JBL 15? 15WP550 – 550 Watts RMS – 8 Ohm Woofer. 1 x Speaker 15 WP 550. 1 x Technical Brochure. The new 15 JBL 15WP550 PRO – 550 Watts RMS Woofer has 8 Ohms impedance and is suitable for use in professional or automotive sound. It has high sensitivity, at 97dB, providing high performance, as well as excellent cost benefit.