Hi. I skimmed the second article you linked. I did an MS thesis on chaotic dynamics in electronic circuits many years ago, so I get the general drift of the paper. Chaotic responses generally entail multiple stable or quasi-stable states. An example is an umbrella - it is normally concave downwards, but a gust of wind can snap in concave upwards. When driven by a large alternating gust, like in front of the monster subs you want to make, it may oscillate chaotically between the two states.
The paper didn't describe the physical mechanism behind the chaos but I suspect it's due to cone breakup. In fact, it's very similar to the umbrella I described - the cone can flex so much that the mechanical restoring force resisting bending starts to decrease and may even go to zero and reverse direction (in which case the cone could get stuck in the deformed condition). The large amplitude signal is forcing the cone to to flex in breakup modes with highly nonlinear restoring forces, and this generates the chaotic response. This has actually been used by guitarists seeking a very grungy sound, driving a speaker deep into breakup, or even cutting the speaker cone to assist breakup. Maybe the chaotic response is the source of the unique sound of speaker breakup.
In any event, the THD of the speaker will be very large before any chaotic response occurs, so the chaotic response will occur in some region between "sounds like cr*p" and "oh sh*t the speaker's on fire".
The paper didn't describe the physical mechanism behind the chaos but I suspect it's due to cone breakup. In fact, it's very similar to the umbrella I described - the cone can flex so much that the mechanical restoring force resisting bending starts to decrease and may even go to zero and reverse direction (in which case the cone could get stuck in the deformed condition). The large amplitude signal is forcing the cone to to flex in breakup modes with highly nonlinear restoring forces, and this generates the chaotic response. This has actually been used by guitarists seeking a very grungy sound, driving a speaker deep into breakup, or even cutting the speaker cone to assist breakup. Maybe the chaotic response is the source of the unique sound of speaker breakup.
In any event, the THD of the speaker will be very large before any chaotic response occurs, so the chaotic response will occur in some region between "sounds like cr*p" and "oh sh*t the speaker's on fire".