Rane AC 23B User manual

AC 23B
ACTIVE CROSSOVER
Data Sheet-1
Features
• Stereo 2- or 3-Way, Mono 4- or 5-Way
• Linkwitz-Riley Alignment with 24 dB per Octave Slopes
• Adjustable Delays
• Infrasonic, Ultrasonic and RFI Filters
General Description
e Rane AC 23B Active Crossover can be configured as a
stereo 2- or 3-way, or a mono 4- or 5-way. It employs 4th-order
Linkwitz-Riley filter alignments to minimize phase difficulties in
the critical crossover region. e AC 23B uses XLR connectors
with active balanced Inputs and Outputs.
Simply put, a Linkwitz-Riley alignment is two cascaded 2nd-
order Butterworth filters exhibiting identical phase characteris-
tics on their low-pass and high-pass outputs. is characteristic
guarantees in-phase outputs at all frequencies. In-phase outputs
are mandatory for proper acoustic summing of common signals
from adjacent drivers in the crossover region. An added benefit of
this topology is steep 24 dB per octave rolloff slopes. A slope of
this magnitude guarantees drivers designed to produce a specific
range of frequencies, and no more, will not be driven past their
limits, thereby minimizing distortion and driver fatigue.
To further guarantee the transparent operation of the
AC 23B, adjustable Delay circuits appear on the Low & Mid
Outputs of each Channel to compensate for any physical mis-
alignment of the drivers. Time correction ensures the mechanical
phase alignment of adjacent drivers will be acoustically correct,
thus maintaining the integrity of the electrical phase alignment
of the crossover’s filters.
In 2- or 3-way stereo mode, the low outputs may be mono'ed
by moving an internal jumper. Constant directivity (CD) horn
equalization is possible with an internal modification. See the
manual for details.
See the RaneNote Linkwitz-Riley Crossovers for more infor-
mation, available at www.rane.com.
MONO 4W OR 5W: INACTIVE
4W: MID / HIGH 4W: INACTIVE4W: INACTIVE
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
100
2
4
8
6
MAXMIN
2
4
8
6
MAXMIN
2
4
8
6
MAXMIN
2
4
8
6
MAXMIN
2
4
8
6
100
80
1k
900
850
150
200
240
750
600
400
190
250
7.0k
5.8k
550
475
350
700
2.0k
2.8k
4.5k
1.0k
190
250
7k
5.8k
550
475
350
700
2.0k
2.8k
4.5k
1.0k
100
80
1k
900
850
150
200
240
750
600
400
2W: INACTIVE
ACTIVE
CROSSOVER
70 70
2W: INACTIVE 2W: LOW / HIGH 2W: LOW / HIGH2W: INACTIVE2W: INACTIVE 2W: LOW2W: LOW
LEVEL LEVEL
MUTE
LEVEL LEVEL MUTE FREQUENCYDELAY DELAYLEVEL FREQUENCY FREQUENCYLEVEL DELAY
MUTE FREQUENCY LEVEL DELAY MUTE LEVEL
AC 23B
CH 2
MASTER
CH 1
MASTER
POWERFREQUENCY
LOW MID LOW MIDHIGH HIGH
MIDMONO MASTER SUBWOOFER SUB / LOW HIGHLOW LOW / MID
3W: MID / HIGH3W: LOW / MID 3W: MID / HIGH3W: LOW / MID
5W: HIGH-MID / HIGH5W: HIGH-MID5W: MID / HIGH-MID
DATA SHEET
• Low & Mid Output Muting (3-Way)
• Input & Output Level Controls
• Fully Active Balanced XLR Inputs & Outputs
• UL/CSA/CE and 100/120/230 VAC Remote Power Supplies

AC 23B
ACTIVE CROSSOVER
Data Sheet-2
Features and Specifications
Parameter Specication Limit Units Conditions/Comments
Crossover: Alignment Linkwitz-Riley Proprietary 4th-order state-variable
..........Slopes 24 dB per Octave
..........Range (3-way) 70-1 kHz Low to Mid 41-detent continuously variable pot
..........Range (3-way) 190-7 kHz Mid to High as above
..........Range (2-way) 190-7 kHz Low to High as above
Time Delay Adjust Range Off to +2 5% ms Low & Mid Outputs only
Inputs: Impedance 20k 1 Ω
..........Maximum Level +21 1 dBu
..........Gain Range Off to +6 -0/+4 dB
Inputs: Type Active Balanced XLR Pin 2 hot per AES standards
Outputs: Type Active Balanced XLR Pin 2 hot per AES standards
..........Impedance 200 1% Ω
..........Maximum Level +20 1 dBu 600 Ω or greater
..........Gain Range Off to +12 -0/+4 dB
Band Muting Switches Yes Low & Mid Outputs only
RFI Filters Yes
Infrasonic Filter 20 Hz, 18 dB/Oct, Butterworth 3% Hz
Ultrasonic Filter 40 kHz, 18 dB/Oct, Bessel 3% Hz Linear phase
Frequency Response 20-40 kHz +0/-3 dB
THD+Noise 0.02 .01 % +4 dBu, 20-20 kHz
IM Distortion (SMPTE) 0.02 .01 % 60 Hz / 7 kHz, 4:1, +4 dBu
Signal-to-Noise Ratio 92 2 dB re +4 dBu, 20 kHz noise bandwidth
Unit: Agency Listing
..........120 VAC model Class 2 Equipment National Electrical Code
UL & CSA Class 2
..........230 VAC model VDE, SELV Safety Extra Low Voltage
CE-EMC EMC directive 89/336/EEC
CE-Safety Exempt per Art. 1, LVD 73/23/EEC
Power Supply: Agency Listing
..........120 VAC model UL File no. E88261
CSA File no. LR58948
..........230 VAC model CE-EMC EMC directive 89/336/EEC
CE-Safety LV directive 73/23/EEC
..........100 VAC model Built to JIS Japan only
Power Supply Requirement 18 VAC w/center tap 0.1 Vrms Model RS 1
Maximum Current 750 mA RMS Current from Remote Supply
Unit: Construction All Steel
..........Size 1.75" H x 19" W x 5.3" D (1U) (4.4 cm x 48.3 cm x 13.3 cm)
..........Weight 5 lb (2.3 kg)
Shipping: Size 4.25" x 20.3" x 13.75" (11.5 cm x 52 cm x 35 cm)
..........Weight 9 lb (4.1 kg)
Note: 0 dBu=0.775 Vrms

AC 23B
ACTIVE CROSSOVER
Data Sheet-3
Block Diagram

AC 23B
ACTIVE CROSSOVER
Data Sheet-4 All features & specifications subject to change without notice. DOC 107496
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 USA TEL [phone] FAX [phone] WEB www.rane.com
References
1. S.H. Linkwitz, “Active Crossover Networks for Noncoincident Drivers,” J. Audio Eng. Soc., vol. 24, pp. 2-8 (Jan/Feb 1976).
2. D. Bohn, “A Fourth-Order State-Variable Filter for Linkwitz-Riley Active Crossover Designs,” presented at the 74th
Convention of the Audio Engineering Society, New York, Oct. 9-12, 1983, preprint no. 2011.
3. D. Bohn, “Linkwitz-Riley Crossovers,” RaneNote, (1983).
4. D. Bohn, “Why Not Wye?” RaneNote, (1984).
5. D. Bohn, “Linkwitz-Riley Active Crossovers Up To 8th-Order: An Overview,” RaneNote, (1989).
Rear Panel
Available Accessories
• SC 1.7 Security Cover
Architectural Specifications
e active crossover shall contain 4th-order Linkwitz-Riley
filters. Provisions shall exist to correct for driver misalignment by
adding time delay to the low and mid frequency outputs.
e crossover frequency shall be controlled by a continuously
variable control with 41 detents to allow mechanical reference of
crossover setting.
Signal inputs and outputs shall be of active balanced design
terminated with XLR connectors. RFI, infrasonic, and ultra-
sonic filters shall be built-in.
e active crossover shall afford an input level range of Off
to +6 dB. e output level controls shall afford a level range of
from Off to +12 dB with muting capability on the low and mid
frequency outputs. e crossover shall supply two independent
channels.
e unit shall be exempt from agency safety requirements
and powered from a UL listed, CSA certified remote power
supply (120 VAC) or CE approved (230 VAC) via a rear panel
modular plug input. e unit shall be constructed entirely from
cold-rolled steel, and mount into a standard 1U EIA rack.
e unit shall be a Rane Corporation AC 23B Active Crossover.
Choosing the Right Configuration:
Mono, Dual Mono, or Stereo?
Very few systems indeed will utilize a two channel crossover
for the purpose of true stereo imaging. Discrete stereo chan-
nels which are run from the mixing board are usually used for
panning effects and/or for separate equalization of left and right
speaker stacks. Different sides of the room often require sig-
nificantly different equalization due to varying room acoustics,
dimensions, positioning of speaker stacks near walls, curtains
and the like.
Even though you may not plan to use stereo equalization
or panning effects, it is recommended that your system utilize
discrete crossover channels for each stack of speakers to ensure
flexibility and control for consistent, optimum sound qual-
ity. For example, if you plan to run a multi-stack system mono
three-way, use the AC 23B rather than the AC 22B for separate
control over each set of speakers—especially since phase align-
ment may differ with each stack requiring separate time delay
adjustments. Even with only a single system equalizer, the AC
23B can deliver the extra independent control which can make a
difference in sound throughout the listening area. If all driv-
ers are built into a single cabinet, or you are running bi-amped
monitors, then the AC 22B is the one for you.