Rane AC 23B User manual

AC 23 & AC 23B
ACTIVE CROSSOVERS
Data Sheet-1
AC 23 Features
• ¼" TRS Inputs & ¼" TS Outputs
• Active Balanced/Unbalanced Inputs & Unbalanced Outputs
AC 23B Features
• XLR Inputs & Outputs
• Fully Active Balanced Inputs & Outputs
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
• Low & Mid Output Muting (3-Way)
• Input & Output Level Controls
• UL/CSA/CE and 100/120/230 VAC Remote Power Supplies
General Description
The Rane AC 23 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. The AC 23 uses
¼" TRS connectors with balanced/unbalanced Inputs and
unbalanced Outputs. The 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
characteristics on their low-pass and high-pass outputs. This
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 23, adjustable Delay circuits appear on the Low & Mid
Outputs of each Channel to compensate for any physical
misalignment 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. CD horn
equalization is now possible with an internal modification.
Time Delay can also be internally transplanted to the Mid and
High Outputs if desired.
See RaneNote 107 for more information regarding
Linkwitz-Riley designs.
DATA SHEET

AC 23 & AC 23B
ACTIVE CROSSOVERS
Data Sheet-2
Parameter Specification Limit Units Conditions/Comments
Crossover: Alignment Linkwitz-Riley Proprietary 4th-order state-variable
..........Slopes 24 dB/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 ohms
..........Maximum Level +21 1 dBu
..........Gain Range Off to +6 -0/+4 dB
AC 23 Inputs: TypeActive Balanced/Unbalanced
..........Connectors: AC 23 ¼" TRS
AC 23B Inputs: Type:Active Balanced
..........Connectors: AC 23B XLR Pin 2 hot per AES standards
AC 23 Outputs: Type Floating Active Unbalanced
..........Connectors ¼" TS
..........Impedance 100 1% ohms
..........Maximum Level +20 1 dBu 600 ohms or greater
..........Gain Range Off to +6 -0/+4 dB
AC 23B Outputs: Type Active Balanced
..........Connectors XLR Pin 2 hot per AES standards
..........Impedance 200 1% ohms
..........Maximum Level +20 1 dBu 600 ohms 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 Requirment 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 23 & AC 23B
ACTIVE CROSSOVERS
Data Sheet-3
Block Diagram AC 23B
Block Diagram AC 23
See Operating Manual for Hook-Up and Configuration Options

AC 23 & AC 23B
ACTIVE CROSSOVERS
Data Sheet-4 All features & specifications subject to change without notice. DOC 103044 PN 07560 6-99
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 TEL [phone] FAX [phone] WEB http://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,”Rane Note 107, (1983).
4. D. Bohn, “Why Not Wye?”Rane Note 109, (1984).
5. D. Bohn, “Overload Characteristics of State-Variable Crossovers,”Rane Note 112, (1985).
6. D. Bohn, “Linkwitz-Riley Active Crossovers Up To 8th-Order: An Overview,”Rane Note 119, (1989).
Rear Panels
Available Accessories
• SC 1.7 Security Cover
Architectural Specifications
The 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.
The crossover frequency shall be controlled by a continu-
ously variable control with 41 detents to allow mechanical
reference of crossover setting.
Signal inputs shall be active balanced/unbalanced designs
terminated with ¼" TRS (tip-ring-sleeve) or XLR connectors.
Signal outputs shall be unbalanced terminated in ¼" TS
connectors or active balanced design terminated with XLR
connectors. RFI, infrasonic, and ultrasonic filters shall be
built-in.
The active crossover shall afford an input level range of
Off to +6 dB. The output level controls shall afford a level
range of from Off to +6 dB (+12 dB AC 23B balanced) with
muting capability on the low and mid frequency outputs. The
crossover shall supply two independent channels.
The 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. The unit shall be constructed
entirely from cold-rolled steel, and mount into a standard 1U
EIA rack.
The unit shall be a Rane Corporation AC 23 or 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 channels which are run from the mixing board are
usually used for panning effects and/or for separate equaliza-
tion of left and right speaker stacks. Different sides of the
room often require significantly 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
quality. For example, if you plan to run a multi-stack system
mono three-way, use the AC 23 rather than the AC 22 for
separate control over each set of speakers—especially since
phase alignment may differ with each stack requiring separate
time delay adjustments. Even with only a single system
equalizer, the AC 23 can deliver the extra independent control
which can make a difference in sound throughout the listen-
ing area. If all drivers are built into a single cabinet, or you
are running bi-amped monitors, then the AC 22 is the one for
you.