Systems ListZOD AudioM.A.U.L.

ManufactureZOD Audio
System typeHorn
DriverRockford Fosgate T3S2-19
Driver Size18 "
Number of drivers4
Internal volume31 ft3
External volume38.35 ft3
Dimentions (Width × Height × Depth)47 " × 30 " × 47 "
Weight550 lbs
Native Tuning Frequency15 Hz
Power18000 W
Aprox. Price$10000 USD


This unusual subwoofer is a custom one off design for my own dedicated sound reinforcement system. It is a fixed install where a pair will be operating as the dedicated SW channel in a large and lossy space of >14,000 cubic feet. The design is made to fit a specific location, placement and set of performance goals. The desired goals include:Low distortion, low compression, abuse tolerance, extreme amounts of deep bass headroom with ease, even in a large space and a useful bandwidth of 15-100Hz. The resulting design is extremely large, dense, heavy, complicated and expensive as these were the compromises chosen in order to achieve the desired performance level. 

The measured results are quite strong and indicate that the system achieved most of the desired goals well. The available headroom, power handling and distortion performance over the critical 15-80Hz bandwidth are remarkable indeed. Despite being a very large 47x47x30” the system is actually quite output dense relative to its size and deep bass extension. 

For fun here are a set of realistic “Manufacturers” specifications based on the measurements. Marketing department specs would be quite a bit different (For the better) by doing things like rounding up to the nearest decibel, using aggressive smoothing on the measurements, using DSP to flatten and extend the response, quoting calculated peak SPL instead of measured, etc... 

M.A.U.L. High performance extended low frequency subwoofer for large venue, outdoor, fixed installation
Specifications: (Based on outdoor ground plane measurements with ZERO smoothing and ZERO signal processing applied)
Drivers: 4x 19” extended linear throw with neodymium push/pull motor and 5” edge wind voice coil 
Cabinet: Series loaded, opposed firing, 6th order quasi bandpass horn. 
Dimensions: 47x47x30” / 119.4x119.4x76.2cm
Weight: 550lbs (250kg)
Impedance: 4ohms mono (Min Z=4ohms@15Hz)
Recommended Amplifier Power: 1-20,000 watts (The largest currently available touring amplifiers may be used without need for limiting.)
Frequency Response: 14.5-128Hz+/-8dB (Measured, raw response, 2m outdoor ground plane, no smoothing, no processing)
Recommended Operational Bandwidth: 12-90Hz(Highpass may be used below 15Hz, but not required, Lowpass 100Hz or lower @24dB octave or greater)
Sensitivity: 100dB SPL(Average SPL from 15-105Hz, 2V input, 1m ground plane)
Sensitivity Max: 107dB SPL@89Hz (2V input, 1m ground plane)
Sensitivity Min: 92dB SPL@14Hz (2V input, 1m ground plane)
Maximum SPL Long Term: 139dB SPL@89Hz (REF to 1m full space, measured 2m half space)
Deep Bass SPL Long Term: 120dB SPL@14Hz (REF to 1m full space, measured 2m half space)
Short Term Peak SPL: 147dB SPL@80Hz (Peak output, REF to 1m full space, measured 6.5 cycle shaped Hann burst,4m half space)
Deep Bass Short Term Peak SPL: 129dB SPL@16Hz (Peak output, REF to 1m full space, measured 6.5 cycle shaped Hann burst,4m half space)