Self-powered 18" Studio Infrasub and 5.1 Bass Management

The ISUB-18 is a self powered professional subwoofer system. It employs bass management, hi pass filtered outputs, a sealed front firing 18" cone loudspeaker, and the INFRA dual integrator driving a 700 watt power amplifier. This provides a flat acoustical response down to 8 Hertz. Six inputs allow the combining of all the bass information on 5.1 surround programs and 2 level controls and a 10dB attenuator provide relative adjustment of the bass information from the 5 full range channels and the dedicated low frequency effect channel. 5 hi pass line level filtered outputs are provided for the upper range loudspeakers and a line level INFRA output is provided for additional INFRA bass speakers. Internally set Dynamic Filter protection maintains undistorted audio reproduction under accidental overload conditions. A remote indicator module is provided and may be placed in a convenient visible location to indicate the dynamic filter protection threshold has been reached.

INFRA? TECHNOLOGY DESCRIPTION:
The INFRA driver is operated below resonance and flattened with an electrical boosting circuit, the INFRA dual integrator. Operating below resonance the INFRA system exhibits predictable, uniform response and reproduces each note with the same emphasis, reducing the influence of the resonances found in conventional above resonance bass systems. In addition, the use of a low pass filter is eliminated (and with it the associated long variable delay) and replaced with the INFRA dual integrator with its short uniform delay. Upon close listening, it is clear that the impression of power and impact is greater with an INFRA system when compared to conventional bass systems. This is true even when the two systems will measure the exact same Sound Pressure Level on a calibrated SPL meter. This is because the INFRA subwoofer maintains the bass energy in a tight packet, aligned with the upper range signal, providing a greater body impact and a seamless musical connection with the main loudspeakers. Objectively, the INFRA system exhibits superior frequency and phase response.

Output Configuration

• 5 Balanced hi-pass XLR male line level
• 1 Balanced INFRA XLR male line level
• HI-Pass Filter Frequency: - 3 dB @ 130 Hz/-6 dB @ 95 Hz
  Hi Pass Filter Slope: 12 dB/octave
  Hi Pass Gain: Unity
  INFRA Output Mode: Sum of all inputs
  INFRA Module: 8 Hz dual integrator

  INFRA Frequency Response:

  • ±3 dB 8 Hz to 95 Hz (2p Steradians)
  • INFRA system -6 dB frequency 95 Hz (not adjustable)
  • INFRA Level Control: Adjustable level control and 10 dB attenuator on Input F
    INFRA Cutoff Frequency: Switchable 8 Hz or 20 Hz

    INFRA Overload Protection:

    • Preset threshold Dynamic Filter circuitry
    • RTI: Remote Threshold Indictor
    • Threshold exceeded indication red LED
    • Amplifier Output Power: 700 Watts continuous sine wave
      Enclosure: 3/4" MDF
      Finish: Black textured finish or optional high gloss automotive finish
      Grille: Black nylon cloth on frame

      Dimensions:

      • 22"h x 21"w x 18"d
      • 55.8cm x 53.3cm x 45.7cm
      • Weight: 75lb. - 34 kg