XL4 Technical Specification.
 
Input Impedance  Mic 2K Balanced

    Line   20K Balanced

Input Gain ( all faders at 0dB )Mic   Continuously variable from  + 15dB to + 70dB

    Mic + Pad  Continuously variable from - 5dB to + 50dB

    Channel  Continuously variable from Line Input  - 20dB to + 20dB

    All other Line Inputs 0dB

Maximum Input Level  Mic  + 6dBu

    Mic + Pad  + 26dBu

    Channel Line Input + 26dBu
 
    All other Line Inputs +21dBu

CMR at 1kHz   Mic ( gain + 60dB ) > 70dB

    Mic + Pad
    ( gain + 40dB )  > 50dB

    Line   > 60dB

Frequency Response
( 20 to 20kHz )  Mic to Mix
    ( gain + 60dB )  + 0dB to - 1dB

    Line to Mix   + 0dB to - 1dB

Noise ( 20 to 20kHz )  Mic EIN ref. 150 Ohms
    ( gain + 60dB )  - 129dBu

    Line EIN ref. 150 Ohms
    ( gain + 10dB )  - 100dBu

System Noise ( 20 to 20kHz ) Summing Noise
    ( 12 channels routed with faders down )  - 86dB

    Line to Mix Noise
    ( 12 channels routed at 0dB, pan centre ) - 81dB

Summing Noise
    ( 48 channels routed with faders down ) - 80dB

    Line to Mix Noise
    ( 48 channels routed at 0dB, pan centre ) - 75dB

Distortion at 1kHz  Mic to Mix ( + 60dB gain, 0dBu output ) < 0.03%

    Line to Mix ( 0dBu ) < 0.03%

Crosstalk at 1 kHz  Channel to Channel < - 100dB

    Mix to Mix  < - 90dB

    Channel to Mix < - 90dB

    Maximum Fader
    attenuation  > 90dB

Output Impedance  All Line Outputs 50 Ohms Balanced Source to drive > 600 Ohms

    Headphones  To drive > 8 Ohms Unbalanced

    Comms ( Bi -
    directional )  600 Ohms Nominal Unbalanced

Maximum Output Level All Line Outputs + 21dBu

    Headphones  + 21dBu ( 8W into 8 Ohms )

    Comms( Bi - directional )  - 10dBu
 
Nominal Signal Level  Mic   - 70dBu to + 5dBu

    Channel
    Line Inputs  - 20dBu to +5dBu

    All other Line
    Inputs and Outputs 0dBu

    Headphones  + 10dBu

    Comms  - 20dBu

    Comms and
    Talk Mic  - 50dBu to - 20dBu ( auto gain )
 
Headroom at all stages Comms, Talk and Headphone > 10dB

    All other signals > 20dB

Metering Type   20 led peak reading

    Range   - 36dBu to + 21dBu

    Colour Green  Up to + 9dBu Normal signal

    Colour Yellow  + 12dBu to + 15dBu High signal

    Colour Red  Over + 18dBu Signal Too High
 
    Quantity  77 ( Monitoring all main
       inputs and outputs )

Equaliser   Low pass slope 12dB / Oct.

    Low pass frequency Continuously variable
       - 3dB point from 1K to 40K

    Hi pass slope  12dB / Oct.

    Hi pass frequency Continuously variable
       - 3dB point from 10Hz to 400Hz

    Treble Gain  Continuously variable
       + 15 dB to - 15 dB
       Centre detent = 0dB

    Treble Shelving Freq. Continuously variable
        3dB point from 1K to 20K
 
    Treble Bell Freq. Continuously variable
       centre from 1K to 20K

    Treble Bell   Continuously variable
    Bandwidth  0.1 Oct. to 2 Oct.
       Centre detent = 0.5 Oct.

    Hi Mid Gain  Continuously variable
       + 15 dB to - 15 dB
       Centre detent = 0dB
 
    Hi Mid Freq.  Continuously variable
       centre from 400Hz to 8K

    Hi Mid Bandwidth Continuously variable
       0.1 Oct. to 2 Oct.
       Centre detent = 0.5 Oct.

    Lo Mid Gain  Continuously variable
       + 15 dB to - 15 dB
       Centre detent = 0dB

    Lo Mid Freq.  Continuously variable
       centre from 100Hz to 2K

    Lo Mid Bandwidth Continuously variable
       0.1 Oct. to 2 Oct.
       Centre detent = 0.5 Oct.

    Bass Gain  Continuously variable
       + 15 dB to - 15 dB
       Centre detent = 0dB

    Bass Shelving Freq. Continuously variable
       3dB point from 20Hz to 400Hz
 
    Bass Bell Freq. Continuously variable
       centre from 20Hz to 400Hz

Dimensions  Width 2176 mm
       Depth 1120 mm
       Height 420 mm

Shipping Weight  420kg