What model(s) are the amp(s) in question? What models are the speakers in question?
Without knowing the specs of either we can't really give you a definitive answer.
However, what you may be doing by "daisy chaining" the speakers is putting a load on the amp outside of what it can handle. While it's common practice to do this (the daisy chaining, not overloading) it's very important to make sure that the resulting final load is within your amp's specs. If your amp is only rated to 4 ohms and you put a 2ohm load to it, it won't be happy and could cause damage to your rig. Also, using the existing wiring might be causing you issues as well if you haven't verified that there's nothing else on the circuit.
Some more details on your equipment will go a long way, so start there.