Rane AC 22, AC 22B User Manual

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DATA SHEET

General Description

The Rane AC 22 and AC 22B Active Crossovers are Stereo 2-Way with mono subwoofer option, or can be used as a Mono 3-Way. They employ state-variable 4th-order Linkwitz-Riley filter alignments to minimize phase difficulties in the critical crossover region. The model AC 22 utilizes ¼" TRS connectors with balanced/unbalanced inputs and unbalanced outputs. The new AC 22B 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

AC 22 & AC 22B

ACTIVE CROSSOVERS

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 22 and AC 22B, adjustable Delay circuits appear on the Low (& Mid when used in 3-Way mode) 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. The Low Delay circuit may be internally transplanted to the High Output when neccessary. CD horn equalization is also possible with an internal modification.

See RaneNote 107 for more information regarding Linkwitz-Riley designs.

Features

• Stereo 2-Way or Mono 3-Way

• Linkwitz-Riley Alignment with 24 dB per Octave Slopes

• Adjustable Delays

• Mono Subwoofer Switch and Output

• Infrasonic, Ultrasonic, and RFI Filters

• Low Output Muting (2-Way)

• Input & Output Level Controls

• UL/CSA/CE and 100/120/230 VAC Remote Power Supplies

AC 22 Features

• ¼" TRS Inputs & ¼" TS Outputs

• Active Balanced/Unbalanced Inputs & Unbalanced Outputs

AC 22B Features

• XLR Inputs & Outputs

• Fully Active Balanced Inputs & Outputs

Data Sheet-1

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AC 22 & AC 22B

ACTIVE CROSSOVERS

Parameter Specification Limit Units Conditions/Comments

Crossover: Alignment Linkwitz-Riley Proprietary 4th-order state-variable

..........Slopes 24 dB/octave

..........Range 70-3.6 kHz Low to High 41-detent continuously variable pot

Time Delay Adjust Range Off to +2 5% ms Low & Mid Outputs AC 22 Inputs: Type Active Balanced/Unbalanced

..........Connectors ¼" TRS

..........Impedance 20k 1% ohms

..........Maximum Level +21 1 dBu

..........Gain Range Off to +6 -0/+4 dB

AC 22 Outputs: Type 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 22B Inputs: Type Active Balanced

..........Connectors XLR pin 2 hot per AES standards

..........Impedance 20k 1% ohms

..........Maximum Level 21 1 dBu

..........Gain Range Off to +6 -0/+4 dB

AC 22B 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 RFI Filters Yes Infrasonic Filter 20 Hz, 18 dB/oct., Butterworth 3% Hz Ultrasonic Filter (AC 22) 40 kHz, 6 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 Exempt Class 2 equipment

..........230 VAC model CE-EMC EMC directive 89/336/EEC

CE-Safety Exempt per Art. 1, LVD 73/23/EEC Power Supply: Agency Listing Class 2 Equipment

..........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 RS 1 (see data sheet)

..........Maximum Current 160 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 4 lb (3 kg)

Shipping: Size 4.25" x 20.3" x 13.75" (11 cm x 52 cm x 35 cm)

..........Weight 8 lb (5 kg)

Note: 0 dBu=0.775 Vrms

Data Sheet-2

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AC 22 Block Diagram

AC 22 & AC 22B

ACTIVE CROSSOVERS

AC 22B Block Diagram

Data Sheet-3

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AC 22 & AC 22B

ACTIVE CROSSOVERS

Rear Panels

Choosing the Right Configuration: Mono, TwoChannel 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 equalization 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 listening 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.

Available Accessories

• SC 1.7 Security Cover

Architectural Specifications

The active crossover shall contain 4th-order LinkwitzRiley filters. Provisions shall exist to correct for driver misalignment by means of adding time delay to the low frequency outputs.

The crossover frequency shall be controlled by a continuously 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) connectors for the AC 22, and active balanced terminated with XLR connectors for the AC 22B. Signal outputs shall be unbalanced type terminated in ¼" TS connectors for the AC 22, and active balanced design terminated with XLR connectors for the AC 22B. RFI filters shall be provided. 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 for the AC 22B) with muting capability on the low 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 input modular plug. 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 22 or AC 22B Active Crossover.

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).

Data Sheet-4

All features & specifications subject to change without notice. DOC 103033 PN 07531 9-98