If you would like to extend your home stereo system out to your backyard patio or pool area, you will likely need waterproof speakers. Most indoor speakers have paper or cardboard cones that are easily damaged by moisture so an outdoor speaker will definitely need to be waterproof. Marine speakers like these are designed for boats and they come in a variety of shapes and sizes. Since they can withstand rain and splashing in a boat they make a great choice for outside your home.
One issue that many are concerned with is the fact that most home stereo systems are 8 ohms while most mobile systems, such as those found on a boat are 4 ohms. Ohms represents the resistance in the circuit. Generally the lower the ohms the more power will flow through the system.
Fortunately, 8 ohm and 4 ohm components are virtually interchangeable in most systems with little or no chance for damage to the equipment. The only real concern is that an 8 ohm system will produce slightly less volume than a 4 ohm system. But most people can’t even tell the difference. My advice is to not worry about the ohm difference between mobile and home systems.