The C300 uses the same basic transducers as the active SRM450 -- with two differences. The C300's 1.75-inch high frequency compression driver uses a composite mylar diaphragm; the 12-inch low frequency transducer incorporates a 3-inch Inside/Outside temperature- resistant voice coil. Both of these compensate for the fact that the speaker system must be able to handle a wide range of external power inputs (including Mackie's mega-powered PPM808S or PPM808M). The C300 uses the same studio-quality horn assembly with multi-cell aperture horn throat and large format exponential/conical high-frequency horn mouth for superb dispersion. This means everyone in your audience hears clearly ? not just the people in the middle between the speakers. And like the SRM450, the C300 has the same asymmetrical trapezoidal cabinet for minimum internal resonance and the ability to recline for floor monitor use. The C300 is a weight-balanced enclosure with dual side handles and a top handle, built-in pole mount and ten built-in hanging points. But instead of internal amplification, the C300 has a Low-Impedance Compensated Crossover (LICC) with full built-in transducer protection and Speakon® inputs that just beg to be energized. ? Portable Precision Passive loudspeaker with 1.75" HF compression driver and 12" LF transducer ? HF compression driver mounted on a multi-celled aperture, with a constant directivity horn for room-wide 90° x 45° dispersion ...