faders can work, a more systematic approach tailored to your material will produce better and faster results. Developing a system is key.
Faders Down
It's usually best to start with all channel faders at their minimum. This helps maintain perspective. Bring them up one by one to build the mix.
Example 1: Vocal Ballad Backed by Piano Trio
If vocals are the most important element, build the mix around them. Bring the vocal channel to nominal first, then add the piano, adjusting the vocal/piano relationship. Finally, bring in the bass and drums to support the overall sound.
Example 2: Funky R&B Groove
For a groove-centric R&B number, most engineers start with the drums, then add the bass. The relationship between drums and bass is crucial for achieving the "drive." Pay attention to how the bass works with the kick drum, aiming for them to sound like a single instrument (kick supplying punch, bass supplying pitch).
Music First—Then Mix
Always prioritize the music. Let it guide your mix, focusing on what the music is conveying and which instrument or technique drives the message. Mixing is an art, and your mixes should become a vital part of the music.
5-2. Panning For Cleaner Mixes
Panning individual channels determines instrument placement in the stereo sound field and provides "space" to prevent conflicts, especially for instruments in similar frequency ranges. Recorded stereo sound is essentially 2-dimensional, so proper positioning is important.
5-3. To EQ Or Not To EQ
Generally, "less is better." Use EQ sparingly, especially boost. Proper EQ can eliminate interference and improve overall sound definition. Bad EQ, particularly excessive boost, sounds terrible.
Cut For a Cleaner Mix
Cutting frequencies is often more effective than boosting. For example, cutting low EQ on cymbal channels can create a more "spacious" mix and better definition in lower ranges without changing the cymbal sound. Similarly, rolling off low-frequency on piano or high-end on kick drums/bass guitars can create space, unless a specific character like "snap" is desired.
Boost With Caution
Boost only for special effects or in very small increments for a good-sounding mix. A tiny midrange boost can add vocal presence, or a touch of high boost can add "air." Listen carefully; if things don't sound clear, try cutting frequencies that clutter the mix rather than boosting for clarity. Too much boost adds gain, increasing noise and potentially overloading subsequent circuitry.
5-4. Ambience
Judicious application of reverb and/or delay via the mixer's AUX buses can polish a mix, but excessive use can "wash out" the mix and reduce clarity. How you set up your reverb sound significantly impacts its integration with the mix.
Reverb/Delay Time
Different reverb/delay units offer various capabilities, including adjusting reverb time. Matching reverb time to the music's tempo and "density" is crucial. Slower tempos and sparser mixes can sound good with longer reverb times, while faster, more active music requires shorter times.
Reverb Tone
The "brightness" or "bassiness" of a reverb sound greatly impacts the mix. Too bright reverb can sound unnatural and interfere with delicate highs. Reducing reverb brightness allows for full-bodied ambience without compromising clarity.
Reverb Level
It's easy to lose perspective and believe a washed-out mix sounds fine. To avoid this, start with reverb level at minimum, then gradually bring it in until it's just audible. More than this typically becomes a "special effect." Avoid letting reverb dominate the mix unless aiming for a specific creative goal (e.g., a band in a cave).
Appendix
Specifications
General specifications for the Yamaha MG10/2 mixing console are provided below:
- Frequency Characteristics (ST OUT): 20 Hz-20 kHz +1 dB, -3 dB @+4 dBu, 10 kΩ (with gain control at minimum level).
- Total Harmonic Distortion (ST OUT): 0.1% (THD+N) @+14 dBu, 20 Hz-20 kHz, 10 kΩ (with gain control at maximum level) (CHs 1 and 2).
- Hum and Noise: Equivalent input noise (CHs 1 and 2): -128 dBu. Residual output noise (ST OUT): -100 dBu (ST, Master fader at nominal level and all Ch at minimum level). All channel AUX controls at minimum level: -85 dBu. ST, Master fader and one Ch fader at nominal level: -64 dBu (CHs 1 and 2).
- Maximum Voltage Gain: Various gains are specified for different input to output paths, e.g., 76 dB for CH MIC INPUT to ST OUT.
- Monaural/Stereo Input Gain Control: 44 dB variable.
- Monaural/Stereo High Pass Filter: 80 Hz 12 dB/octave.
- Crosstalk (1 kHz): -70 dB between input channels, -70 dB between input/output channels (CHs 1 to 6).
- Monaural/Stereo Input Channel Equalization: HIGH 10 kHz shelving, MID 2.5 kHz peaking, LOW 100 Hz shelving. Max. Variation: ±15 dB.
- Monaural/Stereo Input Peak Indicator: Red indicator lights if post-EQ signal (on ST channels, if either post-EQ signal or post-mic-amp signal) comes within 3 dB of the clipping level.
- Level Meters: Two 12-point LED meters [Stereo (L, R)]. Peak point: red indicator. +5, +3, +1, and 0 points: yellow indicators. -1, -3, -5, -7, -10, -15, -20: green indicators.
- Phantom +48 VDC Power (Balanced input): Supplied when Phantom +48 V switch is ON.
- Included Accessory: Power adaptor (PA-10).
- Option: Microphone-stand adaptor (BMS-10A).
- Power Supply: Varies by region (e.g., USA and Canada: 120 V AC, 60 Hz; Europe: 230 V AC, 50 Hz; Australia: 240 V AC, 50 Hz; Korea: 220 V AC, 60 Hz).
- Power Consumption: 19 W.
- Max. Dimensions (W x H x D): 251 x 65 x 290.5 mm.
- Weight: 1.8 kg.
Where 0 dBu = 0.775 V and 0 dBV = 1 V.
Input Specifications
A detailed table outlines the specifications for various input connectors, including gain, input impedance, appropriate impedance, sensitivity, rated level, maximum level before clipping, and connector specifications. This includes MIC INPUT (XLR), LINE INPUT (TRS Phone), ST CH MIC INPUT (XLR), ST CH LINE INPUT (TRS Phone), ST CH INPUT (TRS Phone/RCA), CH INSERT IN (TRS Phone), AUX RETURN (TRS Phone), and 2TR IN (RCA).
Output Specifications
A detailed table outlines the specifications for various output connectors, including output impedance, appropriate impedance, rated level, maximum level before clipping, and connector specifications. This includes ST OUT (TRS Phone), AUX SEND (TRS Phone), CH INSERT OUT (TRS Phone), REC OUT (RCA), C-R OUT (TRS Phone), and PHONES (Stereo Phone).
Specifications and descriptions in this owner's manual are for information purposes only. Yamaha Corp. reserves the right to change or modify products or specifications at any time without prior notice. Since specifications, equipment or options may not be the same in every locale, please check with your Yamaha dealer.
European models conform to EN55103-1 and EN55103-2. Inrush Current: 3A. Conforms to Environments: E1, E2, E3 and E4.
Dimensional Diagrams
The manual includes diagrams illustrating the physical dimensions of the MG10/2 mixing console, with measurements provided in millimeters (251 x 65 x 290.5 mm).
Block Diagram and Level Diagram
Complex diagrams illustrating the internal signal flow and level paths within the mixer are provided. For a detailed understanding of the signal processing chain and gain staging, refer to the original manual's block and level diagrams.
