Two-Way Passive Loudspeaker with 12" Woofer, 1.75" Compression Driver, and 600-Watt Power Capacity. Mackie's C300z monitor is an unpowered loudspeaker with character and power. For maximum sound dispersal, the C300z sports components from the ubiquitous SRM450 with custom design and tuning by Eastern Acoustic Works. What this means to you is that your audience hears you loud and - most importantly - clear.