SUB MIXING WITH THE GROUPS
For live sound reinforcement, the 8 Groups are mainly used for mixing sub groups of channels and providing alternate master outputs for sur- round sound mixes, center clusters and extension speakers systems. Sub mixing with the Groups is where several channels with a common- ality are assigned on the channel to a Group (or Group pair for stereo). Then the Group is assigned to the L-R masters. The advantage is being able to adjust the group with one fader (or two faders for stereo). This would be used for a drum set using multiple mics. In sound check, the 4 individual microphones are adjusted for each drum, then adjusted as a group for leveling each drum for a total drum set sound. Later when the full band is playing, the drum set can be brought up and down with the one Group fader without disturbing the channel faders.
Also, sub-mixing can bring the advantage of one Group insert for control over several channels. This is where one compressor can be inserted to cover a full drum set reducing the number of compressors needed.
The Groups are also equipped to perform as master outputs. Here is where the Groups help support center clusters, extension speakers for reaching distant listeners and surround sound speakers for effects when the L-R masters are used for the Left and Right speakers.
A LIVE SOUND SYSTEM.
Figure 6-4shows a typical live setup with the S/L console. All of the outboard gear is shown here in order to show its integration into the S/L console. The inputs are mostly mics, but because the console is distant from the stage, these mics and other inputs will be traveling through a “snake” cable. A snake is a cable carrying all connections to and from the stage to the console. Typically, a snake will only accept XLR bal- anced connections. This is why the Keyboard is shown connected through a “direct box” (Carvin DB3) which converts the unbalanced 1/4” out- puts of the keyboard to balanced XLR outputs for the console. Often the “direct box” will also “ground” isolate the instrument from the console in order to reduce hum and ground noise.
The next section of Figure 6-4is the “front-of-house” rack usually containing compressors, effects units and graphic EQ’s. These units are used at the inserts of the channels and at the master inserts for compressing vocals and drums, adding EQ or gates to background vocals and drums. Also, in the “front-of-house” rack will be the main graphic EQ’s for room equalization on the house speakers. The 6 XLR outputs con- nected at the 1-4 XLR GROUP OUTPUTS and LEFT/RIGHT master outputs are for four stage monitor mixes via the AUX 1-4 FLIP switches. The LEFT and RIGHT master FADERS control the left and right main speaker clusters. The main mix may be in stereo or mono with the left and right control for room balancing. Typically a room’s seating arrangement cannot be not setup properly for a true stereo performance. But having con- trol over the two sides of the stage and even a separate feed for subwoofers can help the sound engineer control room acoustics and feedback. The four monitors are pre fader AUX 1-4 stage monitors going through the on-stage rack of graphic equalizes for feedback reduction. Often in simpler systems, the monitors do not get the attention needed to help the performers do their best on the stage. Whenever possible, test out the monitors and be sure the power level of the monitors is adequate for the expected stage level of the performance. A good monitor system makes the performers comfortable and therefore more focused on their best performance.
THE SOUND CHECK
The sound check takes some skill but mostly patience from the performers and especially you the system operator. If you get frustrated during the sound check, the performers can lose confidence and the sound may suffer due to things missed in the sound check. The basic sound check follows this format: First test all microphones and other input devices (direct boxes, etc.) before the performers are included in the sound check. A good thing to also check here is feedback in the monitors from the microphones. Good positioning of the monitors and the use of a graphic equalizer solves most major monitor feedback problems. Now for a sound check with the performers. First set the level of each performer indi- vidually and in cases where a performer has multiple microphones, such as with drummers, set each drum mic individually then the drum set as a whole. This is also a good time to make some channel tone control adjustments to tailor the sound of the individual performers and instru- ments. After setting each individual, have the performers run through a song. Don’t hesitate to stop the performers if something needs to be adjusted or if a performer or microphone needs to be heard solo again. Remember the sound check is not a rehearsal, but a system check. It is always a good idea for the mixer operator to have a microphone to inform the performers of what is needed during the sound check. If a monitor system is being used, the mixer operator’s microphone should only be heard through the monitors when addressing the on stage per- formers, especially if something needs to be checked during the show. If the sound check is allowed to run through its full course, the system should run smoothly at show time.
