User manual RANE AC 23S

[. . . ] OPERATORS MANUAL AC 23S ACTIVE CROSSOVER CH 1 MASTER LEVEL 4 2 0 10 6 8 2 0 10 2W: INACTIVE LEVEL 4 6 8 LOW MUTE 2 DELAY 4 6 8 MIN MAX 2W: INACTIVE 2W: LOW FREQUENCY LEVEL DELAY 240 400 MUTE 200 600 4 6 4 6 150 750 100 850 80 900 2 8 2 8 70 1k 0 10 MIN MAX LOW / MID MID 2W: LOW / HIGH FREQUENCY 700 1. 0k 550 2. 0k 475 2. 8k 350 4. 5k 250 5. 8k 190 7. 0k MID / HIGH HIGH LEVEL 4 2 0 10 6 8 2 CH 2 MASTER LEVEL 4 6 8 0 10 2 0 10 2W: INACTIVE LEVEL 4 6 8 LOW MUTE 2 DELAY 4 6 8 MIN MAX 2W: INACTIVE 2W: LOW FREQUENCY LEVEL DELAY 240 400 MUTE 200 600 4 6 4 6 150 750 100 850 80 900 2 8 2 8 70 1k 0 10 MIN MAX LOW / MID MID 2W: LOW / HIGH FREQUENCY 700 1. 0k 550 2. 0k 475 2. 8k 350 4. 5k 250 5. 8k 190 7. 0k MID / HIGH HIGH LEVEL 4 2 0 10 6 8 AC 23S ACTIVE CROSSOVER MONO MASTER SUBWOOFER SUB / LOW MID 4W: MID / HIGH 5W: MID / HIGH-MID MONO 4W OR 5W: INACTIVE LOW LOW / MID 4W: INACTIVE 5W: HIGH-MID 4W: INACTIVE 5W: HIGH-MID / HIGH HIGH POWER QUICK START Labels above the controls refer to the unit being operated in the 2- or 3-Way Stereo mode. Labels below the controls refer to the unit being operated in the 4- or 5-Way Mono mode. Set the STEREO/MONO switch appropriately. The fact that the AC 23S is a multiple function unit means the outputs are switched around in Mono mode. [. . . ] The one catch is that in many cases it is physically or otherwise impossible to get all the drivers vertically lined up at the sound source. By electronically delaying the signal going to the front driver, enough time allows the sound from the rear driver to literally catch up to the forward driver's voice coil, so that signal from both drivers is emitted in phase--and it works!Time delay makes an appreciable improvement in overall sound. The trick is finding the proper time delay amount: hence this manual. Unfortunately the amount of time delay is a function of two factors: the amount of horizontal displacement between driver voice coils, and the actual crossover frequency involved. Setting delay controls by ear is supposedly possible, but very tricky and unreliable. The following methods are a couple In-Phase Axis Response Without Time Delay of (but by no means all) means of setting time delay. Corrected In-Phase Axis with Time Delay on the Low Driver Manual-9 Time Delay Adjustment Using Realtime Analyzer & Pink Noise This method outlines the use of a realtime analyzer, pink noise generator and flat response microphone to set crossover time delay. Some references will be made to the Rane RA 30 realtime analyzer for those with the intelligence and good taste to use one of these regularly. The procedure applies to virtually any analyzer system. We recommend using a 1/3 or 2/3-octave analyzer as either of these is more likely to match your specific crossover points than a one-octave analyzer. And it is important to match the analyzer to the crossover point as closely as possible for proper phase alignment, otherwise the analyzer readings may be misleading. STEP BY STEP PROCEDURE A 3-Way mode consisting of High, Mid and Low drivers is used here as an example. For other configurations, use the same procedure starting with the highest crossover point and repeating steps 2 through 5 for each lower crossover point. NOTE: If you are running two separate channels on the crossover, tune up only one channel at a time, using the same procedure for both. Place the analyzer mic about 15 feet in front of the speaker stack and at a height about midway between the high and mid drivers. Turn all crossover LEVEL controls fully down. Connect the pink noise source to the crossover INPUT (or mixer or wherever is convenient). Turn up the crossover MASTER LEVEL control and the MID OUT control until noise is heard only from the mid driver at a comfortable volume. With a healthy but not uncomfortable volume of noise from the mid driver, set the analyzer DISPLAY LEVEL control so the LED's corresponding to the high crossover frequency are reading 0 dB (this would be a green LED at the crossover frequency with any of the Rane analyzers). For example, if your high crossover frequency is 2 kHz, set the RA 30 in the ±1 dB mode and then adjust the RTA LEVEL control until the green LED is lit in the 2 kHz band. Press in the MID MUTE switch on the crossover so the tone is removed from the mid driver. Without re-adjusting either the meter or the crossover Input or Mid Level controls, turn up the HIGH LEVEL control until the tone coming from the high driver reads 0 dB (a green LED at the crossover frequency). [. . . ] Now go back and re-adjust the previous crossover level controls, turning these down to get a 0 dB reading on the meter. Once the HIGH LEVEL control is set for 0 dB on the meter, disengage all of the MUTE switches on the crossover, and check that noise is emitting from all the speaker components. Make any overall level adjustments with the MASTER LEVEL controls and leave the output level controls unchanged. Manual-14 Monoing the Low Outputs It is possible to mono the Low Frequency Outputs of the AC 23S by an internal jumper. The unit should only be opened by qualified service personnel. [. . . ]