\rMost 4 channel marine amplifiers can power between 2 and 8 speakers. If your 4 channel marine amplifier can be bridged it usualy means that it is also 2 ohm stable. You can bridge your amp to send more power to 2 speakers. You can wire your spekaers straightforward with positive to positive and negative to negative for each channel to power 4 speakers. You can power 6 speakers by doubling up and running 4 speakers in parallel off of 2 channels at a 2 ohm load and then powering the other 2 speakers off of the other two channels. Finally, you can power 8 speakers by running 2 speakers in parallel off of each channel.\r