Correct speaker wire

[DonH56]

Corrected my post...

 

[Xulonn]

Wire goes to speaker and then comes back. So the total length/resistance is twice as much or 12 feet.

I actually do understand that electrons jump from atom to atom in a wire and don't flow independently like cars down a freeway. And I also understand that current is flow and voltage is potential and their combined "power" is used to overcome resistance and related factors that "resist" or "impede" the flow of electrons.

However, I don't really "grok" the differences between resistance, impedance, inductance, and other factors that affect electron flow - and understand that heading down that rabbit hole can raise more questions than provide quick and easy answers - and tthat many aspects of electronics require a solid background in advanced mathematics. I got as far as Ohm's Law and quit.

But it's good that many engineers, scientists and technicians understand these phenomena well enough to control and utilize them. I've got just enough "conceptual" knowledge about electronics to vaguely understand some of the detailed technical discussions here - and even enough to quite often be able to detect ignorance-based claims that turn out to be snake oil.

(Of course, I'm probably wrong about something in this post, and I'm sure that at least one of our "technical experts" will point it out. But taking a chance and voicing your "understanding" or a physical process or environment - and being corrected - is how many of us learn.)

 

[DonH56]

Don't worry about electron flow. Impedance (Z) includes resistance (R) and reactance (X): Z = R + jX. The j is for the imaginary part of the impedance and is equal to square root of (-1). Look up complex numbers (mathematicians use "i" instead if "j"; EE's use "j" so it does not conflict with AC current which is also "i"). The reactance can be capacitive, inductive, or a mix of both.

I'll stick with basic ideal components so we can say:

• A pure resistor just has resistance R in ohms.
• Capacitor (C) impedance varies inversely with frequency (f) so XC = 1/(2*pi*f*C), magnitude in ohms.
• Inductor (L) impedance varies directly with frequency so XL = 2*pi*f*L, magnitude in ohms.

So over frequency, a pure resistor stays at R ohms, but a capacitor's impedance (reactance) goes down as frequency goes up, and an inductor's impedance goes up as frequency goes up. That means a capacitor passes more current, or has less voltage drop across it, as frequency increases. An inductor will have higher voltage drop across it or less current through it as frequency goes up.

• If you put a capacitor in series with the signal, it will block low frequencies and pass high frequencies.
• If you put an inductor in series with the signal, it will pass low frequencies and block high frequencies.

There are probably lots better descriptions on the net, with videos and pictures, but hopefully that gives you the basic idea.

HTH - Don

 

[Wes]

Impedance is for all circuits and includes resistance as a special case when the signal is DC. Music is AC.

I'm sure there is a wiki that would help with these concepts, and likely a Dummies Guide too.

A simple analogy of electricity is to a garden hose...

voltage ~ water pressure

current ~ water flow or flow rate

resistance ~ clamping down on the hose

 

[DonH56]

 

[somebodyelse]

Impedance is for all circuits and includes resistance as a special case when the signal is DC. Music is AC.

I'm sure there is a wiki that would help with these concepts, and likely a Dummies Guide too.

A simple analogy of electricity is to a garden hose...

voltage ~ water pressure

current ~ water flow or flow rate

resistance ~ clamping down on the hose

You stopped before the interesting bits! https://en.wikipedia.org/wiki/Hydraulic_analogy

 

[Xulonn]

A simple analogy of electricity is to a garden hose...

voltage ~ water pressure

current ~ water flow or flow rate

resistance ~ clamping down on the hose

Now you're talking my language!!!

And yes, I have actually eaten a Vegemite sandwich - in California.

 

[TankTop]

Wire goes to speaker and then comes back. So the total length/resistance is twice as much or 12 feet.

completes the circuit, makes perfect sense, thank you.

 

[Alice of Old Vincennes]

All these gauges remind me of my vape days..

Spoiler: For those that don't understand the meme

Vaping relies on usually hand wound coils with a moistened wick filled with "e-liquid" when vaporized turns into the vaper desired. The device sends a current through a the coil, and depending on the resistance, and such things like gauge, usually speaking, the more mass a coil has, the more vapor you can produce. Now a cloud comp, is a vaping competition where people do smoke tricks or try to produce the biggest amount of vapor. And you will usually see in such competitions, guys working on their coils. Hence the meme of trying to make the biggest coil in hopes of not shorting the device potentially or other factors while producing the biggest "cloud" of vapor.

I remember the ten gallon water pipes fed with a garden hose in the 70's. The only "coil" you needed to worry about concerned the lungs.

 

[RayDunzl]

However, I don't really "grok" the differences between resistance, impedance, inductance, and other factors that affect electron flow

My feeble understanding, might help:

Resistance - provides the same "obstruction" to current flow whether the voltage applied is DC or AC. More volts = more current immediately.

Reactance - the difference between change in current and change in voltage when the circuit has inductance or capacitance, sort of a sliding resistance

Impedance - the net of resistance and reactance

Applying a DC voltage:

Capacitive reactance - an uncharged capacitor looks like a "short" - current flows quickly at first, and slower as the capacitor charges up, and the voltage across it rises. Eventually there is no more current flow. The capacitor builds a charge across its plates to the limit of the voltage. a fully charged capactor looks like an "open".

Inductive Reactance - Voltage across the inductor is high at the beginning, it looks like an "open", it impedes current flow, then current flow rises, eventually to look like a "short", the opposite effect of a capacitor. The inductor limits flow as it builds a magnetic field around the inductor.

AC across a capacitor - current "leads" voltage - the phase of the two are not locked together like across a resistor.

AC across an Inductor - Voltage "leads" current.

Resistance in series with the inductor or capacitor forms a time constant - the exponential rate at which the cap can charge, or the inductor builds its field.

If you want to do the calculations be sure to grab your imaginary calculator because, if I remember correctly, there are imaginary numbers involved.

 

[Wombat]

Don't worry about electron flow. Impedance (Z) includes resistance (R) and reactance (X): Z = R + jX. The j is for the imaginary part of the impedance and is equal to square root of (-1). Look up complex numbers (mathematicians use "i" instead if "j"; EE's use "j" so it does not conflict with AC current which is also "i"). The reactance can be capacitive, inductive, or a mix of both.

I'll stick with basic ideal components so we can say:

• A pure resistor just has resistance R in ohms.
• Capacitor impedance varies inversely with frequency (f) so XC = 1/(jfC), magnitude in ohms.
• Inductor impedance varies directly with frequency so XL = jfL, magnitude in ohms.

So over frequency, a pure resistor stays at R ohms, but a capacitor's impedance (reactance) goes down as frequency goes up, and an inductor's impedance goes up as frequency goes up. That means a capacitor passes more current, or has less voltage drop across it, as frequency increases. An inductor will have higher voltage drop across it or less current through it as frequency goes up.

• If you put a capacitor in series with the signal, it will block low frequencies and pass high frequencies.
• If you put an inductor in series with the signal, it will pass low frequencies and block high frequencies.

There are probably lots better descriptions on the net, with videos and pictures, but hopefully that gives you the basic idea.

HTH - Don

I know you know this Don:

XC = 1/2.pi.f.C

XL = 2.pi.f.L

 

[DonH56]

I know you know this Don:

XC = 1/2.pi.f.C

XL = 2.pi.f.L

Oh good grief. Two stupid mistakes in as many days. I think my insane work hours and lack of sleep are catching up to me. I am used to writing frequency in radians per second (w) and w = 2*pi*f so when I made the last-second change to Hz (because most people are used to that) simply left off the 2*pi factor. Duh.

As for leaving the "j" in, well, I got nothing...

Thanks, corrected... - Don

 

[Wombat]

Oh good grief. Two stupid mistakes in as many days. I think my insane work hours and lack of sleep are catching up to me. I am used to writing frequency in radians per second (w) and w = 2*pi*f so when I made the last-second change to Hz (because most people are used to that) simply left off the 2*pi factor. Duh.

As for leaving the "j" in, well, I got nothing...

Thanks, corrected... - Don

 

[Wombat]

Yep. My XC and XL should have had magnitude symbols(lXCl and lXLl , confusing) in lieu of -j and +j respectively.

Without mathematical/engineering characters on a keyboard, equations can get cumbersome.

 

[Wombat]

A basic look at RLC circuits:

https://courses.lumenlearning.com/physics/chapter/23-11-reactance-inductive-and-capacitive/

https://courses.lumenlearning.com/physics/chapter/23-12-rlc-series-ac-circuits/

 

[HammerSandwich]

You forgot to multiply by 2 Don since it is a roundtrip.

Don uses directional cables to keep the resistance low.

 

[TankTop]

My dad is an electrical engineer, high voltage transmission lines, substations, nuclear power plants and used to design and build his own tube amps but he can’t explain this stuff to save his life, you guys aren’t much better

what’s funny to me about hifi is it’s something that should be basic science but there’s a human factor that carries emotion and feeling and the science and engineering must become more poetic in nature.

anyway I’m just waiting on my coffee.

 

[Wombat]

My dad is an electrical engineer, high voltage transmission lines, substations, nuclear power plants and used to design and build his own tube amps but he can’t explain this stuff to save his life, you guys aren’t much better

what’s funny to me about hifi is it’s something that should be basic science but there’s a human factor that carries emotion and feeling and the science and engineering must become more poetic in nature.

anyway I’m just waiting on my coffee.

Your dad studied EE for years with all its maths and physics to understand this stuff and you expect it to be delivered to you, at your level of understanding, in an easy grab-bite.

I get the feeling he knows he would be wasting his time.

 

[TankTop]

Your dad studied EE for years with all its maths and physics to understand this stuff and you expect it to be delivered to you, at your level of understanding, in an easy grab-bite.

I get the feeling he knows he would be wasting his time.

that was a bit harsh and somewhat off base... I‘M fully aware I’m not going to understand it nor am I going to spend the time to master it but it is fascinating and enjoyable to me to read about it.

As a side note he didn’t go to school for it, started out making wire in the warehouse but he does write all over other engineers drawings who did go to school for it. He’s one of those people who just gets it while everyone else spends years trying to figure it out.

In my line of work most people can do the work but don’t grasp it, that’s true on this forum as well! What category do you fall into?

 

[Wombat]

that was a bit harsh and somewhat off base... I‘M fully aware I’m not going to understand it nor am I going to spend the time to master it but it is fascinating and enjoyable to me to read about it.

As a side note he didn’t go to school for it, started out making wire in the warehouse but he does write all over other engineers drawings who did go to school for it. He’s one of those people who just gets it while everyone else spends years trying to figure it out.

In my line of work most people can do the work but don’t grasp it, that’s true on this forum as well! What category do you fall into?

Professional EE who started out as a technician. High voltage power systems. Generation, transmission and distribution - operation, control, design, maintenance and safety. Also policy, procedure and work instruction formulation and implementation.

Senior lead auditor ISO 9000 Quality Assurance Management systems. This is one job where you have to 'get it', and fast.

My reply was pointed in response to your unfair put-down of members in your post. You have since given some insight as to why your dad may find it difficult to explain things.

Post #7 will do the job.

Enjoy your coffee.