Could you be a little more vague?
It's only two cables, two connections on each end for a total of 8 connections. There's not a heluva lot to screw up here.
Does it do it on all sources? If only a few, it's the source.
If on all, it's either the speakers or the receiver.
If you never heard these speakers or receiver before and they are used, option 2 is a good possibility