User manual SOUNDCRAFT GB2

[. . . ] GB2 User Guide GB2 User Guide 1 IMPORTANT Please read this manual carefully before using your mixer for the first time. © Harman International Industries Ltd. 2006 All rights reserved Parts of the design of this product may be protected by worldwide patents. ZM0344-01 Soundcraft is a trading division of Harman International Industries Ltd. Information in this manual is subject to change without notice and does not represent a commitment on the part of the vendor. [. . . ] In addition, the mains will also act as a carrier for many forms of RF interference generated by electric motors, air-conditioning units, thyristor light dimmers etc. Unless the earth system is clean, all attempts to improve hum noise levels will be futile. In extreme cases there will be no alternative but to provide a completely separate and independent `technical earth' to replace the incoming 'noisy earth'. However, always consult your local electricity supply authority to ensure that safety regulations are not being infringed. WORKING SAFELY WITH SOUND Although your new console will not make any noise until you feed it signals, it has the capability to produce sounds which when monitored through an amplifier or headphones can damage hearing over time. The table below is taken from the Occupational Safety & Health Administration directive on Occupational noise exposure (1926. 52): PERMISSABLE NOISE EXPOSURE DURATION PER DAY, HOURS 8 6 4 3 2 1. 5 1 0. 5 <0. 25 SOUND LEVEL dBA SLOW RESPONSE 90 92 95 97 100 102 105 110 115 Conforming to this directive will minimise the risk of hearing damage caused by long listening periods. A simple rule to follow is the longer you listen the lower the average volume should be. Please take care when working with your audio - if you are manipulating controls which you don't understand (which we all do when we are learning), make sure your monitors are turned down. Remember that your ears are the most important tool of your trade, look after them, and they will look after you. Most importantly - don't be afraid to experiment to find out how each parameter affects the sound - this will extend your creativity and help you to get the best results. Recommended headphone impedance is 50-600 ohms. 14 GB2 User Guide Setting Up & Troubleshooting Initial set-up Once you have connected up your system (see the sections on connection and wiring earlier in this manual for guidance) you are ready to set initial positions for the controls on your mixer. Set up individual input channel as follows: Connect your sources (microphone, keyboard etc. ) to the required inputs and release the MUTE switches. Note: Phantom powered mics should be connected before the 48V is switched on. Set Master faders at 0, input faders at 0, route the channels to MIX and set power amplifier level to suit the application. Provide a typical performance level signal and press the PFL button on the first channel, monitoring the level on the bargraph meters. Adjust the input gain until the meter display is in the amber section, with occasional peaks to the first red LED at a typical maximum source level. This allows sufficient headroom to accommodate peaks and establishes the maximum level for normal operation (but see note below). If you cannot achieve satisfactory input level setting without feedback, check microphone and speaker placement and repeat the exercise. If feedback persists, it may be necessary to use a Graphic Equaliser to reduce the system response at particular resonant frequencies. Note: The initial settings should only be regarded as a starting point for your mix. It is important to remember that many factors affect the sound during a live performance, for instance the channel EQ settings or even the size of the audience!You are now ready to start building the mix and this should be done progressively, listening carefully for each component in the mix and watching the meters for any hint of overload. If this occurs, back off the appropriate Channel Fader slightly until the level is out of the red segments, or adjust the Mix Master Faders. This procedure will ensure that the mixer is set up correctly, with adequate headroom. If more amplification is needed, adjust the power amplifier level controls. Troubleshooting No Power Is the mains supply present? [. . . ] Each post-fader group signal pair can be routed to the main mix stereo pair via the MIX switch (3). Each pair of groups, 1-2 and 3-4, has a WIDTH pot (4); it is used to adjust the group pair's signal within the stereo image of the main mix. The separation of the two group signals in the pair is maintained when the width pot is set to stereo, e. g. group 1 signal is routed to the main mix left bus, and group 2 is routed to the main mix right bus; when the width pot is fully at mono, a sum of group1 and group 2 is routed to the main mix left and main mix right busses. [. . . ]