User manual RANE AC 22S

[. . . ] OPERATORS MANUAL AC 22S ACTIVE CROSSOVER CH 1 MASTER 4 2 0 10 LEVEL 6 8 LOW MONO SUB 4 2 0 10 LEVEL 6 8 2 MIN MAX DELAY 4 6 8 LOW / HIGH 300 400 250 500 180 700 120 1. 0k 90 1. 5k 80 2. 0k 75 3. 0k 70 3. 6k FREQUENCY HIGH STEREO CH 2 MASTER 4 6 8 0 10 LEVEL 2 0 10 LEVEL 4 6 LOW INACTIVE: MONO SUB 4 8 2 MIN MAX DELAY 6 8 LOW / HIGH 300 400 250 500 180 700 120 1. 0k 90 1. 5k 80 2. 0k 75 3. 0k 70 3. 6k FREQUENCY HIGH 4 2 6 8 2 4 2 6 8 AC 22S ACTIVE CROSSOVER MUTE 0 10 LEVEL MUTE 0 10 LEVEL POWER MASTER LOW LOW / MID INACTIVE MONO INACTIVE MID MID / HIGH HIGH QUICK START The AC 22S can be either a Stereo 2-Way or Mono 3-Way crossover. To keep operation simple, remember this: Labels above the controls refer to the 2-Way Stereo mode. Labels below the controls refer to the 3-Way Mono mode. The fact that the AC 22S is a multiple function unit means the outputs are switched around depending on the SYSTEM MODE and SUBWOOFER switches on the back of the unit. [. . . ] There are a couple of ways to deal with this: a. Try to move the high driver back as far as possible without losing stability in balancing the speaker stack. You may want to raise it up as well to restore dispersion close to the stack. If you cannot move the high driver, then you will have to obtain an additional delay source to align the high and mid drivers, such as the Rane AD 22B. The built-in Delay system in the AC 22S is designed to accommodate the majority of common speaker configurations; if you encounter confusion or difficulty with your particular system, it is best to consult your dealer or the Rane factory for assistance. If this decrease in the display due to the DELAY control occurs at a low frequency crossover point below about 150 Hz, set the DELAY control to minimum and leave it there. Frequencies below 150 Hz are actually omnidirectional, so that phase misalignment is virtually inaudible below this point. Subwoofers will often possess long folded or straight horns, resulting in the diaphragm being well behind the rest of the stack. Most authorities agree that phase alignment of subwoofers is unnecessary. Otherwise you will have to obtain additional delay equipment to align these to the rest of the system. Lower the microphone until it is vertically midway between the mid and low drivers. Repeat steps 2 through 5, using the crossover LEVEL control, MUTE switch and next DELAY control. You may start each series of steps 2 through 5 at a different volume as necessary -- but once the Levels are set in step 3 do not alter these until step 5 is completed. Once all of the crossover DELAY controls are set, adjust the output LEVEL controls as outlined in the Setting Levels Section on page Manual-12. Time Delay Adjustment Using an SPL Meter & Tone Generator Now that good quality realtime analyzers are becoming more affordable and easier to use, there are few reasons why one of these should not be regularly used in any sound system. If an analyzer is simply not available or for some reason inappropriate, an accurate Delay setting can be obtained by using a straightforward SPL meter (obtainable at most local electronics stores) and some kind of variable tone generator. In order to exclude the effect of room acoustics and imperfect driver response, only the crossover frequencies are to be emitted (one at a time) by the tone generator. First, the highest crossover frequency is run through the crossover and each of the two speakers sharing the crossover point is set separately to an arbitrary 0 dB level on the SPL meter. When both drivers emit the crossover tone simultaneously, the combined response should read +3 dB higher on the meter. If the drivers are not phase aligned, some cancellation will occur on-axis, resulting in a combined response less than +3 dB. Turning the DELAY control up causes the lower frequency driver to electronically move backward until the SPL meter reads +3 dB; then the two drivers are electronically aligned and the on-axis cancellation is eliminated (see Figure 2 on page 6). This procedure is then repeated for the next lower crossover point(s). STEP BY STEP PROCEDURE A 3-Way mode consisting of high, mid and low drivers is used here as an example. [. . . ] Repeat this process for each crossover frequency section, ending with the highest frequency. NOTE: It is possible you may turn one of the frequency section output LEVEL controls all the way up and still not have enough volume for a 0 dB reading (as determined by previous section levels). This is probably due to different sensitivities of amps, speakers and other level controls in the system. When this happens, re-set the SPL meter so that it reads 0 dB on this frequency section (you may have to " down range" the meter and re-adjust the crossover MASTER LEVEL control). [. . . ]