Rane ME60S Instruction Manual - Page 7

Operating Instructions Insuring the proper level of gain though the ME60S is just as important as adjusting the equalizer bands. Improper gain distribution is a common cause of loss of system headroom and less than optimum noise performance. The OverLoad LED informs of an imminent or passed overload to the equalizer. Occasional blinking of the OL with program source material is fine, indicating optimized signal to noise performance of the ME60S. Run the ME60S with an input signal that is as hot as possible without the OL lighting more than occasionally. The BYPASS switch allows comparison of equalized versus un-equalized signal. It is also useful in adjusting the level of the ME60S for unity gain or best signal-to-noise performance. The gain of the ME60S is optimized and at unity when there is no sound level difference between the bypassed and the active positions. The overall gain range of the LEVEL control for the ME60S is off to +2 dB for unbalanced operation, or off to +8 dB for balanced operation. The level difference between the equalizer in Bypass or active can be significant. Adjust the LEVEL control so the signal level is the same between the bypassed and active positions of the BYPASS switch. GETTING STARTED Here is one method of setting your equalizer that works well. Begin with the following settings: 1. Engage the BYPASS switch. (switch depressed, BYPASS LED on.) 2. Put all sliders in their center position (0 dB). The center posi- tion has a grounded detent. 3. Position the CHANNEL LEVEL controls about "7" for un- balanced operation and "6" for balanced operation. 4. Set LOW and HIGH CUT filters fully down, corresponding to 10 Hz and 40 kHz. 5. Apply a signal to the system. 6. Verify the OL LED is not on-occasionally blinking during extreme peaks indicates an optimal setting. But if it lights up a lot or lights steadily, lower the output level of the previous device in the signal chain. 7. Release the BYPASS switch and begin adjusting the equalizer filters. 8. During filter band adjustments, if the OL LED lights more than occasionally, turn down the output of the previous device in the signal chain. 9. Once all filter bands are adjusted to your liking, compare the signal loudness with the equalizer bypassed and active. Adjust the LEVEL controls on the ME60S so there is no difference between the levels of bypassed versus active. 10. The last step is to reconfirm that the OL LED lights only when there are large signal spikes in the program material, as in step 6 above. For insight into how to use an equalizer, to alleviate acoustic problems or to adjust the overall tone of the program material, please read the next two sections. ACOUSTIC COMPENSATION A graphic equalizer may be used to correct many acoustic problems. However, one should fully understand the ramifications of doing so. Acoustic problems are generally not consistent across the entire area of sound coverage. This is much more of a problem when setting up a sound system for large venues. In a typical large room or hall, there will be areas that have acoustic reinforcement problems and other areas where certain frequencies are almost entirely canceled out. Try to seek an acoustic remedy for acoustic problems whenever possible. When this is not possible or feasible, an equalizer may be used to compensate for an acoustic problem. But the problem is only improved at the point where the measurement is taken; other locations in the room may be adversely affected by the equalizer setting. For this reason, measure the acoustic response of the system from several locations and average the equalizer's setting. Doing this helps most locations in the venue to have an equal sound quality. The best way to "see" what the acoustic signature of the room is doing to sound is to use a real time analyzer or any of the many computerized measurement systems. Using these devices to analyze the response of the room and the sound system is the only accurate means available for setting an equalizer properly. Equalization can be like spice in the hands of a master chef. A little goes a long way in improving sound quality, too much and the mix is spoiled. If modest amounts of equalization (6-8 dB) do not solve the problem, it is best remedied by other means. Avoid adding large amounts of boost below 63 Hz, especially when using vented bass cabinets. Boosting frequencies below the vented enclosure's low frequency cutoff can easily cause over excursion of the speaker's cone, causing premature failure. In addition, boosting low frequencies can make your power amplifier run hotter, leading to premature amplifier failure. When equalizer adjustment is completed, compare the unequalized sound with the equalized sound by alternately engaging the BYPASS switch. Use familiar source material and walk around in the sound coverage area to insure that no anomalies have been introduced into the sound system. If it sounds good, you're done. TONE CONTOURING If a ME60S is used for tone contouring by ear, be careful about adding upper bass (63 Hz to 200 Hz) as this can cause "muddiness" or loss of clear definition. (Also see the previous warning about boosting frequencies below 63 Hz.) Middle frequency problems usually express themselves by vocals having a nasal quality (too much mid band boost) or vocals not being easily understandable (usually caused by mid band frequencies being under represented in the overall sound). High frequency problems show as "sizzle"- not good, and is sometimes caused by too much high frequency boosting. This is most obvious with cymbals and hi-hats. To use the cooking metaphor, high frequencies should simmer, not sizzle. ©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5000 TEL 425-355-6000 FAX 425-347-7757 WEB rane.com Manual-4