You're welcome, celo.
IMO there is a little more to it than the numbers you've mentioned. For instance, how loud do you typically listen? The efficiency of the speaker would also play a role as to an accurate answer to your question. The fact that the wattage output capability is doubled when the impedance is halved is usually a sign of a high quality and power (current) capable device. The idea though is simply to avoid clipping. In general, if you're not listening at loud levels you would be fine.
IMO there is a little more to it than the numbers you've mentioned. For instance, how loud do you typically listen? The efficiency of the speaker would also play a role as to an accurate answer to your question. The fact that the wattage output capability is doubled when the impedance is halved is usually a sign of a high quality and power (current) capable device. The idea though is simply to avoid clipping. In general, if you're not listening at loud levels you would be fine.