Jbl MS6510-X2-MA6004 MS6510 Speakers & MA6004 AMP 4-Channel Amplifiers. Fully marinized circuit boards to keep salt and corrosion away from the critic Onboard 12dB electronic crossovers to provide tuning options for systems of any size. Variable bass- Low-profile heatsink allows for installation in tight spaces. Large-gauge barrier strips allow easy MA6004: 145W at 2 ohms, 60W RMS x 4 channels at 4 ohms and less than or equal to 1% THD + N. Overall MS6510 6-.5" Dual Cone Marine Speaker - (Pair) White JBL Marine Series Speakers are ready to take on