Adding one speaker....

[Kramfam]

I have an Infinity 4 speaker system that came with the boat....2 speakers up front, 2 speaker in back and nothing in the middle. It sounds great when anchored but I can barely hear it while underway (I'm driving) and the guests are rockin'. I'm looking to add just one speaker on the aisle side of the steering console. Is it as simple as just wiring it in, or will that substantially reduce the power to the other 4 speakers?

I'm totally clueless when it comes to stereos.

[Xscash]

When it comes to sound systems its the ohms rating that matters. All speakers have resistance in a specific ohm value. The stereo has a max capacity of so many ohms. when you add a speaker, depending on the wiring method, you will raise or lower ohms. if you raise them you lower power out put and divide it by both speakers. if you lower you increase power output and still divide by both speakers. Lowering is ideal so you do not lose any power from the existing speaker.....BUT.....there is a minimum rating that the radio can handle. if you go below that rating it will blow the radio amp. best bet is to add a tiny waterproof amp behind the radio and run an extra speaker or 2 from that. you can find small waterproof amps for very cheap money and most will draw so little current you can use the existing wiring in the console.
http://www.ebay.com/itm/Pyle-Waterproof ... SwGIRXYLcH
something like this will be perfect
OR....if your current speakers are 8ohm and you buy another 8 ohm speaker then wire it to 4ohms, you should be safe. most radios will handle a 4 ohm load.
Rick