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. 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. To operate the AC 22S in Stereo 2-Way mode, be sure that the Mode switch is set for STEREO 2-WAY. [. . . ] 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. For other configurations, use the same procedure starting with the highest crossover point and repeat steps 2 through 5 for each lower crossover point. Set the tone generator to the highest crossover frequency and plug it into the Input of the crossover. Position the SPL meter (microphone) about 15 feet in front of the speakers and at a height about midway between the high and mid drivers. It is very important that the meter remain in exactly the same position throughout the test, so affix it to a mic stand, small tree or other stable object. Be sure to minimize background noise (air conditioners, fans, traffic, wild animals, etc. ) as these will effect the meter reading. Slowly turn up both the crossover MASTER and MID LEVEL controls until the tone is heard through the mid driver. Adjust the SPL meter control and/or the crossover LEVEL controls until you obtain a 0 dB reading on the meter. Verify that no sound is coming from any other speakers except the mid driver. Now press in the MID MUTE switch on the crossover so that the tone is removed from the mid driver. Without re-adjusting either the meter or the crossover MASTER or MID LEVEL controls, turn up the HIGH LEVEL control until the tone coming from only the high driver reads 0 dB on the SPL meter. Manual-8 5. [. . . ] Now slowly turn up the MID LEVEL control so pink noise is heard from the mid frequency speakers. Without changing any settings on the SPL meter, adjust the crossover MID LEVEL control until you obtain a 0 dB reading on the SPL meter. Now press the MID MUTE switch on the crossover so the pink noise again disappears. Repeat this process for each crossover frequency section, ending with the highest frequency. [. . . ]