Alesis M-EQ230 User's Manual
Contents
1. 4 1KHz 0dBV INPUT NUMBER OF CHANNELS 2 NOMINAL LEVEL OdBV MAXIMUM LEVEL 18dBV IMPEDANCE 1MQ OUTPUT NUMBER OF CHANNELS 2 MAXIMUM LEVEL 18dBV IMPEDANCE 2400 FRONT PANEL CONTROLS 30 Band 1 3rd octave 12dB center frequencies set to ANSI and ISO standards INDICATORS Power Signal Present Clip and In Out LEDs per channel SWITCHES In Out REAR PANEL JACKS Input Left and Right 1 4 and RCA Output Left and Right 1 4 and RCA Power Barrel Jack POWER REQUIREMENTS 9 Volts AC 7 5 Volt Amps external transformer UL approved DIMENSIONS W x H x D 19 x 1 75 x 4 WEIGHT 2 5 Ibs2. AlesisM EQ 230 DUAL 1 3 OCTAVE PRECISION EQUALIZATION SYSTEM USERS MANUAL Alesis M EQ 230 DUAL 1 3 OCTAVE PRECISION EQUALIZATION SYSTEM INTRODUCTION The Alesis MEQ 230 is a two channel 30 band channel 1 3rd octave graphic equalizer which features a relay based power up delay switching circuit to eliminate turn on transients in sound systems Each channel features 30 bands of 1 3rd octave equalization with ANSI and ISO standard center frequencies Each band is adjusted by a center detented fader with 12dB of gain available and a master fader controls system gain for that channel Clip and signal present LEDs as well as a bypass switch are also provided on each channel Inputs and outputs for each channel are via both 1 4 and RCA jacks The unit can also be rack mounted in only 1 rack space FEATURES e 2 complete 30 band 1 3 octave equalizers in 1 rack space Power up delay circuitry protects speakers by eliminating turn on transients 12dB boost or cut per band Each channel can be bypassed individually Clip and signal present LEDs for each channel Inputs and outputs via both 1 4 phone and RCA jacks Applications Feedback control in sound systems Feedback control in stage monitor systems Timbre contour of musical instruments Room voicing Special sound effects SECTION 1 DESCRIPTION OF CONTROLS FRONT PANEL 1 3 OCTAVE BAND FADER Each 1 3rd octave band is controlled by a center detented fader which prov
3. NTROLLING FEEDBACK A Find the 2 major feedback frequencies 1 high 1 low frequency B Slightly decrease adjacent bands ROOM FEEDBACK FREQUENCIES ADJACENT BANDS SLIGHTLY DECREASED FOR INSTRUMENT TONAL CONTOURING 1 Find the desired frequency band by either referring to the Frequency Chart see Figure 5 or by experimenting 2 Gradually raise the slider of the disired band and the two adjacent sliders gradually until the desired result is achieved 3 Repeat as necessary If you should find that you are adding large amounts of EQ boost with more than half of the sliders boosted then the overall effect is the same as simply raising the volume level In this case do the following 1 With the instrument playing start by boosting 3 sliders at a time until the offending frequency area is found lf the Clip LED should light turn down the Input control 2 Now decrease the sliders until you are cutting the level instead of boosting 3 Experiment with the amount of decrease of the adjacent sliders as in feedback control see Figure 4B PLEASE NOTE The M EQ 230 and all other graphic Equalizers will sound best when the sliders show a gradual slope rather than a few wild boosts or cuts See Figure 4A and 4B Since the M EQ 230 can be used with any electric instrument or microphone requiring tonal alteration here are some generic suggestions as to setup Since each instrument will sound different due to the uni
4. VE RANGES FREQUENCY RANGE WHEN USED PRODUCES WHEN USED TOO MUCH THIS EFFECT PRODUCES THIS EFFECT 16Hz to 60Hz sense of power makes music muddy felt more than heard 60Hz to 250Hz Fundamentals of rhythm makes music boomy section EQing can change musical balance making it fat or thin 250Hz to 2000Hz Low order harmonics of telephone quality to music most musical instruments 500 to 1KHz horn like 1K to 2KHz tinny listening fatigue 2KHz to 4KHz Speech Recognition 3KHz listening fatigue lisping quality m v b indistiguishable 4KHz to 6KHz Clarity and definition of sibilance on vocals voices and instruments makes music seem closer to listener adding 6dB at 5KHz makes entire mix seem 3dB louder 6KHz to 16KHz Brilliance and clarity of sounds sibilance harshness on vocals As with any signal processor the M EQ 230 should be used with discretion since too much of a good thing can make the sound worse instead of better Although it is a wonderful device and will help your sound a lot remember that a little goes a long way If you re using the M EQ 230 for tonal contour of an instrument or voice Figure 5 will help you zero in on the key frequencies of some popular instruments Remember The chart serves only as a starting point Ultimately you must use your ears as a guide 10 SECTION 4 SPECIFICATIONS ELECTRICAL CHARACTERISTICS FREQUENCY RESPONSE 25Hz to 20kHz in 1 3 octave increments HARMONIC DISTORTION 00
5. ides a boost or cut of 12dB There are 30 bands per channel MASTER CHANNEL GAIN FADER Each channel has a Master Gain Fader which controls the system s input gain by 12aB CHANNEL BYPASS SWITCH Each channel s EQ can be individually bypassed by means of the Channel Bypass Switch The Master Gain Fader affects program input level only when the channel is not bypassed EQ IN LED The EQ In LED lights when the EQ is in use The LED will go out when a channel is bypassed CLIP INDICATOR The red CLIP INDICATOR LED indicates the onset of distortion 18 dB This LED should never light during normal use SIGNAL PRESENT LED The green SIGNAL PRESENT LED indicates that a signal is currently being fed into the M EQ 230 This LED lights at approximately 20dB and should be frequently lit during normal use POWER LED The POWER button turns the unit on or off BACK PANEL INPUT JACKS Left amp Right Accepts instrument to line level input signals for both left and right channels Both 1 4 and RCA phono jacks are provided OUTPUT JACKS Left amp Right Line level output of the M EQ 230 for both left and right channels Both 1 4 and RCA phono jacks are provided POWER JACK Accepts the 9VAC power from the M EQ 230 Power Supply This external supply keeps hum noise and ground loops to a minimum SECTION2 SET UP INSTRUMENTS MICROPHONES The Alesis M EQ 230 has high impedance inputs that are ideally suited for use either wi
6. queness of the instrument itself the type of music being played the arrangement and the touch of the player you must use your ears and the chart below to ultimately find the correct settings FIGURE 5 KEY FREQUENCIES FOR INSTRUMENTS INSTRUMENT KEY FREQUENCIES Bass Guitar Attack or pluck is increased at 700 or 1KHz Bottom added at 60 or 80Hz string noise at 2 5KHz Slap at 2 5KHz Bottom at 60 or 80Hz Fatness at 240Hz Crispness at 1 to 2 5KHz Bottom at 60 or 80Hz Hi Hat and Cymbals Shimmer at 7 5 to 10KHz Klang or gong sound at about 200Hz Attack at 5KHz Fullness at 240Hz Attack at 5KHz Fullness at 80 or 120Hz Electric Guitar Body at 240Hz Clarity at 2 5KHz Acoustic Guitar Body at 240Hz Carity at 2 5KHz Bottom at 80 or 120Hz Bass at 80 or 120Hz Presence at 2 5 to 5KHz Crispness at 10KHz Honky tonk sound at 2 5KHz as bandwidth is narrowed Resonance at 40 to 60Hz Fullness at 120 or 240Hz Shrill at 7 5 or 5KHz Voice Fullness at 120Hz Boominess at 200 to 240Hz Presence at 5KHz Sibilance at 7 5KHz Air at 12 to 15KHz Fat at 240H2 bite at 3 5kHz Resonant ring at 200 to 240Hz Presence and slap at 5KHz Whether used to alter the timbre of an instrument control feedback or improve speech intelligibility it s important to know what effect each portion of the frequency spectrum has on the sound In summary the frequency spectrum can be divided up into six important sections FIGURE 6 AUDIO OCTA
7. th instruments or line level signals Although microphones can be connected directly into the M EQ 230 it is recommended that for quietest operation they be connected to a mixing console first and then connected to the M EQ 230 as described in Figure 1 STEREO OPERATION For stereo operation of the M EQ 230 connect the left and right line outputs of the device to be equalized into the left and right inputs of the M EQ 230 See Figure 1 FIGURE 1 M EQ 230 STEREO OPERATION INDEPENDENT USE OF LEFT AND RIGHT CHANNELS The M EQ 230 need not be used in a stereo mode since each channel is completely independent In Figure 2 the right channel is connected to the house sound system for room tuning while the left channel is connected to the on stage monitor system for feedback control FIGURE 2 INDEPENDENT USE OF LEFT AND RIGHT CHANNELS Alesis 1622 MIXING CONSOLE AUX SEND OUT MAIN OUT or RIGHT OR LEFT MONITOR OUT MONITOR HOUSE POWER AMP POWER AMP INTERFACING VIA INSERT SENDS AND RETURNS Another way of interfacing the M EQ 230 is to connect the unit directly to the insert send and return patch points if your console has them of the channel that is to be effected See Figure 3 FIGURE 3 INTERFACING TO A MIXING CONSOLE VIA CHANNEL INSERTS SECTION 3 OPERATION POWER UP When the power is first turned on the automatic power up delay circuit will mute the M EQ 230 for 2 seconds This is to prevent any possible turn on
8. transient signal from mixers power amps or outboard equipment from possibly damaging speakers TO CONTROL FEEDBACK 1 Place all microphones in the positions where they will be used Set mics to approximate levels 2 Gradually bring up the sound system level until feedback just begins to occur 3 Feedback will usually occur at two frequencies in each room one low and one high Determine which frequency is loudest or that is feeding back first by decreasing each slider until one is found that makes the feedback disappear see Figure 4A 4 After the feedback frequency is found gradually increase the slider until just on the edge of feedback 5 Now gradually decrease the two adjacent sliders until the feedback again disappears see Figure 4B 6 Gradually increase the sound system gain until feedback occurs again 7 Repeat steps 3 4 and 5 PLEASE NOTE A ln many cases room acoustics uneven frequency response in speaker components and microphones excessive gain due to poor microphone technique poor placement of speaker systems or many open microphones in the sound system will all contribute to feedback which can only be mildly controlled but not totally eliminated If excessive EQ is being used it s best to try to correct some of the reasons for feedback first before resorting to EQ B For feedback control the sliders of the M EQ 230 should always be operated in the downward or cut position FIGURE 4 CO
Download Pdf Manuals
Related Search