First off this regards 2 Infinity 12" 1230ws in a common chamber 2 cuft sealed box in my room running of this olld kenwood home stereo. I disconnected one sub and played music at a moderate volume through the single, connected sub. Of course, this sub moving also made the other sub move... And then I noticed it. The 2 wires coming from the disconnected sub's svc4ohm coil, were almost touching, and every time the connected sub moved the other, there were little sparks jumping from the disconnected sub's wires... So I know in essence electricity makes a subwoofer move back and forth, but I know now that a sub moving back and forth, can also make electricity... Lame? Oh well, It was cool to me...
its the same priciple used in those "ever lite" flashlites. (the ones on Tv that you just shake and they produce lite)
the only real difference in those flashlite and a speaker are that the lite have a stationary coil and a movable magnet (just the opposite of a speaker...and the lites have a power storage device (prolly just a capacitor).
marshall those lights have a tiny capicator, my buddy got 2 of them from china b4 they were on tv. lol
Ever heard of "Faraday's Law" ?
Faraday is to be thanked for capictors. Capacitance is also measured in Farads, which is huge number, hence we mostly use micro farads.
Faraday's Law: Any change in the magnetic environment of a coil of wire will cause a voltage (emf) to be "induced" in the coil. No matter how the change is produced, the voltage will be generated. The change could be produced by changing the magnetic field strength, moving a magnet toward or away from the coil, moving the coil into or out of the magnetic field, rotating the coil relative to the magnet, etc.
this leads to issues like damping factor, and impedance fluctuations in drivers, which plays a part in both SQ and SPL systems with subs if you get into the grit of it which you'll find a lot of in the big competition vehicles. It's something that pretty much any serious competitor will understand if he has the slightest understanding of the mechanics of a magnetic transducer (speaker.)
i figured this our when i was little, maybe around 6 or 7. i use to take my toys apart and build stuff with the little electric motors inside. but i put the axels from the motors together and only put power to one. My dad told me he was gonna show me somthing and he took a voltmeter,(i dont know if thats what it was) and the motor with no power going to it was producing a little power. nothing big, but it produced somthing.
it heavly relates to the impedance flux in drivers! thus the constant change of impedance being presented to the amplifier.
amp speaker outputs AC voltage & AC current, then you get capacitance & inductance which will change your impedance depending on many things including freq.
if i remember correctly, the formula of impedence (Z) = resistance ( R) is Z= capacitance (C) + inductance (L)
Z = C + L
Note that impedance (Z) and Resistance ( R) use the same unit of "Ohms" Impedence is related to AC Resistance to DC
well you would add the DC resistance of the coil R plus the impedance of the coil as an inductor(Zl) plus the impedance of the coil as a capacitor(Zc).
Zl = jwL (j = imaginary number, w = omega which is the frequency, and L = the value of inductance)
Zc = 1/jwC (same as before except C = value of capacitance)