User manual RANE SEQ 30L

[. . . ] 0 dB gain is reached at the center detent with all sliders centered at their 0 dB detents. Set the INPUT LEVEL to give equal volumes with the EQ switched to ACTIVE or BYPASS, after setting the sliders (see EQ BYPASS switch below). Apply sufficient signal to the input to occasionally light the +4 dBu indicator. Flashing of the OL (overload) LED during peaks can be avoided by turning the INPUT LEVEL or boosted filters down. [. . . ] Both what and why you are equalizing determines where you install it. WHAT AND WHY Tone contouring is accomplished primarily by ear. Be careful though, not to boost too much bass. Be aware that the SEQ 30L is capable of boosting signals up to 12 dB (4 times as large!)--a level at which great care should be taken to prevent seismic disturbances. Optimal gain setting is indicated by the +4 dBu indicator lighting occasionally, while the OL indicator does not light. The SEQ 30L can be used to align crossovers and flatten speaker response. The best way to "see" what your sound system is doing, is to use a realtime analyzer, such as the Rane RA 30. A 1/3-octave realtime analyzer is an accurate means for setting a 1/3-octave equalizer properly. WHERE For tone contouring, the equalizer may be used at any point in the signal chain, such as insert loops in a mixer to equalize a single instrument, sweeten a tape recording, etc. When an equalizer is used for acoustical correction, the equalizer should be one of the last pieces of gear in front of the amplifiers and active crossover. Here are a few general guidelines to decide where to install the EQ in the system. Downstream of the Compressor Since system EQ is aimed at controlling acoustic problems, install it after any compressor, which is designed to operate on electrical signal. For one thing, the equalizer slider settings will change in each room location, which in turn affects the control voltage and threshold responses of the compressor, rendering it inconsistent. Secondly, large amounts of boost often cause tone differences by causing some frequencies to limit or compress before others. After any System Gain The best configuration is: mixer, compressor/limiter, equalizer, crossover, then power amplifier. Whenever headroom allows, try to take all the gain at the mixer, and run unity levels from then on. This also gives better noise performance through the system. Connect the SEQ 30L before the amplifier or active crossover. Take any required line gain before the SEQ 30L. Avoid taking a lot of gain in the crossover or power amps as this may create noise problems. The SEQ 30L operates at unity gain with the INPUT LEVEL control at the 0 dB center detent when sliders average to center (0 dB). You can test this with the EQ BYPASS switch--adjust the INPUT LEVEL control so that volume does not change when switching between Active and BYPASS. [. . . ] Since you are starting from a "tuned" system, your ear will not be fooled into thinking bass is too high when actually mids are too low, or that highs are too weak when really the mids are too strong. Fact: analyzers don't have good taste--people do. Analyzers consistently and accurately "tell it like it is, " but ultimately, personal judgment determines what sounds good or appropriate for the program material. In fact, final optimum EQ settings, made after analyzer testing, will vary greatly depending on the type of music, sound pressure level, size of the venue and disposition of the audience. [. . . ]