Out of interest, how many Watts are the speakers rated at and how many Ohms? Answer in Watts RMS, please; not Watts "Peak Music Power" (which is meaningless). My speakers are rated at 10W RMS so bell wire is more than adequate. I calculated that the total resistance of 3m (doubled of course) is 0.25 Ohms. Not very significant for an 8 Ohm speaker.
In the end, the answer - if you've already got some bell wire - is to try it. As I mentioned previously, it won't do any harm. (It hasn't done my speakers or amp any harm. It hasn't melted the wire or insulation).