Mechanical Horn Coupling and Mounting Procedure
The Ahuja AU-50XT driver unit is engineered for rigid mechanical integration with industrial Public Address (PA) reflex horns and acoustic trumpets. It utilizes an industry-standard 1-3/8” - 18TPI (Throat Couple No. 1) threaded coupling. The acoustic head flange is manufactured from die-cast aluminium, providing mechanical stability and structural integrity during high-torque thread engagement.
Before threading the driver unit onto the reflex horn, ensure that the male threads of the driver flange and female throat threads of the horn are clean and free of debris. Carefully align the driver unit perpendicular to the horn throat and rotate clockwise until seated firmly. When properly mounted on an appropriate reflex horn assembly, the driver achieves an IP66 ingress protection rating in accordance with standard EN 60529, protecting the internal assembly against particulate dust and high-pressure water jets.
Dimensions and Structural Load Considerations
Site engineers and system integrators must account for the mechanical load when designing bracketry, poles, or wall mounts. The AU-50XT features an outer diameter of 150 mm, an overall height of 143 mm (ø150 x H143 mm), and a net unit weight of 2.47 kg. Mounting brackets and hardware must be rated to support the combined static and dynamic wind load of both the 2.47 kg driver unit and the attached horn flare in outdoor installations.
100V Line Power Tap Selection and Wiring
The AU-50XT includes a built-in 100V line matching transformer designed for distributed high-impedance Public Address sound systems. Power tap adjustment is executed directly via a rotary switch positioned at the rear housing of the unit, eliminating the need for internal transformer rewiring or soldering during field setup.
| Switch Setting (Power Tap) | Input Impedance (100V Line) | Continuous Power (RMS) | Max Power Handling |
|---|---|---|---|
| 50W | 200 Ω | 50W RMS | 70W Max |
| 40W | 250 Ω | 40W RMS | 70W Max |
| 20W | 500 Ω | 20W RMS | 70W Max |
| 10W | 1000 Ω (1 kΩ) | 10W RMS | 70W Max |
| 5W | 2000 Ω (2 kΩ) | 5W RMS | 70W Max |
When deploying multiple driver units across a constant-voltage 100V speaker distribution line, total system load is calculated by summing the wattages selected via the rear rotary switch across all parallel-connected units. The aggregate power draw must not exceed the continuous RMS output rating of the upstream 100V PA booster or mixer amplifier.
Thermal and Environmental Installation Requirements
The voice coil in the AU-50XT is precision-wound on an aluminium bobbin designed for efficient thermal dissipation during continuous high-power acoustic projection. The driver supports an operating temperature range of -30°C to +70°C, making it suitable for unconditioned industrial plants, perimeter fencing, and outdoor structural mountings. Ensure that continuous signal driving remains within the 50W RMS rating (70W maximum) within the operational frequency band of 160 Hz to 7,000 Hz to prevent mechanical or thermal voice coil over-excursion.
