The Ahuja NBA-15 is an ultra-portable 12W public address amplifier engineered for rapid commissioning across mobile applications such as instructional classrooms, tour guiding, yoga sessions, and training presentations. Proper physical deployment and signal routing ensure low distortion and optimal acoustic performance across its 80 Hz to 12,000 Hz frequency response range.
Power Infrastructure and Battery Commissioning
Before operational deployment, the internal 3.7V, 2000mAh rechargeable lithium-ion battery must be fully charged using the supplied power supply adapter. Connect the AC adapter to an electrical supply rated at 100–240V AC (50/60 Hz). Insert the adapter's DC output lead (delivering 5V DC, 750mA) into the dedicated charging port on the amplifier housing. Monitor the integrated low-battery LED indicator to verify operational readiness during pre-deployment checks.
Wearable Mounting Configurations
With an ultra-compact footprint measuring 86 mm (W) × 98 mm (H) × 44 mm (D) and an overall weight of approximately 0.34 kg (including the internal battery), the amplifier unit is designed for mobile hands-free operation. Users can deploy the system in two primary configurations:
- Waist-Worn Setup: Secure the amplifier around the operator's waist using the adjustable strap, positioning the internal 4Ω speaker driver facing outward into the coverage area.
- Shoulder-Slung Setup: Lengthen the strap to hang the unit across the shoulder, ensuring the speaker grille remains unobstructed by heavy clothing to preserve high-frequency acoustic dispersion.
Headband Microphone Connection and Capsule Positioning
Connect the included headband microphone lead to the Ø 3.5 mm microphone input jack (Mic-1 rated at 1.0mV input sensitivity). Position the headband securely over the head so that the condenser transducer sits comfortably near the user's temple. Position the flexible gooseneck to locate the cardioid condenser capsule approximately 2 to 3 cm from the corner of the mouth. Because cardioid polar patterns exhibit directional sensitivity, aim the capsule directly at the mouth while keeping the physical speaker enclosure oriented away from the microphone to eliminate acoustic feedback loops.
Auxiliary Line Input Integration
For applications requiring background music or pre-recorded audio alongside vocal projection, connect an external media source (such as an MP3 player, CD player, or DVD unit) into the dedicated 3.5 mm Line input socket. The line channel is matched for 250mV input sensitivity, allowing seamless signal amplification without exceeding the amplifier's 12W maximum low-distortion threshold.
Technical Deployment Parameters
| Parameter | Specification |
|---|---|
| Maximum Power Output | 12W Max (Low-Distortion Circuitry) |
| Speaker Impedance | 4Ω |
| Audio Frequency Bandwidth | 80 Hz – 12,000 Hz |
| Microphone Port Specification | Ø 3.5 mm Socket / 1.0 mV Sensitivity (Condenser Cardioid) |
| Line-In Port Specification | Ø 3.5 mm Socket / 250 mV Sensitivity |
| Internal Power Supply | 3.7V, 2000mAh Rechargeable Lithium-ion Battery |
| Charging Power Requirements | 100–240V AC 50/60Hz Input; 5V DC, 750mA Output |
| Unit Dimensions & Weight | 86 mm (W) × 98 mm (H) × 44 mm (D); ~0.34 kg |
