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drgolf975d
02-24-2006, 04:06 PM
I have read that it does not matter much if one speaker wire is longer or shorter than another; but is it "OK" to wrap excess speaker wire in a loop to make one side shorter than the other to hook up speakers or should I shorten the one side. I wanted to wrap in a loop so if I changed the speaker locations later I would not have to get new wire or have to splice together. The wire I am using is the New Monster wire which I believe is 12 gauge and I do not know if looping excess wire affects sound quality. I am a novice and new to the forum and appreciate your help.

JohnMichael
02-25-2006, 08:02 AM
I loop speaker wire without any negative effect. I would not wrap the wire into a coil. I do keep my speaker wires the same length but that is from my early learning about audio in that you want the current to arrive at the two speakers at the same time. I do not know if this is true but I have always followed it.

hermanv
02-28-2006, 12:23 PM
A tight loop will make an inductor (not a good one because both wires are looped). Inductance in a speaker cable is not a good thing, but like most things it's OK in moderation. Make the loop big, say a foot across and no more than 3 turns (all guesses).

Length is far more important due to uneven resistance than anything about signal arrival times. If one speaker were an inch closer to your ears than the other, and you wanted equal signal arrival time, that would require a difference in speaker cable length of 14 miles!

So difference in length becomes dependent on gauge, small gauge wires would have more impact on one speakers sound than a large gauge.

jneutron
02-28-2006, 12:29 PM
A tight loop will make an inductor (not a good one because both wires are looped). Inductance in a speaker cable is not a good thing, but like most things it's OK in moderation. Make the loop big, say a foot across and no more than 3 turns (all guesses).
Looping the extra wire will not increase the inductance of the system. Since the two wires are carrying the same but opposite direction current, creating a solenoid with the wire pair will end up cancelling the field of both wires..net result will be no change in inductance.

I tested this with #24 zip, #12 zip, #16 zip, and #10 twisted pair. Under no circumstances, did winding the wires into a loop change the inductance of the wire pair.

I also looped these wires around a Stanley Bostitch stapler, a coffee mug, the magnet assembly of a selenium d205ti tweeter driver, and the magnet structure of an eminence Delta 12. Under all conditions, there was no measureable change in the inductance. All tests were done using both an HP4162A and an HP 4263B.

(around the magnetic materials did indeed suprise even me..)

Cheers, John

GMichael
02-28-2006, 12:53 PM
Looping the extra wire will not increase the inductance of the system. Since the two wires are carrying the same but opposite direction current, creating a solenoid with the wire pair will end up cancelling the field of both wires..net result will be no change in inductance.

I tested this with #24 zip, #12 zip, #16 zip, and #10 twisted pair. Under no circumstances, did winding the wires into a loop change the inductance of the wire pair.

I also looped these wires around a Stanley Bostitch stapler, a coffee mug, the magnet assembly of a selenium d205ti tweeter driver, and the magnet structure of an eminence Delta 12. Under all conditions, there was no measureable change in the inductance. All tests were done using both an HP4162A and an HP 4263B.

(around the magnetic materials did indeed suprise even me..)

Cheers, John

Either you were very board, or you're one of those scientists I used to know back in Research.

jneutron
02-28-2006, 12:54 PM
Either you were very board, or you're one of those scientists I used to know back in Research.Both..:eek:

Actually, I was testing the fit of the Terman inductance equation against various wire geometries. Since I had it setup, and the question of proximity of speaker wire to magnetic entities and ceramic lifters had been bandied about I think over at AA, I decided to have fun. (I neglected to mention the CD jewel case and the Canon Powershot G-2, I figured nobody would wrap their wires around those..c'mon.....)

All the inductive measurements were within 4% of calculations for a 6 foot wireset in all four guages, at frequencies between 100 hz and 100 Khz, regardless of whether the wire was coiled on itself, or wrapped around anything at all. I attribute that error to the measurement of the actual wire spacing....I only used a dial vernier..had I really wanted to get silly, I could have used the laser thingy.

Cheers, John

JohnMichael
02-28-2006, 01:08 PM
Oh the memories.....

I can recall these conversations back in the day. Crazy Scientist guys carrying on about their experiments in supper conductors & such while I just stared at them, eyes glazing over, thinking about the new secretary that started on the 4th floor. Oh, those were the days.

Just as long as you were not thinking about work.

GMichael
02-28-2006, 01:10 PM
Both..:eek:

Actually, I was testing the fit of the Terman inductance equation against various wire geometries. Since I had it setup, and the question of proximity of speaker wire to magnetic entities and ceramic lifters had been bandied about I think over at AA, I decided to have fun. (I neglected to mention the CD jewel case and the Canon Powershot G-2, I figured nobody would wrap their wires around those..c'mon.....)

All the inductive measurements were within 4% of calculations for a 6 foot wireset in all four guages, at frequencies between 100 hz and 100 Khz, regardless of whether the wire was coiled on itself, or wrapped around anything at all.

Cheers, John

Oh the memories.....

I can recall these conversations back in the day. Crazy Scientist guys carrying on about their experiments in supper conductors & such while I just stared at them, eyes glazing over, thinking about the new secretary that started on the 4th floor. Oh, those were the days.

hermanv
02-28-2006, 01:33 PM
Looping the extra wire will not increase the inductance of the system. Since the two wires are carrying the same but opposite direction current, creating a solenoid with the wire pair will end up cancelling the field of both wires..net result will be no change in inductance.

I tested this with #24 zip, #12 zip, #16 zip, and #10 twisted pair. Under no circumstances, did winding the wires into a loop change the inductance of the wire pair.

I also looped these wires around a Stanley Bostitch stapler, a coffee mug, the magnet assembly of a selenium d205ti tweeter driver, and the magnet structure of an eminence Delta 12. Under all conditions, there was no measureable change in the inductance. All tests were done using both an HP4162A and an HP 4263B.

(around the magnetic materials did indeed suprise even me..)

Cheers, John
I agree, but I've always had some trouble expanding the thought to include how a coax impedance transformer balun could ever work. http://en.wikipedia.org/wiki/Image:Balun.jpg

jneutron
02-28-2006, 01:39 PM
Just as long as you were not thinking about work.
What do you mean??? That IS work.;)

I use Faraday's law of induction to calculate induced voltages, Amperes law for magnetic field calculations, Biot-Savart for magnetic field analysis, the Lorentz force law to determine the forces on the conductors, and Lenz's law for rapidly changing magnetic fields reaction to nearby metals.

The Terman equation is a simple extension of that stuff, and is useful for calculating the extent of reaction of a wire pair to high fields..we use #30 twisted pairs for differential taps in the magnets. No matter how tight you twist them, when the cable goes through gradient fields in the 150 to 300 tesla per meter range, the external inductance of the twisted pair can still pickup current slews and trip the detectors. So, very relevant to what I do.


Oh the memories.....

I can recall these conversations back in the day. Crazy Scientist guys carrying on about their experiments in supper conductors & such while I just stared at them, eyes glazing over, thinking about the new secretary that started on the 4th floor. Oh, those were the days..Women?? Women?? Oh man, you were lucky..

The scientists are not that bad. As long as you don't disturb them in their natural habitat, don't feed them, and don't...and I repeat, don't stick your hands or arms through the bars. They are there for your safety..:D

Cheers, John

GMichael
02-28-2006, 01:45 PM
Just as long as you were not thinking about work.

Yeah, well, I was just a poor Purchasing guy. These scientist guys would get so excited about their experiments that they would forget that I had no idea what they were saying. My question was usually something like, "how many of these did you want?" And then they'd going into all the details of the latest atom they were splitting that week. I did get to see a lot of cool stuff though. One project built a room where everything was a hologram inside. You could play handball with no ball and just a disembodied hand. It was like the holodeck. I got to meet the Russian chess master just before our computers took him down. Oh, the memories.

GMichael
02-28-2006, 01:48 PM
What do you mean??? That IS work.;)

The scientists are not that bad. As long as you don't disturb them in their natural habitat, don't feed them, and don't...and I repeat, don't stick your hands or arms through the bars. They are there for your safety..:D

Cheers, John

Scientists are way cool man. I got along great with all of them. Most of them loved what they were doing the way people here love their HT or music. Sometimes even more so. Many of them had matresses in their offices or labs so if they had a thought in the middle of the night they could get up and work on it.

jneutron
02-28-2006, 01:48 PM
I agree, but I've always had some trouble expanding the thought to include how a coax impedance transformer balun could ever work. http://en.wikipedia.org/wiki/Image:Balun.jpgNot being familiar with that thingy (that I can recall), I took the link back to the writeup.

Weird, they describe removing currents which travel on the outside of the braid...funny description, true of course, but definitely counter-intuitive.


The RF signal that is being carried by the coax has the current of the braid and the current of the center conductor. For the signal of interest, all the magnetic field of the signal is between the two conductors, purely within the dielectric. Outside of the shield, all magnetic field from the signal of interest is zero.

If there is any current travelling along the braid that is NOT also travelling back via the center conductor, it's magnetic field will not be cancelled, and the toroid will see it. In fact, the same would apply to any non signal currents in the center conductor that do not have an equal and opposite current in the shield.

So the device seems quite straightforward. A comparable device would be the toroid sensor in a GFI unit. That however, has two discrete wires, hot and neutral, which cancel out their equal but opposite currents in the GFI. It gets confusing when the wires are made coaxial to each other, and the description of operation is chock full of weird things.

Cheers, John

jneutron
02-28-2006, 02:06 PM
Scientists are way cool man. I got along great with all of them. Most of them loved what they were doing the way people here love their HT or music. Sometimes even more so. Many of them had matresses in their offices or labs so if they had a thought in the middle of the night they could get up and work on it.
They are the same way here.

We even have two retirees who still come to work every day in my division.. The lab provides them an office free of charge, and they do magnet work.

One guy here is 90 years old, he still travels around the world doin his thing..nicest guy, too.

Cheers, John

hermanv
02-28-2006, 02:06 PM
Not being familiar with that thingy (that I can recall), I took the link back to the writeup.

Weird, they describe removing currents which travel on the outside of the braid...funny description, true of course, but definitely counter-intuitive.


The RF signal that is being carried by the coax has the current of the braid and the current of the center conductor. For the signal of interest, all the magnetic field of the signal is between the two conductors, purely within the dielectric. Outside of the shield, all magnetic field from the signal of interest is zero.

If there is any current travelling along the braid that is NOT also travelling back via the center conductor, it's magnetic field will not be cancelled, and the toroid will see it. In fact, the same would apply to any non signal currents in the center conductor that do not have an equal and opposite current in the shield.

So the device seems quite straightforward. A comparable device would be the toroid sensor in a GFI unit. That however, has two discrete wires, hot and neutral, which cancel out their equal but opposite currents in the GFI. It gets confusing when the wires are made coaxial to each other, and the description of operation is chock full of weird things.

Cheers, John
Yeah, weird is right. lets see the field from the inside conductor is perfectly cancelled by the field of the outer conductor, so the inside field doesn't appear outside. Ok so far. Now somehow there is some outside field sort of left over from cancelling the inside field for the thingy to work? I understand the reduction of common mode current but they use these things to make RF impedance transformers, that's where I go Huh?

I just have some trouble reconcoilling this with the measurements you made about two conductors on a core, if it works for coax, couldn't it partially work for other wire arangements? Not that I know, but weird is as good a description as I've seen.

GMichael
02-28-2006, 02:29 PM
They are the same way here.

We even have two retirees who still come to work every day in my division.. The lab provides them an office free of charge, and they do magnet work.

One guy here is 90 years old, he still travels around the world doin his thing..nicest guy, too.

Cheers, John

That's how I would be if I were designing speakers for a living. But noooooooo I had to go into Purchasing. What was I thinking?

90 and still kickin' huh? That's great. Work is what he does for fun. I feel like I know him.

jneutron
02-28-2006, 02:30 PM
Yeah, weird is right. lets see the field from the inside conductor is perfectly cancelled by the field of the outer conductor, so the inside field doesn't appear outside. Ok so far. Now somehow there is some outside field sort of left over from cancelling the inside field for the thingy to work? I understand the reduction of common mode current but they use these things to make RF impedance transformers, that's where I go Huh?

I just have some trouble reconcoilling this with the measurements you made about two conductors on a core, if it works for coax, couldn't it partially work for other wire arangements? Not that I know, but weird is as good a description as I've seen.
Well, by weird, I meant the verbage. The device operation seems quite straight forward.

By design, all the current which is common to the braid and center will cancel out. The toroid sees only the difference. That difference is what is going through the shield only, for their example. Like a ground current.

My test result is easy. It is two cancelling transformers.any field enhancement caused by one conductor coil is exactly cancelled out by the opposite wire coil.

If you were to extend my test to the coax balum example you linked to, it wound be the equivalent of sending an additional current through one wire only. This is exactly how a GFI works too. The inductance meter does not work like that, it sends the current only in one wire and back the other.

Cheers, John