The LC4 ceiling speaker series can be used in a variety of ceiling environments. They can achieve excellent voice and music playback effects in indoor public broadcasting applications. The new CosCone cell technology used in this series enables small speakers to provide excellent sound quality. It ensures excellent frequency response, reduces the directionality of high frequencies, and allows all frequencies to spread evenly. The same area can be covered with fewer speakers, and when the listener walks from one speaker to another, there is no obvious change in sound pressure. The lc4-ucxxe ceiling speaker is lightweight and compact, and adopts a concealment front net cover of neutral design. This series provides three speakers, they have 6 W, 12 W and 24 W input power and the open Angle of the same width, ensure excellent frequency response, and the all important frequency can be evenly spread, so as to provide clear voice and music. The LC4 series also includes a base case and metal flameproof cover. All Bosch speakers are certified to meet IEC 268-5 power handling capacity (PHC) standards and can operate continuously for 100 hours at rated power. Bosch has also conducted simulated acoustic feedback exposure tests to ensure they can withstand twice the rated power in a short period of time. This ensures high reliability of the speaker under extreme conditions, improves customer satisfaction, extends service life, and significantly reduces the probability of failure or performance degradation. LC4 series are certified by UL1480F for fire alarm and/or emergency communication systems. Security in accordance with EN 60065 standard waterproof and dustproof emergency * * EN 60529 IP 21 standards in accordance with the requirements of BS 5839 part 8 * EN 54 ‑ 24 standard has LC4 ‑ CBB bottom box or LC4 ‑ MFD flameproof enclosure area certification European CE CPD UL installation/configuration LC4 series installation is very simple. Each speaker comes with a perforated template and can be fixed to a ceiling up to 50mm (2in) thick with two integral screw clips. It can be connected through the screw connector in the box body. This screw terminal block on the input and output terminals of the same potential interface, independent into a screw block. The 70 V and 100 V power taps allow the user to select full power, 1/2 power, 1/4 power, 1/8 power and 8 ohm. The front selector of the speaker simplifies the power setting.