Subs Create Electricity?


Silver Member
Username: Six

Flint, MI U.S.A.

Post Number: 354
Registered: Oct-05
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...

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 10935
Registered: Dec-03
remember a speaker is basically a coil of wire moving over a magnet.

not a bright idea running one sub in a shared box though.
nor leaving those leads that close together to watch the sparks.


New member
Username: Kirktcashalini

Glastonbury, Connecticut USA

Post Number: 1
Registered: Feb-06

Gold Member
Username: Southernrebel

Monroe, Louisiana USA

Post Number: 2034
Registered: Mar-04
yep...just like glass says, inductance.

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).

Silver Member
Username: B101

Queen City, NC USA

Post Number: 908
Registered: Sep-05
its simple. inductance!

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.

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 10952
Registered: Dec-03
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.)

Silver Member
Username: Shawnomak

HB, SK Canada

Post Number: 190
Registered: May-05
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.

Silver Member
Username: B101

Queen City, NC USA

Post Number: 921
Registered: Sep-05
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

Silver Member
Username: Tdisanto

Post Number: 489
Registered: Sep-05
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)

So Zeq (Equivalent impedance) = R + Zl + Zc Ohms

Silver Member
Username: B101

Queen City, NC USA

Post Number: 970
Registered: Sep-05
^^^ exactly Mike! =D
So impedeance would rise while playing audio!
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