How many electrons?


There is a lot of current between your amp and your speakers. Imagine that you are doing some normal listening to your favorite loud music, and consider the number of electrons that move between the amp output poles and the speaker cables every second, in either direction.

Among the following estimates for the number of such electrons, which one is the most accurate?

a) None
b) Between eighty seven and a thousand
c) Thousands
d) Millions
e) Billions
f) Trillions or more

It's OK to just guess, but if you want to use numbers, the unit of current is an ampere, which is a coulomb per second, and an electron has a charge of about
1.602176487(40)×10−19 coulombs.
trebejo
(F)Trillions or more.

Actually, on musical peaks it would be well over a million trillion. Not sure what point you are trying to make, though.

Regards,
-- Al
I estimate a googol.
I'm with Al,not sure what point you are trying to make, though.Please elaborate.
One hundred million billion trillion zillion.....or maybe just seven.

Pepe
Trick question. Between none, and a few hundred, as the electrons dont really move much in AC current, it is the wave that moves.
This is a crude and non-scientific wording, so the words may be incorrect, but the IDEA is correct.
The drift velocity of electrons in audio cables is about 1 cm/hr. So the real answer is approximately zero.

Cheers
Geoff and Elizabeth, note that the question referred to "the number of electrons that move between the amp output poles and the speaker cables every second, in either direction."

As I interpret it, that clearly refers to the number of electrons moving past a single, specific, fixed location (in either direction) in a given amount of time. That location being either of the two connection points between amplifier and speaker cable (although any other point in the run could be chosen without affecting the answer). Based on that interpretation, my answer is correct.

If the question had been how many electrons travel from one amplifier terminal through the cabling and speaker to the other amplifier terminal, then yes the answer would be approximately zero. But that was not the question, as I read it.

Regards,
-- Al
Zero - that is obvious one
Well, at least if it is a trick question there is a point, I suppose.
12, if you've got the fat cable with the really big electrons.
None, the electrons stay very close by their atoms, but the signal causes another electron to move, and so on.

All metals are a "sea" of electrons on the surface - using voltage is like pushing water in a tub.
Only 2 electrons.

One to hold the bulb and the other to turn the chair.

Basic electrical theory.
Lady and Gentlemen,

Expanding on my previous post, the facts that electrons that are moving in response to an ac voltage "don't move much," and "stay very close by their atoms," and have a very slow drift velocity, all of which I agree with, do not change the fact that during each second trillions of electrons will flow back and forth across any given cross-section of the conductor.

Yes, each electron will move an EXTREMELY small distance during each half-cycle of the signal, but nevertheless those trillions of electrons will cross the plane of that cross-section during a given half-cycle, and will then cross it again in the opposite direction during the next half-cycle.

As I said earlier, if the OP was asking about the number of electrons that might make a complete round-trip from amp terminal to speaker and back to the other amp terminal, then I certainly agree that the number would be zero or close to it (my compliments to Geoff for including the word "approximately" in that regard, reflecting the fact that there is always some non-zero degree of randomness in electron movement). And I don't think we can say with certainty what the OP meant, without further clarification from him. But a literal interpretation of the wording of his question, IMO, suggests that the answer is trillions, not zero.

Regards,
-- Al
The OP was trying to relate the number of electrons at the amplifier output to the current, which is why he included the math for charge per electron and ampere. If one accepts his premise that the number of electrons available at the amp's output is proportional to the current, then for the one Ampere case the number of electrons would be around 10 to the power 19. More than a trillion trillion.

Cheers
As I said earlier, if the OP was asking about the number of electrons that might make a complete round-trip from amp terminal to speaker and back to the other amp terminal, then I certainly agree that the number would be zero or close to it

Almarg, would the close to it part be do to any resistance?
The number which would make the round trip might be some whole number, only because of the incredible number involved. So some, just because of random behavior, even though it is VERY unlikely, might just by chance manage the amazing feat.
As mentioned electrons actually on average drift 1 cm per hour. and that is sort of the thing here. They are drifting in an A/C current about the same as if not any current. For DC current: "For an electric current of 1 ampere, 1 coulomb of electric charge (which consists of about 6.242 × 10to18 power (or 6,242,000,000,000,000,000) elementary charges (electrons) drifts every SECOND through any plane through which the conductor passes."
So if there is a slight DC current Even a tiny DC (Direct current) current of 0.00001 ampere ,there are a LOT of electrons flying around from amp to speaker and back.

OK for you math wizards:
How small a DC offset in volts, would be needed to allow an average of one electron per second to start the round trip from amp output to speaker, through speaker wires etc and back if the total distance traveled is 100ft. and how long would it take the electron, on average? (this is reasonable considering all the coils, and wires in the speaker. Assume it is a one driver speaker to avoid complications. (it has to be a pretty small offset!!!...And just so you know, I could not possibly answer the question I ask.)
Billions and billions.

Carl Sagan (not bifwynne)
06-10-11: Hifihvn
Almarg, would the close to it part be do to any resistance?
Elizabeth's subsequent post provided a good answer as to the reason for the "close to it" part:
06-11-11: Elizabeth
The number which would make the round trip might be some whole number, only because of the incredible number involved. So some, just because of random behavior, even though it is VERY unlikely, might just by chance manage the amazing feat.
The number of electrons that are involved, btw, is far larger than the "well over a million trillion" that I mentioned in my first post near the start of this thread. That number referred just to the number of electrons oscillating back and forth across a single cross section of the conductors, over a very short distance. A similar number of different electrons would be oscillating back and forth across every other cross section spaced some small distance apart over the length of each conductor.
06-11-11: Elizabeth
How small a DC offset in volts, would be needed to allow an average of one electron per second to start the round trip from amp output to speaker, through speaker wires etc and back if the total distance traveled is 100ft. and how long would it take the electron, on average?
I don't think that a meaningful answer can be calculated, because drift velocity is proportional to current (see this Wikipedia writeup), and for such a small current drift velocity would become essentially zero.

It should be noted, btw, that the 1 cm/hr figure that has been stated a number of times above will vary widely depending on current. As shown in the example near the bottom of the Wikipedia page, for 3 amps flowing through a 1 mm diameter (about 18 gauge) copper conductor, drift velocity is about 1 meter/hour. 3 amps rms corresponds to 72 watts into an 8 ohm load. A drift velocity of 1 cm/hr would correspond to a current of 30 milliamps in that size wire, which is 7.2 milliwatts into an 8 ohm load.

All in all, I'm starting to think that Bill (Audiofeil) had the best answer :-)

Regards,
-- Al
I can't believe how difficult this has been.

Stereo speakers run on AC. AC is Alternating Current. Since we use Alternating Current there is no net transfer of electrons to the speaker. (Your speakers are NOT like a car battery that you would charge with DC)

Simply put, if your speakers were being charged and electrons were constantly building up inside them then eventually they would become highly charged like a battery.
06-11-11: Shadorne
Stereo speakers run on AC. AC is Alternating Current. Since we use Alternating Current there is no net transfer of electrons to the speaker. (Your speakers are NOT like a car battery that you would charge with DC)

Simply put, if your speakers were being charged and electrons were constantly building up inside them then eventually they would become highly charged like a battery.
Hi Shadorne,

Agreed. I don't think anyone has said anything inconsistent with this.

Best regards,
-- Al
But the OP was not referring to the "transfer of electrons to the apeaker." Pretty sure that's what they call a Strawman Argument. LOL
Hey Al, so . . . you agree with Bill (Audiofiel). What do you have against Carl Sagan (not bifwynne)???
consider the number of electrons that move between the amp output poles and the speaker cables every second

The answer is still Zero. Alternating current has no net movement of electrons. Same as there is no net movement of air in your room when you listen to music.
06-11-11: Bifwynne
Hey Al, so . . . you agree with Bill (Audiofiel). What do you have against Carl Sagan (not bifwynne)???
My apologies, Bruce. I should have given that response at least a nomination for second place. My wife has frequently quoted that same Carl Sagan expression, so I guess Bill's analysis struck me as more novel.

Best regards,
-- Al :-)
Al, Carl said he forgives you. But just one more thing, why hasn't anyone given any thought about the poor forgotten angels and the lonely pin-head?? Sorry, the problem is I care too much about the feelings of others. Time for the meds. Later. Bruce (this is bifwynne, not Carl Sagan and not the pin-head)
Shadorne, the statement you quoted from the OP in your last post omits the words "in either direction," which were at the end of the OP's sentence.

None of the rest of us who have responded have interpreted the question as referring to net movement of electrons, or to transfer of electrons to the speaker. And none of the responses, including mine which have referred to the movement of trillions of electrons, have implied that there is any NET movement or transfer.

Best regards,
-- Al
Yeah, but real world electronics have at least a small amount of DC at the same time as whatever else it is doing. So.........
And how many electrons can dance on the head of a pin is the pin head question of the day, and more than the number of Angels? or not?
And i do have to say this whole exercise is rather like deciding how many angels.. etc
Thanks for the answers. This thread turned into a good one.
Yeah Liz, and what about the bunny rabbits???
IF we are talking about "Energizer Bunny" bunny rabbits...
Or ordinary 'common' rabbits?
Or the Monty Python and the Holy Grail 'rabbit'?
Or the "Easter Bunny"?
OR... even Playboy Bunny???
It matters a LOT. Please clarify.
With all these electrons it makes sense, IMHO, and an old-school repair guy and confirmed:

Proper design of audio signal should be at line level, NOT passive crossover components in the speaker.

Geese, Wilson et/al charges umpteen million dollars for speakers while missing the whole point. Pity that high-end audio* is so out to lunch, especially for what some charge! Sorry for the rant.

* With a few exceptions like ATC active 100's
Controlling electrons is like herding cats....
That makes a great saying.. i should trademark it!
Liz, a bunny rabbit doesn't like one cat, least of all a herd of cats. Which raises another interesting question for the Forum. If cats travel in herds rather than packs or pods, how do electrons get around? I never heard of an electron herd, pack, pod or gaggle. Where's Al, Stan or Bill when you have deep techncial questions?? Ooopps, time for meds again!
Ahah! the answer is electrons travel in "CLOUDS"
Sneaky hey
You want to avoid DC on the output since it creates drift velocity and eventually drains high quality electrons, that you paid for, from your expensive speaker cable.

It is likely that it already happened to you. Send me your cables and I will recharge them with highest quality electrons for very small nominal fee.
Kijanki, can you repair the old bucket of steam and shelf-stretching machine that I used in college? I think they lost their high quality electrons too. Thanks.