In the meantime, here are some general specifications commonly found in 15-inch passive speakers:
Woofer Size: 15 inches
Frequency Response: Typically ranges from 50 Hz to 20 kHz
Power Handling: Ranges between 400 W to 600 W continuous power
Sensitivity: Approximately 96 dB to 100 dB (1 W at 1 m)
Impedance: Commonly 8 ohms
Maximum SPL: Around 125 dB to 130 dB
Coverage Pattern: Varies, often around 70° to 90° horizontal and 50° to 70° vertical
Enclosure Material: Typically made from plywood or MDF with a protective finish
Connectors: Standard connectors include Speakon or 1/4" jacks
 
These specifications are general and can vary between different models and manufacturers. Once you provide the exact model details, I can offer more precise information.