JBL ASC24 2x4-Channel Crossover and Signal Processor

May only be bought as part of a complete system

The ASC24 provides two analog channels of two-way signal processing for Array Series loudspeakers. To assure optimum acoustic performance, careful consideration was given to the overall circuit topology. The ASC24 achieves a very low noise floor, smooth amplitude response, and maximum safe dynamic range. Use of low noise components in the active signal path guarantees quiet performance for any application. 24dB per octave Linkwitz-Riley type crossover filters with phase compensation, equalization and limiting for each output combine to provide outstanding sonic quality. A 30Hz high-pass filter protects against infrasonic (subsonic) damage. The ASC24 utilizes mid-filter type limiting circuitry. The limiting occurs between two lesser-sloped crossover stages to reduce band spreading and to produce a smoother response around the crossover point during limiting. To reduce noise, the limiter is placed in a side-chain to the audio signal, removing it from the direct audio circuit during lower operational levels.

Features:

• Two-Channel Analog Controller: Configured for Array Series Loudspeakers
• Complete Signal Processing:
  • Crossover Filters
  • Phase Compensation
  • CD Horn Equalization
  • Mid-Filter Type Limiters with Switch Selectable Threshold
• Convenient Controls: Level trim controls and channel mutes located on the front panel for quick adjustment.

Specifications:

• Speaker System Compatibility: Array Series: 4890, 4891, 4892, 4892-90, 4894, 4894-90
• Configuration: 2 channels by 2-way outputs
• INPUTS & OUTPUTS:
  • Inputs: 2 channels, Max level +20dBu, 10KΩ impedance, Pin 2+
  • Outputs: 4 bands, Max level +20dBu into 600Ω impedance, Pin 2+
  • Output Impedance: 47Ω
• CONTROLS & INDICATORS:
  • Front Panel Controls: ±6dB trim control on front panel
  • Mute for each output band
  • Rear Panel Controls: Limiter threshold for each output band, 1dB steps, via rotary switches
  • AC voltage selectable
  • Displays: Band-type, mute, signal present, limiter function
• PERFORMANCE:
  • Dynamic Range: >110dB
  • Total Harmonic Distortion: <0.005% typical, 0.1% maximum
  • Output Channel Mute: Each output, auto on (4 sec) power up and down
  • Nominal Gain: 0dB (Unity Gain)
  • Crossover: 24dB/oct Linkwitz-Riley, 1kHz
  • Limiters:
    • User-adjustable threshold in 1dB steps via switches on back panel (from –10dB to +5dBu).
    • Mid-filter type
    • Limiter ratio >20:1
  • Frequency Response: 30 Hz to 20 kHz
  • High-Pass Filter: 30Hz
• PHYSICAL:
  • Power Requirements: Selectable 120V or 240V, +10%/–20% 50/60 Hz
  • Dimensions (H x W x D): 44.5 x 483 x 292 mm (1.75 x 19 x 11.5 in)
  • Weight: 4 kg (8.8 lbs.)