User Manual

ManualsBrandsRane ManualsAudioAC 23B (1998 version)

Manual-1

AC 23B

ACTIVE CROSSOVER

OPERATORS MAN UAL

AC 23B CONNECTION

In agreement with IEC and AES/ANSI standards, AC 23B

wiring convention is pin 2 Positive, pin 3 Negative (return),

pin 1 Signal ground (for unbalanced use), with the connector

case or shell tied to chassis ground.

Balanced Operation

Use only when driving from a true balanced source and

driving to a true balanced destination—either transformer

coupled or active drive. Connect the input to pins 2 and 3 with

pin 2 positive. Do not connect pin 1. Terminate the shield to

the case or shell. Connect the output to pins 2 and 3 with pin

2 positive. Do not connect pin 1. Connect the shield to the

case or shell.

Unbalanced Operation

Connect the input between pins 2 and 1 with pin 2

positive and pin 1 Signal ground. Short pin 3 to pin 1.

Terminate the shield to the case or shell. Connect the output

between pins 2 and 1 with pin 2 Positive. Leave pin 3 open—

do not short it to pin 1. Connect the shield to the case or shell.

Combination Operation

For combined balanced and unbalanced operation, use

whichever half of the above instructions apply for each end.

See the “Sound System Interconnection” RaneNote

included with this manual for more information on cabling

and grounding requirements.

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.

The AC 23B is a fully balanced version of the popular AC 23 and is equipped with 3-pin (XLR-type) connectors instead

of the standard ¼" TRS jacks. A STEREO/MONO switch has been added to the AC 23B and should be set appropriately.

Switching jacks are not provided. All other specifications and operation are identical.

To operate the unit in Stereo 3-Way mode, be sure the rear panel switches are set for STEREO 3-WAY. Following the

labels above the controls and jacks in logical order, you will find CHANNEL 1 INPUT, LOW OUT, MID OUT, and HIGH

OUT, with the same for CHANNEL 2. The fact that the AC 23B is a multiple function unit means the outputs are switched

around in Mono mode. To use the unit as a Mono 5-Way, first check that the CHANNEL 1 and 2 switches are set to 3-

WAY, and the other switch is set to MONO. Connect the INPUT source to CHANNEL 1 only. Following the labels below

the jacks, look at SUB OUT, then look over at LOW OUT, now go back to MID OUT, then over to HI MID OUT and then

proceed to the HIGH OUT. An internal jumper determines 4 or 5-Way mode. Our apologies to 4-Way users: 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 neverthe-

less, a fact it remains. Pity. See page Manual-6 for Mono 4-Way configuration.

CAUTION: Never connect anything except an approved Rane Power supply to the thing that looks like a red tele-

phone jack on the rear of the AC 23B. This is an 18 VAC center tapped power input. Consult the Rane factory for a

replacement or substitution.

WEAR PARTS: This product contains no wear parts.

Summary of content (18 pages)

PAGE 1
OPERATORS MANUAL AC 23B ACTIVE CROSSOVER 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. The AC 23B is a fully balanced version of the popular AC 23 and is equipped with 3-pin (XLR-type) connectors instead of the standard ¼" TRS jacks. A STEREO/MONO switch has been added to the AC 23B and should be set appropriately. Switching jacks are not provided.
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 23B 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: Plug the left output of the mixer, equalizer or other signal source to this Input. See ‘AC 23B Connection’ on page Manual-1 for wiring details. 햳 CHANNEL 2 INPUT: Plug the right output of the mixer, equalizer or other signal source to this Input..
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: Plug the left output of the mixer, equalizer or other signal source to this Input. Refer to ‘AC 23B Connection’ on page Manual-1 for wiring details. 햳 CHANNEL 2 INPUT: Plug the right output of the mixer, equalizer or other signal source to this Input.
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
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. The HI MID LEVEL control, HI MID MUTE switch, HI MID DELAY control and HI MID/HIGH FREQUENCY control are out of circuit and will have no effect regardless of their settings in 4-Way Mode.
PAGE 8
REAR PANEL: MONO 4-WAY AND MONO 5-WAY INSTALLATION **THIS OUTPUT IS NOT USED FOR 4-WAY MONO OPERATION. 4-WAY USERS SEE JUMPER INSTRUCTIONS ON PREVIOUS PAGE. Observe the labels below the Inputs and Outputs for Mono operation. 햲 MONO INPUT: 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. See SYSTEM CONNECTION on page Manual-1 for wiring details.
PAGE 9
REAR PANEL: ALTERNATE MONO 4-WAY INSTALLATION Note: The switching in the AC 23B will result in a Mono 4-Way configuration with the crossover ranges 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. Switch CHANNEL 1 to 3-Way, and CHANNEL 2 to 2-Way. Note: DO NOT follow the Mono 4-Way Jumper Instructions on page Manual-7.
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
physically move the high driver farther forward 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. The Rane AD 22B would be suitable. 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 23B 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
Time Delay Transplant Modification There are modification jumpers inside the AC 23B. These jumpers permit the transplanting of the Delay circuits from one output to another. As the units are shipped, the Delay circuit is not installed on the High Frequency outputs. When the AC 23 was first designed, long throw horns were more common than Constant Directivity horns (CD horns). The long throw horn's diaphragm was the farthest sound emitter from the front of the speaker enclosure, (see Fig.
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 23B 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.