The JBL's CONTROL 23-1 indoor/outdoor monitors features weather-protected electronics, natural and strong representations of the frequency range, black enclosures, and JBL's patented InvisiBall mounting gear. This device has a secret access port beneath its logo badge that allows you to add the speakers. This powered speaker has a built-in multi-tap transformer for operation on distributed speaker lines and can handle 100W of programming material at 8 Ohms. You can blast these speakers rather loudly, too, with an SPL of 103 dB, and its cone design offers a pleasant listening experience in both on- and off-axis settings. Their PEI diaphragms also produce a smooth high-frequency response.