Owner's manual

ManualsBrandsRane ManualsAudioAC 23 (1993 version)

Manual-1

AC 23

ACTIVE CROSSOVER

OPERATORS MANUAL

AC 23 CONNECTION

Balanced/Unbalanced Inputs

The ¼" Input jacks on the AC 23 are TRS (tip-ring-

sleeve). We recommend connecting the AC 23 with a bal-

anced cable from the balanced output of a mixer or equalizer.

If a balanced output is not available, and the cable run is

less than ten feet (three meters), inserting an unbalanced ¼"

TS (tip-sleeve) plug works in most situations.

Unbalanced Outputs

The ¼" Output jacks on the AC 23 are unbalanced TS

(tip-sleeve). We recommend that cables to the amplifiers be

no longer than ten feet (three meters).

See the “Sound System Interconnection” RaneNote

included with this manual for more information on cabling

and grounding requirements.

QUICK START

This is an automatic crossover! By automatic, we mean that the AC 23 is smart enough to know whether you want to

run it as a two channel crossover, or as a single channel unit. It knows by the way the plugs are inserted how your system is

to be configured. However, just because it is automatic, doesn’t mean that it will not automatically confuse you when you

try to connect it in a bench test situation. Note: 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.

Plugging a signal into the CHANNEL 1 INPUT and nothing into the CHANNEL 2 INPUT tells the unit that you are

running a single channel system in Mono 4- or 5-Way mode, and therefore sets the unit up to be a single channel device.

This can lead one to think that there are some dead channels in the unit when looking for output in places where there

shouldn’t be any. The even more automatically confusing part is the way that the Output connectors decide whether the unit

is a 4-Way or 5-Way crossover. It is actually rather straightforward.

To test the unit as a Mono 4-Way, first slide the CHANNEL 1 and 2 switches on the back to 3-WAY. Connect the

INPUT source to CHANNEL 1 only. Following the labels below the jacks, look at SUB OUT, then look at LOW OUT,

now go back to MID OUT, and then proceed to the HIGH OUT. So far, so good.

To test the AC 23 as a Mono 5-Way, the only precaution required is there must be a “dummy” plug (¼" unconnected

plug) inserted into the HI MID OUT to program the crossover properly. When you reach the point where you want to

measure the output of the channel with the dummy in it, simply remove it and insert your test output plug in that location.

When operating the AC 23 as a Stereo 3-Way, follow the diagram on page Manual-5, reading the labels above the jacks

and controls. To drive both Channels with a mono signal, connect only to the CHANNEL 2 INPUT. This approach is the

same as if you used a wye cable to both Inputs.

The AC 23B is available as a fully balanced output version equipped with XLR connectors (for inputs and outputs)

instead of the ¼" jacks. If you are connecting to balanced amplifiers from the AC 23 or are running crossover output cable

lengths greater than 10 feet (or 3 meters), we highly recommmend you purchase an AC 23B.

Never connect anything except an RS 1 or other approved Rane AC power supply to the thing that looks like a

telephone jack on the rear. This is an 18 VAC center-tapped power unit. Consult the Rane factory for replacement or

substitution.

WEAR PARTS: This product contains no wear parts.

Summary of content (18 pages)

PAGE 1
OPERATORS MANUAL AC 23 ACTIVE CROSSOVER QUICK START This is an automatic crossover! By automatic, we mean that the AC 23 is smart enough to know whether you want to run it as a two channel crossover, or as a single channel unit. It knows by the way the plugs are inserted how your system is to be configured. However, just because it is automatic, doesn’t mean that it will not automatically confuse you when you try to connect it in a bench test situation.
PAGE 2
FRONT PANEL: STEREO 2-WAY CONFIGURATION Observe the labels screened above the controls for stereo operation. NOTE: In the 2-Way mode, the AC 23 crossover range is from 190 Hz to 7 kHz. The model AC 22 crossover in stereo 2-Way mode is recommended when the crossover point needs to be outside of this range. * Not used in 2-Channel 2-Way Mode 햲 POWER switch: Two guesses. 햳 POWER indicator: When this yellow LED is lit the unit is ready to operate.
PAGE 3
REAR PANEL: STEREO 2-WAY INSTALLATION Observe the labels above the Inputs and Outputs for Stereo operation. 햲 CHANNEL 1 INPUT: These ¼" Inputs accept either balanced TRS (tip-ring-sleeve) or unbalanced TS (tip-sleeve) plugs. Connect the output of the mixer, equalizer or other signal source to this input. Note: Use this input only if you are running two separate channels from the mixer or other source. Connect this input to the left channel output of the mixer, equalizer or other signal source.
PAGE 4
FRONT PANEL: STEREO 3-WAY CONFIGURATION Observe the labels screened above the controls for stereo operation. 햲 POWER switch: Two guesses. 햳 POWER indicator: When this yellow LED is lit, the unit is ready to operate. 햴 CHANNEL 1 MASTER LEVEL control: Sets the overall Level of Channel 1 without altering the relative settings of the Low/Mid/High frequency Outputs. Unity gain for all Level controls is at “7”.
PAGE 5
REAR PANEL: STEREO 3-WAY INSTALLATION Observe the labels above the Inputs and Outputs for Stereo operation. 햲 CHANNEL 1 INPUT: These ¼" Inputs accept either balanced TRS (tip-ring-sleeve) or unbalanced TS (tip-sleeve) plugs. Connect the output of the mixer, equalizer or other signal source to this Input. Note: Use this input only if you are running two separate channels from the mixer or other source. Connect this Input to the left channel output of the mixer, equalizer or other signal source.
PAGE 6
FRONT PANEL: MONO 4-WAY AND 5-WAY CONFIGURATION Observe the labels screened below the controls for mono operation. 햲 POWER switch: Two guesses. 햳 POWER indicator: When this yellow LED is lit, the unit is ready to operate. 햴 MASTER LEVEL control: Sets the overall Level of the entire unit in Mono mode, without changing relative settings of the individual Sub/Low/Mid/High Outputs. Unity gain for all Level controls is “7”. 햵 SUBWOOFER LEVEL control: Sets the Level of signal going to the Sub Output.
PAGE 7
헂 Hl MID LEVEL control: This controls the Level of signal going to the Hi Mid Output only in 5-Way Mode. **NOTE TO 4-WAY MONO USERS: An internal jumper determines 4 or 5-Way mode. Our apologies: We must ship the units in the 5-Way mode since normal Stereo 3-Way operation demands it: a fact not the least bit obvious, but nevertheless, a fact it remains. See the section below for Mono 4-Way Jumper Instructions.
PAGE 8
REAR PANEL: MONO 4-WAY AND MONO 5-WAY INSTALLATION Observe the labels below the Inputs and Outputs for mono operation. 햲 MONO INPUT: These ¼" Inputs accept either balanced TRS (tip-ring-sleeve) or unbalanced TS (tip-sleeve) plugs. Connect the output from your mixer or other signal source only to the CHANNEL 1 INPUT for Mono operation—do not use the Channel 2 Input. As long as no plug is inserted into the Channel 2 Input the AC 23 will internally switch itself to Mono operation.
PAGE 9
REAR PANEL: ALTERNATE MONO 4-WAY INSTALLATION Note: The internal switching in the AC 23 will result in a Mono 4-Way configuration with the crossover sections arranged SUB, LOW, MID & HIGH from left to right across the front panel. By connecting a patch cable from the CHANNEL 1 HIGH OUT to the CHANNEL 2 INPUT, the LOW/MID crossover range changes from 70 Hz - 1 kHz to a higher range of 190 Hz - 7 kHz.Set the CHANNEL 1 switch to 3-WAY, and the CHANNEL 2 switch to 2-WAY.
PAGE 10
OPERATING INSTRUCTIONS Selecting Crossover Frequencies Most speaker manufacturers supply low and/or high frequency cut-off points for each driver, especially if these are supplied in a system. These cut-off frequencies are based on each driver’s performance at and beyond this point, with a certain safety margin to accommodate more gentle filter roll-offs and resultant higher output beyond the recommended performance range.
PAGE 11
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. 1.
PAGE 12
until the display shows +3 dB (red). The amount of displacement correction available from the Delay depends on the actual crossover frequency: the higher the frequency, the less amount of correction capability. If the drivers are built into a single cabinet and/or it is impossible to change relative positions, then you will have to obtain additional external delay to achieve proper phase alignment. iv.
PAGE 13
4. 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 Input or Mid frequency Level controls, turn up the HIGH LEVEL control until the tone coming from only the high driver reads 0 dB on the SPL meter. 5. Now release the MID MUTE switch so that the tone is emitted from both the high and mid drivers. Check the reading on the SPL meter: i.
PAGE 14
Delay vs. Frequency Table If you do not have the equipment necessary to electronically align the system as described in previous sections, you may use the table below to obtain a rough and approximate phase alignment of your drivers. Measure the horizontal displacement between the voice coils of the two adjacent drivers sharing the same crossover point, then find the column in the table nearest your actual displacement.
PAGE 15
Setting the Output Level Controls Choosing the crossover frequencies was the easy part. Now it gets real fun. The idea is to set the output Level controls on the crossover so that the entire speaker system has a uniform, flat response. Unfortunately, the room in which the speakers are placed has a habit of always getting into the act, so things get messy. As a result there seems to be two schools of thought regarding the use of active crossovers.
PAGE 16
Setting Levels Using an SPL Meter & Pink Noise Generator The MUTE switches on the AC 23 make using an SPL meter an easy and relatively accurate means of tuning a system. First, obtain a good SPL meter from a local electronics or hi-fi store. Second, and perhaps a little trickier, get a hold of a pink noise generator—again try electronics stores. You may also use a sweep or tone generator in place of a pink noise source.
PAGE 17
occasionally there is a need to delay the CD horn as its diaphragm is usually in front of the other drivers in the enclosure (see Fig. 5). If you are using CD horns, you should also read the CD horn EQ modification as described on page 18.With the AC 23 it is a little difficult to figure out which Delay to move to the High Frequency Output. The normal configuration for a speaker enclosure is shown in Fig. 3.
PAGE 18
Constant Directivity Horn Equalization Modification Monoing the Low Frequency Outputs Constant Directivity (or CD) horns need additional equalization to help cover the same area a long throw horn can cover. Additional circuitry has been added to the AC 23 for the additional equalization of the High Frequency outputs for the CD Horns. This modification should only be attempted by an experienced technician. It is important to know the 3 dB down point of the CD driver's frequency response.