The JBL's CONTROL 28-1 indoor/outdoor monitors have weather-protected electronics, natural and strong representations of the frequency range, white 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 they can handle 240W of programming material at 8 Ohms. You can blast these speakers rather loudly, too, with an SPL of 112 dB, and their cone design offers a pleasant listening experience on and off-axis. Their PEI diaphragms also provide a smooth high-frequency response.