To successfully install a set of outdoor speakers there are a couple of key things you need to know to make things go smoothly.
First, work out the best position for your speakers. Contrary to popular belief there is no real 'best' position. The best position is where they look the best aesthetically in your outdoor area.
Use the following chart to figure our which cable is right for you:
Next, work out the approximate distance from the amplification source to the desired speaker location. This is important in working out which gauge of speaker cable to purchase. Too small and you will be driving your amplifier too hard and too big and you will be spending money unnecessarily
Although somewhat important, from a sound perspective, there are generally no walls for the sound to reflect off like there are in a theatre room. It is better to think about where they will look best in your area rather than worry about sound and reflections. Where they are positioned will also be determined by things like brickwork / siding and your ability to pass cables through these barriers.
Once the desired location has been selected the next step is to work out how you are going to mount the speakers. The most common method of mounting these speakers is in a horizontal method as pictured below. You can of course mount them vertically as well depending on the location without any effect on the speakers.
After you have mounted the bracket the next step is to get the cable through the wall and to the speaker. The ends of the cable should be terminated directly into the speaker without any further connections. As the cable is outdoors it will corrode over time.
One way to avoid this is to 'tin' the ends of the cable when you strip the outer coating off exposing the copper inside. This is simply a coating of solder applied with a soldering iron and some solder. This will give you a connection that will last longer in an outdoor environment and provide a higher quality of join.
Once the ends of the cable are coated the next step is to insert the cables into the holes. It is important at this stage to make sure that the negative and positive are connected correctly from the amplifier.
The cable usually has one side that is marked with either some form of writing or a stripe. The easiest way to remember which side is which is to make the stripe side the negative (or black side) and the non marked side the positive (or red side).
After the cables are inserted the next step is to turn on the amplification source and test the speakers to make sure they are working correctly.
Resist the temptation to turn them up loud at this stage as you will most likely damage the speakers.
Speakers need to be 'run in' at low operating levels for a while before turning them up too loud. By running the speakers at a moderate level for a few hours after they are installed you will help prolong the life of them.