Given a speaker is 30 watts, which is louder, the one with higher current through it or the one with higher voltage across it. Lets say both speaker has variable impedance (so we can vary both current and voltage). According to my research and analysis, the current is what drives the coil to produce vibration and thus rarrifying the air molecules around, so it turns out that a larger current would mean larger loudness. So is it safe to say that current is directly proportional to loudness?
In other words, which is louder, a speaker that is driven by a 3 Ampere current back and forth oscillating at high frequencies but with low voltage or a speaker that has very large full swing peak to peak voltage from up to bottom but low current?