Not knowing the system off the top of my head here is some advice.
The Ohms should be the same as whatever the amp says it is rated at.
The power of the speaker should match or be better than what the amp is rated at.
As long as you follow this, you won't have a problem. Just remember never run everything at full volume, start off slow and see how it works as you turn it up.
Thanks. I've heard a fee conflicting answers just lately, usually I have always matched the power and Ohms of the speakers and Receiver, but its been a while. lol. The power matches, but the receiver uses 6 Ohms. I haven't bought anything yet, but plan on upgrading soon.
Ok, so what that means is this
Your 8 ohm speaker will not allow the amp to go as loud as possible, but will also be loud.
It's more dangerous to put a LOWER ohm speaker on a high ohm amp.
So for instance, if you connect your 8ohm speaker to the 6 ohm amp - if it was 100 watts, you may only be pushing 70 watts now.
These numbers are used for example and are not real.