Chances are, if you are mounting speakers or a television in a conventional home, you will be installing the mounts using screws, which is fine, provided that your walls and ceilings are made of wood and are at least one inch thick. Otherwise, you are going to need some additional support. With the typical walls being made of sheetrock (AKA drywall,) this material is just not strong enough to securely hold a weight bearing screw on its own without taking some extra measures for security.
If you are going to go to the trouble of marking and drilling holes, then screwing each face plate to the wall and then attaching each speaker, you will want to get it right the first time. When too much weight pulls excessively on anything that screws are holding via sheetrock, the screw will eventually rip from the wall, and probably taking a hefty chunk of the sheetrock with it. This means don’t even try wall anchors, as they are only suitable for supporting a modest amount of weight. Toggle bolts are somewhat OK, but, like wall anchors, they max out at certain minimal weights. Again, if you are going to go to the trouble of installing your investment, then you want to do it in a way as your equipment will be safely protected.
You need to find the studs. All studs in a room should (should) be located 16 inches apart, so you have plenty of options for placement. To find a stud, you can use a magnetic stud finder (very inexpensive, from a hardware store.) While you’re at the hardware store, purchase four lag bolts at least 3 inches in length to replace the regular mounting screws.
Go ahead and mark on the wall where the holes will go, using the bracket as a guide. Next, drill a minimum of three inches into the wall using a drill bit that’s just a tad smaller in circumference than the lag bolt you will be using to mount the bracket. Now, all you do is attach the mounting hardware using the lag bolts, and you will be assured that your television and speakers will not be falling onto the floor, and that’s a good feeling, worth the extra precaution.