Its not, its very very real in terms of damping, because damping is exactly about what mechanical resistances the loudspeakers are involved in.
Which is why the 'only electrical' analysis gets the wrong answer.
well exactly, and as we all know, socialism in action doesn't work.
What I am really saying is that the electrical analysis alone does not provide the correct picture. The mechanical issues are relevant.
The cones are NOT mechanically coupled. The loudspeakers do not see the same mechanical load, especially when they are asymetrically situated in a cabinet.
Two electric motors in series do NOT work the same as two electric motors in parallel, This was an issue that came home to me years ago in analysing why two electric motors in series did not spin two model aircraft propellors at anything like the same speed. As the motor with a bit more load slows down, the voltage across it drops, and the voltage across the other motor rises, exacerbating the difference.
The current, and therefore the torque, is the same, but under different loads the torque being constant doesnt keep the motor speeds as near constant as having the same voltage across both motors - i.e. in parallel.
In the 'theoretical ' case of 'identical ' motors and propellors, it doesn't matter. In practice people found their twins trying to fly in circles..
worst of all, if one motor gets stopped the other one instantly burns out....