J-INFRA subwoofer

J-INFRA subwoofer front
J-INFRA subwoofer back

J-INFRA subwoofer


Large format cardioid subwoofer

    • Components 3 x 21"
    • Dispersion Cardioid
    • SPLmax 144 dB
    • Weight 152 kg / 335 lb
    • d&b Certified Pre-Owned

    While no longer available as a new system, the J-Series lives on through d&b Remanufacturing. A Certified Pre-Owned J-Series provides the same internationally renowned sound reinforcement as a new system, with a drastically reduced carbon footprint.

    discover the benefits of Certified Pre-Owned systems

    Product description

    The J-INFRA is a cardioid infra subwoofer that can be used to supplement J-Series systems consisting of J8, J12 and J-SUB cabinets. It extends the frequency response of a J-Series system down to 27 Hz and can only be used in ground stacked configurations in conventional left/right set-ups, as well as arranged in an infra subwoofer array. It has two bass-reflex chambers containing three 21" drivers, two facing forward in one chamber that are driven from one channel of the d&b amplifier and one facing backwards driven by another amplifier channel. Through this driver set-up its cardioid dispersion pattern avoids unwanted energy behind the system and greatly reduces the reverberant field at low frequencies, providing highest accuracy in low frequency reproduction. Selecting Hypercardioid mode in the amplifier optimises the tuning of front and rear channels for a maximum rejection at the left and right sides behind the cabinet. The J-INFRA cabinet is constructed from marine plywood and has an impact and weather protected PCP (Polyurea Cabinet Protection) finish. The front and rear of the loudspeaker cabinet are protected by a rigid metal grill and the side panels incorporate eight handles. The cabinet front is fitted with four catches for securing an optional wooden lid.


    The d&b D80 amplifier is recommended to drive the J-INFRA. The d&b 30D can also be used. The 2-Way active mode for the J-INFRA requires two channels of the D80.


    Architectural specifications for detailed project planning

    Do you require architectural specifications? For a d&b system or a specific d&b Series? Here are the most important technical specifications ready for download.

    System data
    Frequency response (-5 dB standard)
    27 Hz - 60 Hz
    Max. sound pressure1
    with 30D
    with D80

    141 dB
    144 dB
    Frequency response (–5 dB 70 Hz mode)
    27 Hz - 70 Hz
    Cabinets per D80
    Loudspeaker data
    Large format cardioid subwoofer
    Nominal impedance
    3 Ω (front) / 6 Ω (rear)
    Power handling capacity front (RMS/peak 10 ms)
    1200/4800 W
    Power handling capacity rear (RMS/peak 10 ms)
    600/2400 W
    3 x 21" driver
    1 x NLT4 F
    optional 1 x EP5 or 1 x NL8
    Dimensions / weight
    Dimensions (H x W x D)
    685 x 1180 x 10402 / 1158 mm
    27.0 x 46.5 x 41.03 / 45.6"
    152 kg
    335 lb

    1 1 m, free field, SPL max peak test signal: pink noise with crest factor 4
    2 dimensions without wheels

    Similar applications
    All categories

    d&b applications

    Mobile application or fixed installation? Indoors or outdoors? Large or small? d&b provides tailored-made solutions for each and every requirement. What is more, the dedicated simulation software optimizes the planning of the system installation.
    view all applications
    Looking for a sales contact in your country?find a reseller now