Anant Need I remind you that this is audio and not electricity

? coz only there the parallel circuits work the way you mention

!! here things are different ! Also what current are we talking bout here ? if the voltage itself is 250Mv then the current ??
In Audio usually when we talk of line level signal its usually in terms of volts and this is not the actual electrical volts

!! so you cannot apply the theory of electricity here

!
Its the Audio Voltage (I don't know how to put in laymen's term),its the signal level from peak to peak of a sine wave of a audio signal

!
if you or anyone has a doubt,just try to keep the volume same of both the subs (or multiple) and unplug one (or the rest but one) subs input

if the sound level of the other sub doesn't increase please come back to me

hyeah: !
If even after all this one wants to go ahead then be my guest :indifferent14:!!
Regards.