Just wondering, if anyone has an opinion on the topic -- the other day a co-worker was telling me that some installers are now running Cat6 cable in the walls for line level audio distribution. I know the twists in CatX cable are of a very high quality, but is there a case for it actually being superior to the standard audio cable being used out there? Is there any more of an advantage to using Cat6 over the older Cat5/5e to carry line audio?

Just wondering, if anyone has an opinion on the topic -- the other day a co-worker was telling me that some installers are now running Cat6 cable in the walls for line level audio distribution. I know the twists in CatX cable are of a very high quality, but is there a case for it actually being superior to the standard audio cable being used out there? Is there any more of an advantage to using Cat6 over the older Cat5/5e to carry line audio?

I don't know of any advantages...unless extreme distances are involved. The bandwidth of audio is pretty low compared to video over the same CAT cabling.

I currently use an A-bus system with CAT5e....never have had a problem since I installed in 2001.

I know the twists in CatX cable are of a very high quality, but is there a case for it actually being superior to the standard audio cable being used out there?

No, twisted wires are not magical.
If the audio is balanced then cat 5/6 will be fine.
Unbalanced audio should use a shielded cable.

At my old job we had Cat5e run all over the place for both audio and video. It works fine and is way cheaper to implement on the distances we were using. Everything sounded fine so I am guessing that it is at least the same quality as regular cable.

Just wondering, if anyone has an opinion on the topic -- the other day a co-worker was telling me that some installers are now running Cat6 cable in the walls for line level audio distribution. I know the twists in CatX cable are of a very high quality, but is there a case for it actually being superior to the standard audio cable being used out there? Is there any more of an advantage to using Cat6 over the older Cat5/5e to carry line audio?

There are at least two theoretical reasons cat 5 should make a great choice for line level audio interconnects. Many users seem to swear by the stuff. It's hard to argue with the logic considering how inexpensively this stuff can be obtained.

Since it is designed to be used with extremely high bandwidth digital signals the impedance is tightly controlled during design and manufacture The norm is that extremely hiigh quality dielectric insulator material is used even for the cheap stuff. The result is ultra low low capacitance cables allowing them to have exceptional bandwidth....read virtually ruler flat frequency response throughout the audio band.

The other thing is the common mode noise rejection inherent in twisted pair configuration is very very good. The act of twisting the wires extremely reduces the current loop areas (read reduce antenna efficiency) and does wonders for detuning these cables to the ability to resonate (form standing waves) in the presence local ambient EMI noise field energy.

The downsides: low gauge, ie not suitable for a high current signal such as high powered speaker cable.

Also, I wouldn't use anything shielded (cat6) unless absolutely necessary as the shielding can be coupled with by the audio signals thus coloring sound.

The other thing is the common mode noise rejection inherent in twisted pair configuration is very very good.

Twisted conductors don't reject noise....this is a common myth, often repeated in these fora.

Also, I wouldn't use anything shielded (cat6) unless absolutely necessary as the shielding can be coupled with by the audio signals thus coloring sound.

wow! I mean, it doesn't even make sense.

Twisted conductors don't reject noise....this is a common myth, often repeated in these fora.



wow! I mean, it doesn't even make sense.

You're clearly not an EE are you? Suffice to say you may want to do a little research before making such statements.

You're clearly not an EE are you? Suffice to say you may want to do a little research before making such statements.
Duvetyne is correct. Twisted pairs don't magically reject noise. Generally wires are twisted together to induce noise equally so that noise may be rejected ONLY in balanced and/or differential setups. This allows the signal to be much more immune to noise, sometimes not even requiring shielding depending on the application. Non-balanced lines need shielding or else interference will be introduced into a line level signal.

Also, I wouldn't use anything shielded (cat6) unless absolutely necessary as the shielding can be coupled with by the audio signals thus coloring sound.
And i too feel this makes no sense.

Twisted pairs don't magically reject noise.

Your right it isn't magic it's physics. I take it by your comments you haven't studied it much either.

Generally wires are twisted together to induce noise equally so that noise may be rejected ONLY in balanced and/or differential setups.

Not sure what you are saying here but sounds somewhere out in left field.

As I said earlier the twisted pair wire configuration can be used when reduced antenna effect to ambient noise fields is desirable. Antenna effect is related to the geometry and composition of the antenna and ambient noise fields character. These two things alone determine the amount of energy recieved by a given antenna in a given noise field. This noise energy will mix with any signals being conducted on these lines regardless of their nature. One type of antenna is known as a current loop antenna. Loop (for short) antennae gain is dependent on a number of factors one of which includes the loop area as seen by whatever fields the loop is located within. The act of twisting the wires reduces loop area significantly lowering antenna gain by detuning the antenna to most of the frequencies present in typical ambient noise fields. As you might imagine the current loops found in audio systems may also act as antennae.

If you are truly interested in learning more about this try a google search for "current loop antenna effect".

Non-balanced lines need shielding or else interference will be introduced into a line level signal.

I take it you meant to say lines carrying balanced signals. ;) Differential signals traveling on those same lines would see the same noise energy as single ended signal assuming all else equal, The one difference is that differential signals swing both ways instead of one yielding twice the signal to noise ratio for a given signal level and noise energy level which have been mixed on a signal carrying conductor.

Shielding can be used to reduce noise field intensity on either single ended or differential signal carrying conductors. Signal type matters not. Of course, in practice shielding is imperfect and can only reduce noise field intensity not eliminate it.

And i too feel this makes no sense.

Signal wires encapsulated in shielding will experience both capacitive and inductive coupling with the shield conductor....again it's physics. These parasitics will draw energy off from the signal which gets attenuated in eddy currents etc resulting in distortion.

If you truly would like to learn more about this you may want to investigate what is known as inductive and/or capacitive coupling. They are two mechanisms of the observed effect that some of the energy from a signal on a conductor will be transferred to nearby conductors. Any time you remove energy from a signal it is altered aka distorted. The operation of transformers and coupling capacitors is based on these effects being real. Energy really does go into one coil of a transformer and out from the other even though high levels of electrical isolation between the coils may exist. Energy truly does go into one series capacitor lead and out the other and yet there is usually a very highly non conductive dielectric seperating the plates.

Your right it isn't magic it's physics. I take it by your comments you haven't studied it much either.



Not sure what you are saying here but sounds somewhere out in left field.



Um, no, thats the reason wires are twisted together, it is so that any noise induced on the conductors are as close to equal as possible, and in a balanced connection that noise cancels out. Without the twist, the induced noise is not equal and won't fully cancel.

His explanation is not in left field at all, it's basic theory.


As I said earlier the twisted pair wire configuration can be used when reduced antenna effect to ambient noise fields is desirable. Antenna effect is related to the geometry and composition of the antenna and ambient noise fields character. These two things alone determine the amount of energy recieved by a given antenna in a given noise field. This noise energy will mix with any signals being conducted on these lines regardless of their nature. One type of antenna is known as a current loop antenna. Loop (for short) antennae gain is dependent on a number of factors one of which includes the loop area as seen by whatever fields the loop is located within. The act of twisting the wires reduces loop area significantly lowering antenna gain by detuning the antenna to most of the frequencies present in typical ambient noise fields. As you might imagine the current loops found in audio systems may also act as antennae.

That has nothing to do with it.


If you are truly interested in learning more about this try a google search for "current loop antenna effect".

Try googling twisted pair instead.


I take it you meant to say lines carrying balanced signals. ;) Differential signals traveling on those same lines would see the same noise energy as single ended signal assuming all else equal, The one difference is that differential signals swing both ways instead of one yielding twice the signal to noise ratio for a given signal level and noise energy level which have been mixed on a signal carrying conductor.

No, again you're missing the entire point. A balanaced line (which isn't necessarily differential and doesn't need to be), ensures that any noise induced on both conductors travels back to ground and cancels out because the impedance to ground in a balanced line is the same. That is why balanced cabling implementations like data UTP doesn't need to be shielded compared to a non-balanced line like coax. The noise that is induced in the balanced line cancels out, whereas on an unbalanced line the noise adds to the signal and hence noise problems, that's why coax is heavily shielded.

Your differential signal twice the SNR explanation is bologna, that has nothing to do with it at all.


Shielding can be used to reduce noise field intensity on either single ended or differential signal carrying conductors. Signal type matters not. Of course, in practice shielding is imperfect and can only reduce noise field intensity not eliminate it.

Right, but you really NEED to have shielding to protect an unbalanced line, whereas a balanced line protects itself, and is aided by the twist geometry. Shielding on a balanced line is a bonus.


Signal wires encapsulated in shielding will experience both capacitive and inductive coupling with the shield conductor....again it's physics. These parasitics will draw energy off from the signal which gets attenuated in eddy currents etc resulting in distortion.

If you truly would like to learn more about this you may want to investigate what is known as inductive and/or capacitive coupling. They are two mechanisms of the observed effect that some of the energy from a signal on a conductor will be transferred to nearby conductors. Any time you remove energy from a signal it is altered aka distorted. The operation of transformers and coupling capacitors is based on these effects being real. Energy really does go into one coil of a transformer and out from the other even though high levels of electrical isolation between the coils may exist. Energy truly does go into one series capacitor lead and out the other and yet there is usually a very highly non conductive dielectric seperating the plates.

Of course capacitance is real. What does that have to do with noise rejection? Nothing.

Um, no, thats the reason wires are twisted together, it is so that any noise induced on the conductors are as close to equal as possible, and in a balanced connection that noise cancels out. Without the twist, the induced noise is not equal and won't fully cancel.

On a read back through my original post I now see that I mistakenly did say "common" mode noise rejection and it clearly should have been differential mode noise rejection that I said. For that reason I agree you do have a half a point here. However both duvetyne and jarrod1937 were were both arguing that twisted pairs offers no immunity to any noise at all which clearly isn't true. I made a simple and honest mistake in my original wording which is obviously wrong. Is this what you are taking issue with?

The half point removed is due to your own sloppy wording since wire twisting does nothing in itself to reduce common mode noise only differential noise.

That has nothing to do with it.

It is unclear what you disagree with. That differential noise can be recieved on a conductor via antenna effect or that twisting reduces it. Please explain what your disagreement is and attempt to explain why you disagree. As it stands now I disagree with your disagreement. :)

Try googling twisted pair instead.

That's probably a good one too but the search I recomended gets the job done when correctly taken in the context of the originl topic and the point I was disagreeing with jarrod1937 on where he was agreeing with duvetynes statement "Twisted conductors don't reject noise". It really helps to keep things in the context they were clearly intended to be taken in.

A balanaced line (which isn't necessarily differential and doesn't need to be),

This turned out to be the interesting search for me. I looked at balanced vs differential and now understand. My wording in response to jarrod1937 was bad, wrong, whatever. However to the original topic and my original post this is irrelevant. I do, however, concede this point.

No, again you're missing the entire point. A balanaced line (which isn't necessarily differential and doesn't need to be), ensures that any noise induced on both conductors travels back to ground and cancels out because the impedance to ground in a balanced line is the same.

Actually this time it is you who is missing the point. The original question was regarding twisted pairs. Twisted pairs does increas differential noise immunity which I now see balanced circuits absolutely would be susceptible to just as unbalanced circuits will be. The point made about differential not equal balanced, while correct, is irrelevant to the point being made in my first post to OP and the point I thought I was making in my reply to jarrod1937 which I now understand where that replys weakness lies. Thanks for the one thing, but in this case you may want to rethink the other.

Your differential signal twice the SNR explanation is bologna, that has nothing to do with it at all.

While it may have nothing to do with the topic as I've now learned thanks to your motivating post it absolutely is not balogna. The explanation given about why differential signaling is used and useful is correct.

but you really NEED to have shielding to protect an unbalanced line, whereas a balanced line protects itself, and is aided by the twist geometry.

On the one hand I partly agree in that balanced lines with or without twisted conductors are would appear to be more immune to differential noise than unbalanced by circuit design. There is still something wrong about what you said.

The more correct statement is: Both balanced and unbalanced circuitry carrying either single ended or differential signaling are susceptible to differential noise which is reduced by using twisted conductors. Also all purmutations of balanced and unbalanced circuitry combined with single ended and differential signal types could potentially see reduced noise from shielding. Balanced circuitry can be more immune to differential noise than unbalanced and differential signaling is more immune to differential noise than single ended signals.

None of this says anything about common mode noise which may or may not be dealt with by design as well.

Of course capacitance is real. What does that have to do with noise rejection? Nothing.

Who said it did? Perhaps you ought to put the statement in the context it was given. Shielding causes its own signal integrity issues just as it can eliminate other types of signal integrity issues and part of it is due to the capacitance between the shielding and signal conductor pairs. It is the signal integrity issues it causes I was pointing out.

In summary: yep you've helped me see some real booboos I made. Thanks for that and I apologise to all who may be reading for any confusion it caused. At the same time I am even surer now than ever that both duvetyne and jarrod1937were completely incorrect and you made a doozy or two yourself.

Twisted conductors don't reject noise....this is a common myth, often repeated in these fora.


???????????????????

The benefits of twisted pair and balanced inputs, which go hand-in-hand, are well known, both theoretically and practically.

If anything about interconnects is myth, its the semi-myth that shielding is effective at audio frequencies, and the usual impedance levels for line-level signals.

This is getting to be a moot topic, as digital interconnections continue to take over. There's also been a major shift of digital interconnections to twisted pair and balanced operation.

Duvetyne is correct. Twisted pairs don't magically reject noise.


Right no magic, just science.


Generally wires are twisted together to induce noise equally so that noise may be rejected ONLY in balanced and/or differential setups.


Agreed, but thre are three other advantages to twisting wires.

(1) Minimizes the area within the loop created by the wires.

(2) The grounded conductor creates a partial sheild for the ungrounded conductor in unbalanced circuits.

(3) At high frequencies, twisting wires is a cheap and easy way to create a uniform transmission line. This is not relevant to line-level signals at audio frequencies.



This allows the signal to be much more immune to noise, sometimes not even requiring shielding depending on the application.


Agreed. However the minimization of area within the loop is also significant.

Take a six foot piece of twisted pair, and untwist it and reconfigure the wires so that they form the largest possible loop. There will be a measureable difference, and likely even an audible difference in hum pick up.

Note that in a balanced circuit twisting balances capacitive pickup. Any current that is induced into the loop formed by the two conductors is not common mode and the balanced input won't cancel it out.


Non-balanced lines need shielding or else interference will be introduced into a line level signal.


I've experimented with those unshielded unbalanced audiophile cables, and found that the ones that are based on twisted pair weren't as horrible as I expected. They actually worked pretty well.

The usual rule of thumb is that below 10 KHz and at line levels, shielding doesn't have a lot of effectiveness.

I would say that wikipedia is en rather excellent starter source of information in how TP-cables transfers signals and the different things involved.

http://en.wikipedia.org/wiki/Twisted_pair

I run digital audio/component video over cat5e with zero issues into two rooms. There are many baluns that work well, I have extras too!

I have also run HDMI over Cat6 using Genfen baluns.

There are several popular home automation systems that have been running over cat5e/cat6 for many years successfully so its all a moot discussion because it DOES work well! Not sure of all the balanced discussion back and forth since those with full house systems run digital most times. The shielding debate is way overrated too, some people need to worry less about theory and just buy and use ;)

You can post this question in the PROPER forum, AVS has a Home video/audio distribution forum ;)

Audio Authority AVAtrix is a cat5e/cat6 system, that many have. I would have bought it before I ran cables in my new house but I went RG6 to many rooms and I went DIY with ebay Extron purchases that cost 1/10th their original cost.


Here is the AVAtrix official thread....
http://www.avsforum.com/avs-vb/showthread.php?t=806109

The benefits of twisted pair and balanced inputs, which go hand-in-hand, are well known, both theoretically and practically.

Not by most of you , unfortunately.

Differential receivers...look it up sometime.

If you have to run cables, run the proper cables and be done with it.

On a read back through my original post I now see that I mistakenly did say "common" mode noise rejection and it clearly should have been differential mode noise rejection that I said. For that reason I agree you do have a half a point here. However both duvetyne and jarrod1937 were were both arguing that twisted pairs offers no immunity to any noise at all which clearly isn't true. I made a simple and honest mistake in my original wording which is obviously wrong. Is this what you are taking issue with?

The half point removed is due to your own sloppy wording since wire twisting does nothing in itself to reduce common mode noise only differential noise.



It is unclear what you disagree with. That differential noise can be recieved on a conductor via antenna effect or that twisting reduces it. Please explain what your disagreement is and attempt to explain why you disagree. As it stands now I disagree with your disagreement. :)



That's probably a good one too but the search I recomended gets the job done when correctly taken in the context of the originl topic and the point I was disagreeing with jarrod1937 on where he was agreeing with duvetynes statement "Twisted conductors don't reject noise". It really helps to keep things in the context they were clearly intended to be taken in.



This turned out to be the interesting search for me. I looked at balanced vs differential and now understand. My wording in response to jarrod1937 was bad, wrong, whatever. However to the original topic and my original post this is irrelevant. I do, however, concede this point.



Actually this time it is you who is missing the point. The original question was regarding twisted pairs. Twisted pairs does increas differential noise immunity which I now see balanced circuits absolutely would be susceptible to just as unbalanced circuits will be. The point made about differential not equal balanced, while correct, is irrelevant to the point being made in my first post to OP and the point I thought I was making in my reply to jarrod1937 which I now understand where that replys weakness lies. Thanks for the one thing, but in this case you may want to rethink the other.



While it may have nothing to do with the topic as I've now learned thanks to your motivating post it absolutely is not balogna. The explanation given about why differential signaling is used and useful is correct.



On the one hand I partly agree in that balanced lines with or without twisted conductors are would appear to be more immune to differential noise than unbalanced by circuit design. There is still something wrong about what you said.

The more correct statement is: Both balanced and unbalanced circuitry carrying either single ended or differential signaling are susceptible to differential noise which is reduced by using twisted conductors. Also all purmutations of balanced and unbalanced circuitry combined with single ended and differential signal types could potentially see reduced noise from shielding. Balanced circuitry can be more immune to differential noise than unbalanced and differential signaling is more immune to differential noise than single ended signals.

None of this says anything about common mode noise which may or may not be dealt with by design as well.



Who said it did? Perhaps you ought to put the statement in the context it was given. Shielding causes its own signal integrity issues just as it can eliminate other types of signal integrity issues and part of it is due to the capacitance between the shielding and signal conductor pairs. It is the signal integrity issues it causes I was pointing out.

In summary: yep you've helped me see some real booboos I made. Thanks for that and I apologise to all who may be reading for any confusion it caused. At the same time I am even surer now than ever that both duvetyne and jarrod1937were completely incorrect and you made a doozy or two yourself.

How about some tests. http://www.adireaudio.com/Files/CarCables.pdf

How about some tests. http://www.adireaudio.com/Files/CarCables.pdf

First of all the OP's question was related to "standard audio cable " not coax. I never said said one bad thing about coax.

Second coax isn't without it's own set of care and feeding requirements. There are many downsides to coax but to keep things in context I'll just mention one. Since it isn't what I would consider to be truly shielded in the traditional sense, ie uses it's outer conductor as one of the signal current carrying conductors, external fields will couple to the outer conductor. Point is it isn't impervious to radiation either. It can be beat in the area of radiated noise immunity by STP cabling. Note that professionals have universally gravitated to the use STP cables for the most sensitive low level signals such as mic feeds and phono signals and not coax.

Finally what's with this idea of posting listening tests? This is the theory forum. ;-)

I would say that wikipedia is en rather excellent starter source of information in how TP-cables transfers signals and the different things involved.

http://en.wikipedia.org/wiki/Twisted_pair

Yes, thanks for the link.

The first line seems very applicable to the arguments here:

Twisted pair cabling is a form of wiring in which two conductors (the forward and return conductors of a single circuit) are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources;

See this duvetyne? sound vaguely familiar?

Not by most of you , unfortunately.

Differential receivers...look it up sometime.

Jeez man that is about the lamest attempt at an argument on this subject I've ever seen. How would differential recievers have anything to do with the physics of the cabling hooked up to them other than the net loop impedance it presents which could be precisely identical to a single ended recievers net loop impedance? :rolleyes: You clearly aren't getting the whole antenna effect arguments being made.

First of all the OP's question was related to "standard audio cable " not coax. I never said said one bad thing about coax.

Second coax isn't without it's own set of care and feeding requirements. There are many downsides to coax but to keep things in context I'll just mention one. Since it isn't what I would consider to be truly shielded in the traditional sense, ie uses it's outer conductor as one of the signal current carrying conductors, external fields will couple to the outer conductor. Point is it isn't impervious to radiation either. It can be beat in the area of radiated noise immunity by STP cabling. Note that professionals have universally gravitated to the use STP cables for the most sensitive low level signals such as mic feeds and phono signals and not coax.

Finally what's with this idea of posting listening tests? This is the theory forum. ;-)

Last time I checked "standard audio cable " is coax (CHEAP, MAYBE NOT WELL SHEILDED) but still coax. STP cables have been used on "pro" mics and MM/MC phonos forever because they are feed from an audio transformer or a pickup coil that produces a balanced signal. So a STP cable is the correct thing to use in those applications.

http://www.shure.com/ProAudio/Products/us_pro_ea_audiotransformer

PS. I don't know what you mean by "listening tests". My link was pure electronics and test instruments.

Last time I checked "standard audio cable " is coax

lol. The fact that you would say this indicates you are reeaallly reaching hard, or you haven't been alive very long. The "standard" has been two or three wire not configured as coax, for many many years.

So a STP cable is the correct thing to use in those applications.

I agree it is the correct thing to use in those apps, but it's not as though coax couldn't be used in these apps. As has been correctly been pointed out several times now balnced lines and twisted pairs are unique entities. There is no requirement to use one with the other even though it CAN be done that way. I guess I'm not seeing what point you are trying to make if it is something other than just arguing for its own sake.

PS. I don't know what you mean by "listening tests". My link was pure electronics and test instruments.

My mistake. For some reason , perhaps in haste, I thought you said "some listening tests" which I thought odd based on your link. Now it makes more sense.

See this duvetyne? sound vaguely familiar?
Correct me if i'm wrong but the same article gives the impression that the twisting is only used to keep noise common-mode in order to be able to reject it in balanced lines (like the phones systems mentioned). This does not apply to the transmission of a line level signal like the op mentioned.
Though the above statement is only in response to the article for which you're citing, arnyk already gave some good reasons for using twisted pairs. To me it just feels like you're taking that quote out of context though.

p.s. thanks arnyk for giving a nice and clear explanation, always useful.

lol. The fact that you would say this indicates you are reeaallly reaching hard, or you haven't been alive very long. The "standard" has been two or three wire not configured as coax, for many many years.


Sure. Lets see what Blue jeans says for unbalanced audio. http://www.bluejeanscable.com/store/audio/index.htm
http://www.bluejeanscable.com/articles/humrejection.htm

When did you get your first formal training in electronics. I had a FCC first radio telephone ticket in 1974. :D

Correct me if i'm wrong but the same article gives the impression that the twisting is only used to keep noise common-mode in order to be able to reject it in balanced lines (like the phones systems mentioned).

My understanding is:

There are benefits in differential noise rejection which can had by simply by using twisted pair ( the on topic subject of discussion here) as compared to using two random wires shaped into some big or small area loop antenna. There are also potential benefits to be had in rejecting differential noise by using balanced line circuitry as compared to using unbalanced circuitry. There is a difference between those concepts and the distinction is important in the context of the discussion here.

I don't believe there is a requirement or that article or any other states there is a requirement that balanced circuitry requires twisted pair cabling but the benefits of using the two together will be complementary, ie there is a double differential noise reduction whammy when used together.

Common mode noise is different, and twisted pair cabling does nothing to prevent it. Dealing with common mode noise gracefully is a commonly followed good practice since it can blow up gear but implementation may be different from techniques employed to deal with differential noise immunity. Both balanced and unbalanced circuitry may or may not contain circuit enhancements designed to offer better common mode noise circuit immunity, it depends on the whims of the circuit designer.

This does not apply to the transmission of a line level signal like the op mentioned.

It does. Please see premise of wiki twisted pair site I quoted. It reduces loop antenna area as compared to other two wire runs and thus reduces recieved differential noise.

Though the above statement is only in response to the article for which you're citing, arnyk already gave some good reasons for using twisted pairs.

Actually arnyk's main point which seems to be "(1) Minimizes the area within the loop created by the wires." is merely echoing the sentiment I tried making in my original post: it reduces a type of noise audio circuitry is susceptible to which is caused by antenna effect. Admittedly as Chris Wiggles helped me see my wording had a flaw in that I said it was reducing common mode noise but if you read my response to Chris you'd see that I agree this was an error on my part. The real antenna effect addressed by twisted pairs is differential noise recieved via current loop antenna.

To me it just feels like you're taking that quote out of context though.

It certainly wasn't my intent and I hope this post helps clear that up.

Sure. Lets see what Blue jeans says for unbalanced audio.

double lol! An audio cable manufacturer as a source intended to squelch audiophile "myths"? Please forgive me for questioning your choice of sources. You wouldn't have anything slightly more credible than the testimony of a guy trying to sell something would you?

When did you get your first formal training in electronics.

Well my first training was somewhere around '73 when I discovered it isn't a good idea to try use your fingers and remove a broken bulb from a lamp that isn't turned off or unplugged. ;)

I don't want to brag but my involvement is in a professional capacity for over ten years and continuous since my formal training began somewhere in the early 90's.

I had a FCC first radio telephone ticket in 1974.

A ham license? What class? The level that struck me as being slightly challenging when I looked at test samples was expert. But I suspect a couple days reviewing smith charts and other related topics is all I'd need to get that, well besides all the memoriztion of useful things like morse code. The memorizing part could take longer. Forget about it, why even bother. I don't mean to minimize your accomplishment or the cool factor of having ham license but you'll note that having a ham license wont open many doors when it comes to procuring employment as an electronics professional. There is a fairly good reason for that. IMO ham tests are less likely to weed out operators in favor of designers than a degree from an accredited uni. I'm sure there are exceptions.

I feel bad for the OP.

A ham license?

Ha Ha!!! http://en.wikipedia.org/wiki/General_radiotelephone_operator_license

A FCC first radio telephone ticket is a:

Radio Telephone Operator License - First Class

It is what is/was required to be a principle broadcast engineer at a radio or TV station.
Lesser licenses are/were 2nd and 3rd class.
I have not kept up on the current rules.
Received my 1st phone ticket in 1965.

Ha Ha!!! http://en.wikipedia.org/wiki/General_radiotelephone_operator_license

Ahh. That does sound a bit more intense than I first imagined. I understand the boys in blue can get pretty picky when one starts splattering all over other bands with any kind of real power. I've always figured it would be fun to hang out at a big healthy station for a while and try and pick up some tricks from a battle hardened old dog radio engineer re high fidelity radio transmission/reception.

Have you checked out that newer movie "The Boat that Rocked"? About a late sixties pirate radio station over by UK. Not much in the way of cool radio gear other than big antennae and huge tower, but there is some cool old military grade looking turntables in the DJ booths though. I thought it was fun to watch.

I feel bad for the OP.

lmao! :D


Im sure he has moved on (why wouldnt he after I have posted ;)) but they will keep on with irrelevant back in forth. It sounds like none of them even have full house audio/video :confused:

lmao! :D


Im sure he has moved on (why wouldnt he after I have posted ;)) but they will keep on with irrelevant back in forth. It sounds like none of them even have full house audio/video :confused:

I have full house AV but mine is all networked. I don't have to run long audio or video cables. Using Mythtv and linux my entire HD video/music/picture collection can be accessed anywhere I have a wired or wireless connection. I use cat5/5e/6 cables for the the transfer of IP packets not analog signals. :)
I have over 10 computers in the house capable of 1080P output with 4 media, security and network servers with over 20TB or storage. http://mysite.verizon.net/res02dad/sitebuildercontent/sitebuilderpictures/PA270042.jpg
Hey, irrelevant banter is at the heart any good meeting place. ;)

Ahh. That does sound a bit more intense than I first imagined. I understand the boys in blue can get pretty picky when one starts splattering all over other bands with any kind of real power. I've always figured it would be fun to hang out at a big healthy station for a while and try and pick up some tricks from a battle hardened old dog radio engineer re high fidelity radio transmission/reception.

Have you checked out that newer movie "The Boat that Rocked"? About a late sixties pirate radio station over by UK. Not much in the way of cool radio gear other than big antennae and huge tower, but there is some cool old military grade looking turntables in the DJ booths though. I thought it was fun to watch.

I didn't do much public type broadcasting. The sites I managed were mainly military/government in far away places. ;)

I have full house AV but mine is all networked. I don't have to run long audio or video cables. Using Mythtv and linux my entire HD video/music/picture collection can be accessed anywhere I have a wired or wireless connection. I use cat5/5e/6 cables for the the transfer of IP packets not analog signals. :)
I have over 10 computers in the house capable of 1080P output with 4 media, security and network servers with over 20TB or storage. http://mysite.verizon.net/res02dad/sitebuildercontent/sitebuilderpictures/PA270042.jpg
Hey, irrelevant banter is at the heart any good meeting place. ;)


Yes, that good old method of having PCs everywhere. Thought about it but decided to centralize and maximize my sources. Same movie in three rooms at once great for when family wants to lay down somewhere else but watch the same movie, XBox360, PS3 anywhere in the house is pretty cool, well the wireless connection fails at over 30 feet :( so the one back bedroom doesnt work but all other rooms are good for gaming. I can have one BD player and play any new BD in any room or all rooms. I maximized my $$$ over you and I can send multi streams because of my centralization. I also do not need any boxes in rooms ;)

you have me beat with 20TB, I have 3 TB of DVDs (thats 500 movies!) and music....20TB is scary ;) I do not have security history needs though.

as for the irrelevant banter....I did not get to almost 14000 posts by staying on point all the time! I guess Im the poster child for it :D

I feel we might as well benefit from a conversation if its gathered steam, even if its irrelevant to the op's problem. Thus to continue...


There are benefits in differential noise rejection which can had by simply by using twisted pair (the on topic subject of discussion here)
I think the point of discrepancy is that i am unsure what you're talking about when speaking of differential noise rejection. When i speak of it i am speaking of differential signaling that can reject common-mode noise, because if noise is induced equally into the differential system, the difference is not really changed. However you say it is the topic of discussion, but the op's signal is an unbalanced, single ended, non-differential signal. So maybe i am just not understanding your terminology, that or perhaps i missed a post or two that turned the discussion into one of a different signal than the op's.

security and network servers with over 20TB or storage.
Holy crap! That's a lot! What kind of raid system are you using? Or are they all independent NAS's?

All that to watch "Plan 9 From Outer Space" and to play Pong?

I think the point of discrepancy is that i am unsure what you're talking about when speaking of differential noise rejection.

Pulled from some random internet site since I can't seem to say anything lately without making mistakes but it happens to line up exactly with my definition too:

"Differential Mode Noise: Noise that is measured between two lines with respect to a common reference point excluding common-mode noise. The resulting measurement is the difference of the noise components of the two lines."

However you say it is the topic of discussion, but the op's signal is an unbalanced, single ended, non-differential signal.

I actually missed where the OP mentioned what he's running but it doesn't matter. Both balanced and unbalanced circuitry will respond to differential noise and it will mix with single ended or differential signaling. It can be a problem for all electronic circuitry and signaling types. It just happens that balanced circuits and differential signaling each in and of themselves offer more, but still imperfect, immunity to it than single ended signaling and unbalanced circuitry each offer in and of themselves.

...AND twisted pair cabling is one tool which can be used as an also imperfect differential noise prevention measure.

Here is a more concise definition that i was able to find:

Noise is classified into two types, differential mode noise and common mode noise.

Differential mode noise is conducted on the two power supply lines in opposite directions to each other, as shown in Fig.1(a).

Common mode noise is conducted on all lines in the same direction, as shown in Fig.1(b).

Which makes more sense why its called differential...

Edit: never mind, i was able to answer all of my questions with further searching. And now i think we're on the same page.

All that to watch "Plan 9 From Outer Space" and to play Pong?

Did you hack my systems? I got both on my servers.

I didn't do much public type broadcasting. The sites I managed were mainly military/government in far away places. ;)

Would you have to kill us if you told us? :D

Holy crap! That's a lot! What kind of raid system are you using? Or are they all independent NAS's?

Sorry OT.

I have two levels of storage. I have a work-shed (wire Gbit network) detached from the house for backup of important docs and files. This has scsi raid 1 for the OS and scsi u360 raid 5 for backups. I use unix "rsync" to backup the critical data from other machines to this server. I then have a old HP 400/800 LTO4 tape drive to make archives. (left overs from a computer center upgrade at work)

The main media servers are JBOD because mythtv's future release (that I run) will have storage groups that auto combine single drives to one big logical media block. Any shows that I want to archive gets flagged and moved to a special folder that gets mirrored across systems and drives. About 1/3 of my storage is just for backups.

If I yank the plug out, then what?

BTW you have to be sure to get Glen or Glenda to play after Plan 9. The very best of Ed Wood.

I have 2- JVC BR-3500 VHS decks, 2 Umatic Sony 9600 recorders, 3 dual well Panasonic cassette recorders and a couple thousand cassettes too. Oh yea I have a DVD recorder.

I don't generate enough data to fill a 6o gb drive let alone a few TBs.

Ah the simple life.

Would you have to kill us if you told us? :D

Not anymore, most of the places I worked were closed when everything when to sats for primary data transmission. State side example. http://en.wikipedia.org/wiki/Sugar_Grove,_West_Virginia

I've been in semiconductor wafer fabs for the last 20 years (Oregon mainly) working on high energy (3 MeV+) ion implanters.
http://www.agsemiconductor.com/files/M7THE707.pdf
http://cas.web.cern.ch/cas/ZEUTHEN/Zeuthen-talks/150903/Pichhoff_linac%20lecture.pdf

Correct me if i'm wrong but the same article gives the impression that the twisting is only used to keep noise common-mode in order to be able to reject it in balanced lines (like the phones systems mentioned). This does not apply to the transmission of a line level signal like the op mentioned.
Though the above statement is only in response to the article for which you're citing, arnyk already gave some good reasons for using twisted pairs. To me it just feels like you're taking that quote out of context though.

p.s. thanks arnyk for giving a nice and clear explanation, always useful.

Of course it applies. That's the whole point, you utilize UTP along with BALUN adapters (BALanced to UNbalanced, and vice versa) in order to get the benefits of balanced transmission, hence the use of twisted pair for that purpose. Obviously if you don't use baluns and just physically adapt the cabling to UTP or the like, then that gets you nowhere and is a terrible idea.

My understanding is:

There are benefits in differential noise rejection which can had by simply by using twisted pair ( the on topic subject of discussion here) as compared to using two random wires shaped into some big or small area loop antenna. There are also potential benefits to be had in rejecting differential noise by using balanced line circuitry as compared to using unbalanced circuitry. There is a difference between those concepts and the distinction is important in the context of the discussion here.

Stop separating these two things. A twisted pair is utterly useless unless it is being used over a balanced line. You can take two conductors and twist them together all you want for analog audio and it won't make a damn bit of difference unless the line is a balanced line, in that case it makes a huge difference.


I don't believe there is a requirement or that article or any other states there is a requirement that balanced circuitry requires twisted pair cabling but the benefits of using the two together will be complementary, ie there is a double differential noise reduction whammy when used together.

No. Please stop confusing everything together and apart. Again, differential is a distinct subset of balanced transmission. A balanced line may or may not be differential.

There is not any kind of "double whammy." There is only one noise rejection principle at work here, and it is common mode noise rejection across the balanced line, and the pair twist aids in improving this noise rejection attribute. If you twist a pair on an unbalanced line, you've accomplished nothing and rejected no noise at all.


Common mode noise is different, and twisted pair cabling does nothing to prevent it. Dealing with common mode noise gracefully is a commonly followed good practice since it can blow up gear but implementation may be different from techniques employed to deal with differential noise immunity. Both balanced and unbalanced circuitry may or may not contain circuit enhancements designed to offer better common mode noise circuit immunity, it depends on the whims of the circuit designer.

This is totally nonsensical.



It does. Please see premise of wiki twisted pair site I quoted. It reduces loop antenna area as compared to other two wire runs and thus reduces recieved differential noise.



Actually arnyk's main point which seems to be "(1) Minimizes the area within the loop created by the wires." is merely echoing the sentiment I tried making in my original post: it reduces a type of noise audio circuitry is susceptible to which is caused by antenna effect. Admittedly as Chris Wiggles helped me see my wording had a flaw in that I said it was reducing common mode noise but if you read my response to Chris you'd see that I agree this was an error on my part. The real antenna effect addressed by twisted pairs is differential noise recieved via current loop antenna.



It certainly wasn't my intent and I hope this post helps clear that up.

Of course it applies. That's the whole point, you utilize UTP along with BALUN adapters (BALanced to UNbalanced, and vice versa) in order to get the benefits of balanced transmission, hence the use of twisted pair for that purpose. Obviously if you don't use baluns and just physically adapt the cabling to UTP or the like, then that gets you nowhere and is a terrible idea.
Ok, i didn't know there were adapters for changing from unbalanced to balanced. In that case then it is quite relevant even to the op.

One word keeps popping up and when applied to the real world of long run balanced audio lines and noise injection/rejection,


TRANSFORMERS They work, they solve all kinds of problems that differential inputs to opamps cannot solve or frequently create.

I would estimate I have installed. or modified and maintained about 10 thousand systems of all sizes with cable runs into the thousands of feet on individual lines. For permanent installs like field runs and rack wiring I use a simple foil shielded STP Belden 8451. For all portable lines I use only Canare L4E6S.

We have also used STP premise wiring quite successfully to distribute audio between rooms and floors in office buildings.

The majority of hum problems I have had to deal with were caused by someone trying to connect balanced to unbalanced w/o using a transformer.

Many of the systems I have installed are used for major public activities that include broadcast and satt-link operations. This includes major security installations and government facilities.

I have found that when someone tries to build a better mousetrap in the audio industry that all too frequently the old tried and true transformer is the cure-all.

I have built a nice assortment of problem solvers that are kept in my tech kit that have been designed over the years to combat all types of analog interconnect issues. Most everyone uses a transformer plus some other goodies.

Remember folks, transformers are our friends. With the proper transformer and STP, you can do many wonderful things grasshopper.

TRANSFORMERS

... more than meets the eye.:p

Stop separating these ...blah blah...
This is totally nonsensical.

No. Links have been provided which explain it satisfactorily. None of the links support your assertions.

Ok, i didn't know there were adapters for changing from unbalanced to balanced. In that case then it is quite relevant even to the op.A BALUN is a transformer working at RF. It will do squat at audio frequencies, where you need, as Gizmologist states above, a specifically designed audio transformer.

Might be worth reading this for some of the less technical people here.
http://www.jensen-transformers.com/an/an004.pdf

A BALUN is a transformer working at RF.

No, a BaLun is a Balanced to Unbalanced (or vice versa) transformer. It can operate at audio frequencies as well as video and RF.

One word keeps popping up and when applied to the real world of long run balanced audio lines and noise injection/rejection,


TRANSFORMERS They work, they solve all kinds of problems that differential inputs to opamps cannot solve or frequently create.

I would estimate I have installed. or modified and maintained about 10 thousand systems of all sizes with cable runs into the thousands of feet on individual lines. For permanent installs like field runs and rack wiring I use a simple foil shielded STP Belden 8451. For all portable lines I use only Canare L4E6S.

We have also used STP premise wiring quite successfully to distribute audio between rooms and floors in office buildings.

The majority of hum problems I have had to deal with were caused by someone trying to connect balanced to unbalanced w/o using a transformer.

Many of the systems I have installed are used for major public activities that include broadcast and satt-link operations. This includes major security installations and government facilities.

I have found that when someone tries to build a better mousetrap in the audio industry that all too frequently the old tried and true transformer is the cure-all.

I have built a nice assortment of problem solvers that are kept in my tech kit that have been designed over the years to combat all types of analog interconnect issues. Most everyone uses a transformer plus some other goodies.

Remember folks, transformers are our friends. With the proper transformer and STP, you can do many wonderful things grasshopper.

Right, and the other very happy benefit that using Baluns affords you is that it breaks ground, so no ground loops if that is an issue.

A BALUN is a transformer working at RF. It will do squat at audio frequencies, where you need, as Gizmologist states above, a specifically designed audio transformer.

Might be worth reading this for some of the less technical people here.
http://www.jensen-transformers.com/an/an004.pdf

Ridiculous. There are scores of audio transformers out there, and that's really all Baluns are at the end of the day. There are baluns designed for different bandwidths and different tasks (such as video baluns for instance, digital audio, etc). But there certainly are analog audio baluns of various types from various manufacturers. I've used scores of them.

No. Links have been provided which explain it satisfactorily. None of the links support your assertions.

I don't even know what it is you are disagreeing with.

I really only made two simple claims, that the benefits of twisting a pair of conductors is solely to ensure that induced noise is as close to equal on both conductors so it will cancel as common mode noise, and this only occurs on a balanced line. If the line is not balanced, twisting the pairs does nothing for you.

And the other is pointing out as before that the line may or may not be differential (the signals are symmetrically inverse), regardless of whether it is balanced. This is a common source of confusion in that people often assume that balanced=differential signaling when that isn't always the case.

I'm not sure what issue you find with either of these two fairly basic statements of fact?

Ridiculous. There are scores of audio transformers out there, and that's really all Baluns are at the end of the day. There are baluns designed for different bandwidths and different tasks (such as video baluns for instance, digital audio, etc). But there certainly are analog audio baluns of various types from various manufacturers. I've used scores of them.

I with you, I have boxes full off used Baluns for one test or another. Digital audio, analog audio. Baluns for Cat5e, Baluns for HDMI.....I have used them all.

I with you, I have boxes full off used Baluns for one test or another. Digital audio, analog audio. Baluns for Cat5e, Baluns for HDMI.....I have used them all.

Though the terminologically nitpicky among us would refer to HDMI "baluns" as media adapters, they're not just transformers, but the term gets used frequently because it's a box and it goes from one cabling/connector type to another. ;)

Though the terminologically nitpicky among us would refer to HDMI "baluns" as media adapters, they're not just transformers, but the term gets used frequently because it's a box and it goes from one cabling/connector type to another. ;)

Okay, Gefen called them HDMI "baluns" but I wont argue the nitpicky terms....Im just a buyer of products.

Right. Sometime I just call them baluns myself. But it's good to know in the back of your mind that isn't really what they are...

I don't even know what it is you are disagreeing with.

I really only made two simple claims, that the benefits of twisting a pair of conductors is solely to ensure that induced noise is as close to equal on both conductors so it will cancel as common mode noise, and this only occurs on a balanced line. If the line is not balanced, twisting the pairs does nothing for you.

And the other is pointing out as before that the line may or may not be differential (the signals are symmetrically inverse), regardless of whether it is balanced. This is a common source of confusion in that people often assume that balanced=differential signaling when that isn't always the case.

I'm not sure what issue you find with either of these two fairly basic statements of fact?

Your first statement shows you don't understand the nature of noise induced by external fields onto a conductor, how impedances, and wire geometry play a part in how this noise energy manifests itself.

I will try to help: balanced vs unbalanced - deals with impedances. differential vs single ended - deals with the nature of the signals themselves, specifically their voltages. Wire geometry - deals with EM theory of the systems interaction with itself and surrounding environment. To say that any of these things are necessarily related would be technically incorrect per the definitions of each of them regardless of existing industry trends.

Your first statement shows you don't understand the nature of noise induced by external fields onto a conductor,

No, it show that he knows why the wires are twisted together in a balanced interconnect. You, clearly, still don't get this.


I will try to help: balanced vs unbalanced - deals with impedances. differential vs single ended - deals with the nature of the signals themselves,

You're simply incorrect in your understanding of the oldest method of transmitting audio signals.

No, a BaLun is a Balanced to Unbalanced (or vice versa) transformer. It can operate at audio frequencies as well as video and RF.I said a balun was a transformer, and it is.

A balun typically used to connect a dipole antenna to a 75R transmission line, will not work as an audio transformer in any useful way. This use, plus later HF variations used for data and networking are pretty much the same.

For it to work at AF, it will typically need a larger core CSA and considerably more primary inductance.

My point was that if you go into ratshack and ask for a balun, you'll get something like this.
http://www.summitsource.com/images/products/COTRAN.jpg

Different brand, opened to show the insides.
http://www.user.dccnet.com/jonleblanc/images/philips-balun3.jpg

Which will not be useful at all at AF, where you need a proper AF transformer whether or not you want to call it a balun or not. I've been doing PA for a long time and no one has ever referred to a matching transformer this way to me, whereas it's usage in RF is commonplace.

Just wondering, if anyone has an opinion on the topic -- the other day a co-worker was telling me that some installers are now running Cat6 cable in the walls for line level audio distribution.

I said a balun was a transformer, and it is.

A balun typically used to connect a dipole antenna to a 75R transmission line, will not work as an audio transformer in any useful way. This use, plus later HF variations used for data and networking are pretty much the same.

For it to work at AF, it will typically need a larger core CSA and considerably more primary inductance.

My point was that if you go into ratshack and ask for a balun, you'll get something like this.
http://www.summitsource.com/images/products/COTRAN.jpg

Different brand, opened to show the insides.
http://www.user.dccnet.com/jonleblanc/images/philips-balun3.jpg

Which will not be useful at all at AF, where you need a proper AF transformer whether or not you want to call it a balun or not. I've been doing PA for a long time and no one has ever referred to a matching transformer this way to me.

That is just one particular kind of Balun. And yes that is a Balun. But there are many MANY other types of baluns and transformers used for audio and video. Just because some schmoe at Radio Shack doesn't know what they are doesn't mean they don't exist.

Just google "audio balun" or "video balun" and you'll have hundreds of choices from endless vendors and manufacturers.

No, it show that he knows why the wires are twisted together in a balanced interconnect. You, clearly, still don't get this.




You're simply incorrect in your understanding of the oldest method of transmitting audio signals.

The links support my assertions. I have asked you this before with endless silence being the result but will try again anyways: Do you have anything at all more credible than something you pulled out of your a**?

I said a balun was a transformer, and it is.

Yes, as did I and many others.
You implied that a BaLun is only used for RF signals, you were corrected.

A balun typically used to connect a dipole antenna to a 75R transmission line, will not work as an audio transformer in any useful way.

...but still don't understand.

Just because some schmoe at Radio Shack doesn't know what they are doesn't mean they don't exist.


...or thinks they can only be used at RF.

Ridiculous. There are scores of audio transformers out there, and that's really all Baluns are at the end of the day. There are baluns designed for different bandwidths and different tasks (such as video baluns for instance, digital audio, etc). But there certainly are analog audio baluns of various types from various manufacturers. I've used scores of them.
It is not ridiculous at all, and your point about bandwidths and correct usage actually proves the point I was trying to make: use the correct device for the job. An RF balun will only be useful for audio transmission over Cat cables if it is in the digital domain or on a carrier. Use a quality Jensen et al transformer designed for line level AF band transmission.

I was an RF engineer for many years and did live sound also. I only ever heard 'balun' used in RF.

Perhaps this a common US usage.

Do you have anything at all more credible than something you pulled out of your a**?

I don't bother trying to explain anything to you, because you don't have the ability to understand anything, as you've clearly demonstrated in this thread.

That is just one particular kind of Balun. And yes that is a Balun. But there are many MANY other types of baluns and transformers used for audio and video. Just because some schmoe at Radio Shack doesn't know what they are doesn't mean they don't exist.

Just google "audio balun" or "video balun" and you'll have hundreds of choices from endless vendors and manufacturers.And there are many people here who also wouldn't know the difference and would walk out with what I showed a pic of and wonder why it doesn't work at AF.

I only ever heard 'balun' used in RF.

well now you know better. as mentioned many times, a BaLun converts balanced to ubalanced, weather it's RF, audio video or power.

I was an RF engineer for many years and did live sound also.

...and you never thought to ask someone what this acronym meant?

And there are many people here who also wouldn't know the difference and would walk out with what I showed a pic of and wonder why it doesn't work at AF.

Apparently, you're one of them.

Your first statement shows you don't understand the nature of noise induced by external fields onto a conductor, how impedances, and wire geometry play a part in how this noise energy manifests itself.

I will try to help: balanced vs unbalanced - deals with impedances. differential vs single ended - deals with the nature of the signals themselves, specifically their voltages.

You aren't helping anything except making a confusing mess out of not an enormously difficult subject. Balanced vs unbalanced doesn't have anything to do with the impedance of the cabling, but the impedance of the conductors relative to ground. As I pointed out before, and which you seem to have backtracked on, is that a balanced line is not necessarily a differential line, but can be. This is probably a step too complicated for you, and it isn't hugely relevant for the noise rejection discussion. Whether the signals are symmetrically opposed or not doesn't have any impact at all on the noise rejection of a balanced line because the noise will be equal and opposite, and if the conductor impedance to ground is equal and the noise is induced equally and the conductor length are equal, the noise will cancel out, regardless of what the signal on the line is doing which is irrelevant.

There are particularly good wire geometries to use in a balanced line which achieves as close to equal noise induction on both conductors as possible, and that is paired conductors that are as close together as possible, and twisted together to hold them close together and help maintain equal noise induction into both conductors. The twist also helps maintain the cabling impedance stability which isn't really relevant for the noise induction but is relevant for the signal. A particularly horrible cable to use for a balanced line would be coaxial cable because the impedances to ground of the two conductors are totally different, as are their geometry, and because one of the conductors is designed as a shield, it will make noise rejection not work nearly at all because the noise will no longer be common to both conductors. Coax is designed and excellent for unbalanced transmission, twisted pair is designed and excellent for balanced transmission. There are also many shielded paired cables that are also excellent for unbalanced transmission, but you'll also notice that they often aren't tightly twisted if at all, because the twist isn't relevant unless you are using a balanced line.


Wire geometry - deals with EM theory of the systems interaction with itself and surrounding environment. To say that any of these things are necessarily related would be technically incorrect per the definitions of each of them regardless of existing industry trends.

Again, I'm not clear what you're saying here.

It's really quite simple: balanced line you use twisted pair. Twisted pair doesn't do anything for you unless its a balanced line.

Unbalanced line: you are relying on shielding, so use heavily shielded cable, either a shielded paired cable or a coax type cable.

...and you never thought to ask someone what this acronym meant?
Grow a brain, of course I knew what it meant, but you obviously like to be a smartarse and selectively quote. I have now made more than one post where I said I think the misunderstanding is because of different usage in different parts of the world.

I don't bother trying to explain anything to you, because you don't have the ability to understand anything, as you've clearly demonstrated in this thread.

Now there is a strong argument. lol!

OK, assuming for a moment that were true...

What is your excuse for pretending to show up here trying to be useful to the OP's plight but not explaining these potential points of confusion?

I have little doubt I know the answer to that. lol!

Grow a brain,

Wow, you're a tough one!

you posted the same thing over and over, demonstrating that you don't have much of a clue.

It is not ridiculous at all, and your point about bandwidths and correct usage actually proves the point I was trying to make: use the correct device for the job. An RF balun will only be useful for audio transmission over Cat cables if it is in the digital domain or on a carrier. Use a quality Jensen et al transformer designed for line level AF band transmission.

I was an RF engineer for many years and did live sound also. I only ever heard 'balun' used in RF.

Perhaps this a common US usage.

Okay, well just because you've never heard of something doesn't mean it doesn't exist or isn't commonly used. As already pointed out obviously an RF balun is totally inappropriate to use.

Here's just a handful of AV baluns for various uses:

http://www.etslan.com/AudioVideo.htm
http://www.intelix.com/products/balun_audio.htm
http://www.muxlab.com/products/ve_avd_s-av_balun.html


And there are countless more.

You are wrongly limiting the term Balun to mean only one specific and particular type of balun you are familiar with, but there are many many other kinds out there.

Not all baluns are created equally. All types available. Get the right balun based on your wiring to retrofit.

IMHO, just use the designated cabling/wiring for the application. ;)

Wow, you're a tough one!

you posted the same thing over and over, demonstrating that you don't have much of a clue.Bollocks, go back and re-read, rather that just selectively quoting. You just want to be a smartarse because of a terminology difference. I have explained why, but simply taking cheap shots seems to be about all you want to do. The term came from RF, and that is it's most common usage here in my experience.

OK, assuming for a moment that were true...

no need to assume.

What is your excuse for pretending to show up here trying to be useful to the OP's plight but not explaining these potential points of confusion?


You're obviously angry that you've been schooled.
When you were corrected two pages ago, you retorted with a lot of garbage, proving that you don't know what you're talking about. You've been corrected a number of times since, yet still come back to this nonesense.

The term came from RF,

Again, no it didn't.

Below the equator, they work in reverse. They are called UNBAL's. LOL!!!

You are wrongly limiting the term Balun to mean only one specific and particular type of balun you are familiar with, but there are many many other kinds out there.In the same way that you are incorrect to assume that a term in common usage where you are is universal everywhere else.

Look Chris, I'm tired of responding to your statements in which you try to put words in my mouth, which posted evidence would support, I never said. You clearly have some gaping holes when it comes to knowing the theory behind this stuff.

For example does this statement you made

Balanced vs unbalanced doesn't have anything to do with the impedance of the cabling, but the impedance of the conductors relative to ground.

somehow contradict mine which you felt the need to spend a paragraph addressing:

balanced vs unbalanced - deals with impedances.

Then you said this:

As I pointed out before, and which you seem to have backtracked on, is that a balanced line is not necessarily a differential line, but can be.

Either you never read my response to your post or you like dwelling on the past but I conceded your point on this many many posts ago. Give it up already.

You really seem to be struggling hard to point me out as being the devil and yet have not supporting evidence contradicting anything about my last post other than the school of Duvetynes hand waving.

Again, I'm not clear what you're saying here.

It's really quite simple: balanced line you use twisted pair. Twisted pair doesn't do anything for you unless its a balanced line.

Unbalanced line: you are relying on shielding, so use heavily shielded cable, either a shielded paired cable or a coax type cable.

This is precisely what I'm reffering to when I suggest you don't get it. You should look at the link about UTP on wiki. Twisted pair does help in unbalanced circuits because it reduces differential noise. Maybe you should ask yourself if you've ever heard of a perfect ground before? They all have impedance which can and will be modulated by noise. Differential noise is a problem for unbalanced circuits too.

Bottom line is I have better things to do than go round and round about this stuff repeating myself. You clearly have some learning to do and don't appear to be willing to even listen to reason. The links are there, now you need to understand whats in them.

no need to assume.



You're obviously angry that you've been schooled.
When you were corrected two pages ago, you retorted with a lot of garbage, proving that you don't know what you're talking about. You've been corrected a number of times since, yet still come back to this nonesense.

Typical and worthless as ever.

Look Chris, I'm tired of responding to your statements in which you try to put words in my mouth, which posted evidence would support, I never said. You clearly have some gaping holes when it comes to knowing the theory behind this stuff.

And I've kept asking you to point out what exactly you disagree with, and you can't do that, you just keep saying I don't know what I'm talking about and I can't really discern what it is you have a problem with.



For example does this statement you made



somehow contradict mine which you felt the need to spend a paragraph addressing:



Then you said this:

That's because your statements are confusing, unclear, and I don't really know what it is your disagreement is even about.


Either you never read my response to your post or you like dwelling on the past but I conceded your point on this many many posts ago. Give it up already.

I did, but you are incoherent, so it's difficult to figure out what the heck you mean particularly when you are confusing so many things together.


You really seem to be struggling hard to point me out as being the devil and yet have not supporting evidence contradicting anything about my last post other than the school of Duvetynes hand waving.

I have no idea where you get that. I'm just attempting to explain the subject, briefly.



This is precisely what I'm reffering to when I suggest you don't get it. You should look at the link about UTP on wiki. Twisted pair does help in unbalanced circuits because it reduces differential noise.

No it doesn't. In an unbalanced circuit, one leg is ground. There is no common noise possible so there is no noise cancellation. How can it cancel out in an unbalanced circuit? The answer is that it can't, and that it doesn't, and that's why twisted pair doesn't do you a damn bit of good unless the circuit is balanced.

As for the links, I'm not sure what it is you are referring to that supports your idea that twisting the pair together somehow reduces noise by and of itself. It doesn't. It only helps if it is a balanced line. The Wikipedia article, rough as it is, does an alright job of explaining this. If you have an unbalanced line, there won't be any difference if you have an untwisted pair or a twisted pair, because the twist is only advantageous for common mode noise rejection which obviously only can occur in a balanced line.


Maybe you should ask yourself if you've ever heard of a perfect ground before?

I don't understand what you mean by this question. Do you mean too much resistance to ground? I'm not sure the relevance of what you are asking here.

They all have impedance which can and will be modulated by noise.

Again, what? What has impedance modulated by noise? This makes no sense at all.


Differential noise is a problem for unbalanced circuits too.

Okay...?


Bottom line is I have better things to do than go round and round about this stuff repeating myself. You clearly have some learning to do and don't appear to be willing to even listen to reason. The links are there, now you need to understand whats in them.

What links? What reason? You haven't even said anything that makes sense! The reason you're going around and around is because you're not constructing any kind of linear point here.

I fail to see why this topic is so difficult for you to understand. The pair twist only exists to make sure that noise is induced equally on both conductors, and the only reason this is beneficial is if it's a balanced line so it can cancel out. If it's not balanced, well then obviously is isn't going to cancel out is it! So the twist has no advantage at all! That's all I've been saying since page one, and apparently you can't accept this very simple premise. That's why you almost never see unshielded twisted pairs in anything but balanced lines, or for higher level signals where noise is not a concern.

And in the words of Stephen Lampen of Belden:

The most common type of paired cable run in unbalanced mode is speaker cable. ... Speaker cables are not balanced lines. And no matter how beautifully the two conductors might be twisted together, there is no common-mode noise rejection accomplished.

They all have impedance which can and will be modulated by noise.

LOL...you're the 'expert'.

Typical and worthless as ever.

Good of you to finally admit it ;)

I never thought there would be so much confusion and misinformation floating around about balanced pairs, unbalanced lines and balun systems.

First, as several folks correctly stated baluns are available to convert any signal type from audio to baseband video to RF to digital from one type of connection/transmission format to another. Unbalanced to balanced and back again.

Baluns were NEVER solely in the domain of 300 hm to 75 ohm RF antenna cabling. Baluns are nothing more than transformers with the primary and secondary windings connected differently with reference to signal ground.

One winding has one end of its coil tied to a signal common (not necessarily electrical ground) the other is the phase end which connects to the active circuitry I/O. The other winding has neither side of the coil tied directly to the signal common. The secondary coil does not NEED a common or ground reference to function.

The structure of these coils varies according to the signal source, bandwidth, impedance, frequency, and amplitude. It can be a ferrite donut or iron (steel) laminated core.

No matter what the signal source, the concept of a balun is the same.

Almost 50 years ago. Bogen sold a small balun transformer called the WMT-1. It had an RCA male cable on one side of a small metal box and screw terminals on the other. It was used to connect a Hi-z single ended (unbalanced) bridging signal from one amp, through a UTP cable to the same configuration on the other end. It worked fine for thousands of installs.

It sounds like a 50 year old, simple gadget would easily fill the bill for the OP.

I always thought "transformers" where always powered? Baluns are not powered. Of course I dont not care one bit about any of the discussion. I just know they work.

I always thought "transformers" where always powered? Baluns are not powered. Of course I dont not care one bit about any of the discussion. I just know they work.

No definitely not. All a transformer is really is a pair of coils, in its simplest conception.

No definitely not. All a transformer is really is a pair of coils, in its simplest conception.

I figured that after reading some of the dicussion....never thought much about it, I have a very simplistic view of transformers.

I have a very simplistic view of transformers

they're very simple, passive devices.

Baluns refer to the transmission format change. There are dozens of different types and many are strictly passive sucgh as the 300/75 RF balun that was pictured earlier.

Transformers are wonderful devices, that is true, simple, to the point and I love em!

One audio transformer can frequently be used in place of a full bottle of Excedrin and several beers in many situations.

BTW if you look at the RF balun pictured earlier, it clearly says MATCHING TRANSFORMER.

And I've kept asking you to point out what exactly you disagree with, and you can't do that, you just keep saying I don't know what I'm talking about and I can't really discern what it is you have a problem with.

Clearly I am and have been disagreeing with your insistence twisted pairs can only reduce noise to balanced circuits.

Again from the UTP link.

Twisted pair cabling is a form of wiring in which two conductors (the forward and return conductors of a single circuit) are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources;

Note that there is nothing whatsoever about balanced impedances or signal types. Very very clear IMO.

That's because your statements are confusing, unclear, and I don't really know what it is your disagreement is even about.

I was thinking the same thing about you especially when you basically repeat what I said for two paragraphs but in an argumentative tone as if we disagreed.

I did, but you are incoherent, so it's difficult to figure out what the heck you mean particularly when you are confusing so many things together.


Exactly what is it about my statement "I do, however, concede this point." that confuses you? The text seems simple to understand to me and rather straight forward.

No it doesn't. In an unbalanced circuit, one leg is ground. There is no common noise possible so there is no noise cancellation. How can it cancel out in an unbalanced circuit? The answer is that it can't, and that it doesn't, and that's why twisted pair doesn't do you a damn bit of good unless the circuit is balanced.

The amount of noise energy recieved by the cabling depends on the conductors geometry within the noise fields. The only effect the circuits impedance has is how this energy manifests itself as noise voltage at the transciever pins. The impedance cannot somehow magically deny the noise energy entrance to the circuit. It can only vary it's resulting voltage magnitude as seen at the transciever which may or may not allow this circuit to more effectively deal with it. Denying noise energy from entering the circuit in the first place via choice of good wire geometry benefits every circuit type.

It's really great and useful that balanced circuitry deals with certain types of noise more elegantly than unbalanced circuitry but that is completely beside the point.

I have no idea where you get that. I'm just attempting to explain the subject, briefly.

Could it be those examples such as where I pointed out above you spend 2 paragraphs agreeing in an argumentative way?

I don't understand what you mean by this question. Do you mean too much resistance to ground?

Grounds all have impedance which will have a voltage due to noise current travelling through it. No system has a perfect no impedance ground, not even really well designed circuits.

Again, what? What has impedance modulated by noise? This makes no sense at all.

I'm not suprised by the idea that you can't fathom ground impedance being modulated by noise current.

Okay...?

It follows logically that steps to reduce it are good.

Clearly I am and have been disagreeing with your insistence twisted pairs can only reduce noise to balanced circuits.

Again from the UTP link.

Note that there is nothing whatsoever about balanced impedances or signal types. Very very clear IMO.



You are completely abusing that quotation. The entire reason the noise is rejected is BECAUSE it's balanced. That's the whole point I've been repeating and I cited Stephen Lampen at Belden above, which you ignore.

Since you believe that twisting a pair of conductors somehow rejects noise from external sources(other than crosstalk from neighboring pairs in a multipair cable), why don't you explain the magical principles by which this is accomplished?

Twisting the pairs doesn't do anything UNLESS it's a balanced line. Period. Stop inventing physics out of ignorance.

I'm not suprised by the idea that you can't fathom ground impedance being modulated by noise current.

I'm not surprised that you'd refuse to explain this, however, I am curious to find out how current can alter the resistance, capacitive and inductive reactance of a conductor.

You are completely abusing that quotation.

I am? You are the one insisting on adding words to it not in there.

That's the whole point I've been repeating and I cited Stephen Lampen at Belden above, which you ignore.

The one where he mentions it won't offer common mode noise rejection like I've been saying? The problem is differential signals that these circuits are designed to respond to.

Since you believe that twisting a pair of conductors somehow rejects noise from external sources(other than crosstalk from neighboring pairs in a multipair cable), why don't you explain the magical principles by which this is accomplished?

I have several times now. As I said before it's getting old repeating myself. At least I'm reading wht you write even if I disagree with some of it.

Twisting the pairs doesn't do anything UNLESS it's a balanced line. Period. Stop inventing physics out of ignorance.

No you stop. You are the one who can't seem to come up with anything other than I said so.

Edit: You may want to investigate what a loop antenna is and what it does. I think it will help you understand what is being discussed. I already mentioned this many posts back but you seem to be having trouble reading or comprehending what has been written.

I'm not surprised that you'd refuse to explain this, however, I am curious to find out how current can alter the resistance, capacitive and inductive reactance of a conductor.

I'm not sure what is so complicated here.

An impedance with a current through it will have an associated voltage across it. You may want to check out ohms law if this seems hard to understand.

All grounds no matter how well designed have impedances built in.

I'm not sure what is so complicated here.

me neither.

An impedance with a current through it will have an associated voltage across it.

your first correct remark, bravo!

You may want to check out ohms law if this seems hard to understand.

perhaps you should...show me where Ohm says that reisitance, capacitive and inductive reactance is changed by current.

All grounds no matter how well designed have impedances built in.

You've completely avoided the question.

Tell us how impedance is modulated by current, as you previously stated.

I'm guessing that you don't know what impedance is, or what modulation means.

Tell us how impedance is modulated by current, as you previously stated.

Ah the nitpicker approach to non-debate by attacking minor and irrelevant points.

OK einstein I get what your problem is. I probably should have said something like the noise current energy across the ground impedance modulates the voltage seen at the transciever interfaces as I explained in detail earlier. Feel better?

Excuse me for getting a little sloppy on the thousandth time we've gone back to the same idea.

Seriously man, is this the highest level of debate you offer? Kind of sad really. I guess at least you are trying to get into the technical side of the discussion now. How about an actual on topic post? That would be a hell of a step for you.

All you can do is attack...you don't understand balanced/differential signalling, and you don't seem capable of learning.
It's been explained to you numerous times yet you continue to repeat the same BS.
This is basic stuff....no need to get into the more complex stuff that you clearly won't understand until you've got the basics down.

OK einstein I get what your problem is.

...and we all see what yours is.

Excuse me for getting a little sloppy

no, if you're going to pretend to be an expert, don't be sloppy....don't cry wolf either, as you often do.

I guess at least you are trying to get into the technical side of the discussion now.

And I see you've managed to stay out of all technical discussion , and offer your uninformed opinions instead ;)

All you can do is attack.

Wow, coming from you this is almost laughable.

Of course you are incorrect as usual. In my first post way back on page one I explained about the benefits of reducing loop antenna area by twisting. I don't even want to go back and count how many times I've repeated this point. None of you who is disagreeing seems willing to address this point though. There are many many attacks on me and everything I've written but none of you geniuses can put together a coherent argument regarding the actually relevant point. Lot's of blah blah blah about differential this and balanced that but only one other person has addressed the affect I have been speaking of all along and this person would seem to agree with what I'm saying based on their post.

So duvetyne why don't you explain, if you are so sure of yourself, why reducing the loop antenna effect of the signal conducting wires does not reduce the amount of noise energy injected to the circuit?

I keep asking you to do this. Of course you wont/don't even try since you obviously have nothing. What I do expect from you is more character attacks and irrelevant nitpicking. You say you are here to help but yet can't come up with a good expalnation for your POV? Seems a more than a little fishy.

I am? You are the one insisting on adding words to it not in there.



The one where he mentions it won't offer common mode noise rejection like I've been saying? The problem is differential signals that these circuits are designed to respond to.

You just said above that twisted pairs reject noise even if the line is not a balanced line. THAT IS NOT TRUE. If a twisted pair rejects noise in some other way than common mode noise rejection on a balanced line, please come out with it. But you can't, because you don't have a clue what you're talking about, and it doesn't.

The quote that you cited doesn't say that it does, it just makes the vague statement that twisted pairs help reject noise better, and this is true only on a balanced line, which is something that the statement did not say explicitly because it assumes that you're not an idiot and know how it is that twisting the pairs is beneficial. The way that it is beneficial is to reject common mode noise on each conductor, which is what happens with a balanced line. This doesn't happen on an unbalanced line which is why twisting the pairs is not beneficial on a balanced line which is what I've been saying since the first page.

As for your statement that "The problem is differential signals that these circuits are designed to respond to" again that is a completely nonsensical statement. The differential signals are a problem? What the heck are you talking about?


I have several times now. As I said before it's getting old repeating myself. At least I'm reading wht you write even if I disagree with some of it.


Please cite me one time you explained how an unbalanced twisted pair accomplishes noise rejection.


No you stop. You are the one who can't seem to come up with anything other than I said so.

The wikipedia article explains it, as did Lampen from Belden, as did the article from Kurt at Blue Jeans cable.

Here are some more explanations of how a twisted pair rejects noise on a balanced line:

http://www.maxim-ic.com/appnotes.cfm/an_pk/2045

http://www.epanorama.net/documents/wiring/twistedpair.html


Edit: You may want to investigate what a loop antenna is and what it does. I think it will help you understand what is being discussed. I already mentioned this many posts back but you seem to be having trouble reading or comprehending what has been written.

I have no desire to investigate loop antennas because it isn't relevant to this topic.

duvytyne is far more blunt than I, but he is right in that clearly you haven't a damn clue what you're talking about.

I'm not sure what is so complicated here.

An impedance with a current through it will have an associated voltage across it. You may want to check out ohms law if this seems hard to understand.

All grounds no matter how well designed have impedances built in.

Right. But that's not what you said. You claimed that voltage would change the impedance or the resistance. How this is relevant to this discussion I do not know. Small amounts of current not have any meaningful effect on this at all such as from noise which is what you mentioned.

So you said something that was completely bogus BS that you hadn't a clue about, and then you pretend that you said something else entirely which is basically an idiots version of ohms law. Nice. :rolleyes:

Ah the nitpicker approach to non-debate by attacking minor and irrelevant points.

OK einstein I get what your problem is. I probably should have said something like the noise current energy across the ground impedance modulates the voltage seen at the transciever interfaces as I explained in detail earlier. Feel better?

Excuse me for getting a little sloppy on the thousandth time we've gone back to the same idea.

Seriously man, is this the highest level of debate you offer? Kind of sad really. I guess at least you are trying to get into the technical side of the discussion now. How about an actual on topic post? That would be a hell of a step for you.

That's a "little bit sloppy?" That's more like a dental hygienist who amputates your legs and goes "oh gee, you're just nitpicking I was being a little sloppy."

Hilarious. You claimed two totally BS things, one of which was that twisting conductors somehow rejects noise in an unbalanced configuration (nonsense). The other was that small noise current through a ground conductor or any conductor would change its impedance (also complete ********).

And your only explanation for these claims appears to be "read about loop antennas!"

That's a "little bit sloppy?"

IMO yes, especially compared to you avoiding the subject the entire conversation. I explained it first then followed up with some sloppy wording when asked repeat myself continuously. Of course you can't address the actual point of the message and keep nitpicking. :rolleyes:

And your only explanation for these claims appears to be "read about loop antennas!"

Yes as has been obvious since page one. Considering it is precisely the point I have been arguing the whole time it seems relevant. Care to address this little point? I see you are very good at finding new ways to avoid addressing this as evidenced by your repeated attempts to point out mistakes I've made in my wording.

Will Wiggles ever address the actual point or will he continue his ultra effective technique of ignoring it entirely but focusing on the irrelevant?

Edit: BTW there are many many links that tell about what happens when you form a loop with a conductor, with impedances in there. A well known phenomenon, I'm suprised you are this ignorrant of it.
Bet I know the answer...four pages later.

Will Wiggles ever address the actual point or will he continue his ultra effective technique of ignoring it entirely but focusing on the irrelevant?

Do you know what irony means?

Do you know what irony means?

Avoiding the subject again? I'm shocked.

Question while you bicker...
How well does cat5/6 work for audio/video without baluns (or transformers)?

Pretty crappy. You get signal reflections from the impedance mismatch, and induced noise from lack of shielding.

Avoiding the subject again?

So the answer is no, you don't know what irony means.

So the answer is no, you don't know what irony means.

Avoiding the subject again? I'm shocked.

Question while you bicker...
How well does cat5/6 work for audio/video without baluns (or transformers)?

Terribly seeing as how it isn't shielded so you'll have horrible noise issues if there's noise in the environment, and for digital audio and video where impedance is a concern you'll get reflections which are no good either.

It can be done though, I've done it before, with the expected bad results. But if that's all you have there, and no baluns...

IMO yes, especially compared to you avoiding the subject the entire conversation. I explained it first then followed up with some sloppy wording when asked repeat myself continuously. Of course you can't address the actual point of the message and keep nitpicking. :rolleyes:


I missed you making any kind of a point in that message, or really in any other message in this thread.


Yes as has been obvious since page one. Considering it is precisely the point I have been arguing the whole time it seems relevant. Care to address this little point? I see you are very good at finding new ways to avoid addressing this as evidenced by your repeated attempts to point out mistakes I've made in my wording.

No I won't adresss this point because: 1) you haven't made a point 2) twisting the conductors together doesn't change anything about how they may act as an antenna and 3) you're a fool.


Will Wiggles ever address the actual point or will he continue his ultra effective technique of ignoring it entirely but focusing on the irrelevant?

Edit: BTW there are many many links that tell about what happens when you form a loop with a conductor, with impedances in there. A well known phenomenon, I'm suprised you are this ignorrant of it.
Bet I know the answer...four pages later.

WHAT POINT!? What the f**k are you talking about!? WHAT link?

If you have a point, COME OUT WITH IT. If not, bugger off, twisting the conductors together doesn't make a damn bit of difference unless the line is balanced. This is a completely noncontroversial statement, and if you're too stupid, ignorant, and stubborn to recognize it, then I'm not going to waste my time with your idiotic claims about loop antennas which have nothing to do with anything.

I missed you making any kind of a point in that message, or really in any other message in this thread.

Your lack of reading comprehension skills is very apparent at this point. From my first post in this thread, post #5:

"The act of twisting the wires extremely reduces the current loop areas (read reduce antenna efficiency) and does wonders for detuning these cables to the ability to resonate (form standing waves) in the presence local ambient EMI noise field energy."

I've repeated this smae idea numerous times to you now. Keep avoiding the subject.

No I won't adresss this point because: 1) you haven't made a point 2) twisting the conductors together doesn't change anything about how they may act as an antenna and 3) you're a fool.

1. clearly the point has been made by me and others numerous times, lord knows why you haven't noticed or keep trying to avoid it 2. anybody who knows anything about loop antennae knows that decreasing loop area is proportional to it's gain 3. you are the fool and are now acting like a jerk too.

WHAT POINT!? What the f**k are you talking about!? WHAT link?

The one that has been made many times by me now and also others in this thread. You might try google.

heres a good place to start (http://en.wikipedia.org/wiki/Loop_antenna)

If you have a point, COME OUT WITH IT.

Again? Really, come on. I've already repeated myself too many times to even bother counting. Yours is clearly a lost cause since you seem to be under the impression you know everything but unfortunately stopped learning well short of the mark necessary to speak of these things.

twisting the conductors together doesn't make a damn bit of difference unless the line is balanced.


------------

Please check off the answers that apply from the following list:

(1) I never took a course in transmission lines in college, so my lack of proper understanding of twisted pair transmission lines is understandable.

(2) I have never done any significant projects with transmission lines, so my lack of proper understanding of twisted pair transmission lines is understandable.

(3) I don't know how to search google for articles about how transmission lines work, so my proper understanding of twisted pair transmission lines is understandable.

----------

Just in case my lame attempt of humor somehow flies over your head or under your feet...

The area inside a loop of wire strongly determines how it works as an antenna or secondary of a transformer.

One of the benefits of twisted pair is that like coax construction, it goes a long way towards reducing the area inside the loop until it is vanishling small.

The line need not be balanced for twisting the wires to be very helpful when it comes to picking up interferance from external sources. Since the power lines in your home and business are not intentionally desighed to be coax or twisted pair, they radiate wonderful magnetic fields and are very willing to act as the primary of a transformer.

First, Chris is right about balanced lines where NEITHER line of the balanced pair is tied to signal common as the only definition of a balanced signal line, by the very definition of the term balanced. The other option is unbalanced where by definition and circuit design, the signal is tied on one side of the path to signal common.

I would love to have seen one single example of an audio or video device that uses a single ended I/O connection and refers to it as balanced.

It is either balanced with no signal ground connection in order to function or unbalanced with signal ground as the return.

No gray area. No noise cancellation is possible with a UTP configured as a single ended xmission line with one phase and one signal common connection. This is precisely why shielding on single ended circuits is so important and why the best shielding fully encompassed the phase conductor in a foil or tightly braided wrap. If any part of the phase conductor is not shielded as would be the case in a UTP configured as an unbalanced xmission line, noise can easily take advantage of the "antenna effect".

This is precisely why cheaply made shielded cables with loose or non-uniform and tightly constructed shields can go "microphonic". In video, you end up with ghosting and other artifacts.

If someone wishes to refute this in a real manner, post the device Manufacturer and model so that we all may revel in the magic of such a device.

We should then contact all the shielded wire and XLR manufacturers, and transformer manufacturers and thank them for years of dedicated service but it has been determined here that the physics applied to the electronics industry and AV in particular for the last 80 years have been in error. We will no longer be needing their services.

And then you woke up.

No gray area.

Agreed.

No noise cancellation is possible with a UTP configured as a single ended xmission line with one phase and one signal common connection.

Disagreed.

One can unravel a twisted pair and form the two conductors into the shape of a circular loop. The bigger the loop the more frequencies it can recieve, and the more efficiently it will do so. This configuration is guaranteed to recieve more noise from ambient noise fields of the correct orientation and frequencies that the loop is tuned to as compared to when the conductors were twisted together. Twisting the pairs minimizes loop area of any potential antennae, thus detuning them to potential noise sources by reducing the range of frequencies the loop can physically recieve and the sensitivity to the field strength of potential noise sources by reducing gain.

The impedance of the circuit does not affect antenna gain or the frequencies it may recieve. The impedance only affects how the noise energy current manifests itself as a voltage where it counts: usually the recieve end but if these voltages end up being large enough active electronic transmitters can certainly be affected negatively as well. The impedance presented by the loads and sources and even the lines themselves determine whether the antenna has a balanced impedance which determines the fidelity of the recieved signal. True that an unbalanced antenna could not be used for high fidelity radio work, but who cares in this case? The question is whether the noise is there at all, not if it is distorted.

In summary: the circuits geometry is related to it's effectivity as an antenna by determining it's frequency response and field sensitivity. Its distributed impedance characteristics determines the fidelity of any recieved signal/s.

Edit:

We should then contact all the shielded wire and XLR manufacturers, and transformer manufacturers and thank them for years of dedicated service but it has been determined here that the physics applied to the electronics industry and AV in particular for the last 80 years have been in error. We will no longer be needing their services.

Who said anything about shielding not being effective or having it's place?

No matter how tightly you twist a pair of wires, there is no resultant drop in inducted noise on that line IF the line is configured as single ended I/O. There is essentially no area of the phase wire that is not exposed.

Before the development and use of balancing transformers for microphones. the standing rule of thumb for mic cable length from the mic element itself to the control apparatus was 30 ft. Much past 30 ft and there was a plethora of noise and radio reception etc that was easily picked up on unbalanced cables due to the antenna effect. The advent of fully balanced cables and transformers eliminated that problem.

Today's mic elements are still single ended with respect to the phase and signal common, but the xmission lines are balanced. Problem solved.

I have run base band video and audio over standard mic cables and UTP premise wiring using active and passive baluns from floor to floor and between buildings for hundreds of feet with no problems at all.

Not possible to do that with UTP wiring connected as a single ended (common/phase) wiring configuration no matter what the twist is.

Before the development and use of balancing transformers for microphones.

I don't doubt it one bit. No one is saying balanced lines don't help with noise problems.

The relevant point here is that twisted or tightly spaced parallel wires got you to the 30 foot limit you mention. Unravelling and maximizing loop area would have reduced the limit even further than thirty feet in high noise environements. The fact that most of us are running unbalanced single ended setups with no transformers etc means this twisting is relevant to these systems in a big way.

I just twisted my telephone wire (RJ11) and now I hear a radio station on my phone! :)

C'mon baby! Let's do the twist...

The cables used were single ended, spiral wrapped shielded cables. Identical in design to the cheap little RCA cables of today. Once the concept of transformers balancing the lines and extending the usable cable lengthwas understood and accepted, 3 pin ITT /Cannon connectors (precursor to XLRs of today) were used. The pin configuration was the same as today, albeit much larger.

Transformers were incorporated in the microphone housing and added to existing audio equipment. This allowed the close proximity of several cables of similar and different source material.

I have seen a few times over my rather long career where someone TRIED the TP concept for a single ended I/O but it never works. in the real world.

BTW I grew up in the AV industry from the early 60's and my dad put several TV stations on the air including the ABC station in DC WJAL formerly WMAL and four other TV stations in Fort Wayne, Indiana, and Parkersburg, WV.

I have seen and worked with the evolution of sound systems and cabling for many years all over the country, so I have been intimately involved with this for many moons.

POTS is the oldest "electronic audio system" in existence, it uses a differential audio connection between central office and each telephone.
ITT/Canon XLR connectors were originally developed as AC power connectors.

I have seen and worked with the evolution of sound systems and cabling for many years all over the country, so I have been intimately involved with this for many moons.

I'm sure your many moons have yielded much valuble experience however if none of the systems you have experience with is equivalent to the loop I described it is irrelevant to the discussion at hand. This would appear to be the case per your description of your experience. None of the systems you describe maximizes loop area to make the resulting antenna effect gross and obvious enough to really be noticeable in a typical ambient EM environment.

Cheap RCA cables bundle the plus and minus conductors in the same cable housing minimizing loop area even if it is not twisted within the housing. This is also true with the mic cords and XLR cables I have seen.

Bottom line is because you haven't noticed the effect using industry standard cabling designed to minimize it is certainly no proof it does not exist.

Since UTP data cable is most effective when used in conjunction with the differential ckt for common-mode noise rejection, do all NICs, routers, hubs, etc. on our computer ntwk have differential ckt for data x'mission? Or it is not needed due to Packet switching mode? Can someone shed some light? Thanks.

do all NICs, routers, hubs, etc. on our computer ntwk have differential ckt for data x'mission?

Yes, it's the transformer present on all NICs and Network ports.

Since UTP data cable is most effective when used in conjunction with the differential ckt for common-mode noise rejection, do all NICs, routers, hubs, etc. on our computer ntwk have differential ckt for data x'mission? Or it is not needed due to Packet switching mode? Can someone shed some light? Thanks.

I can only speak to the designs I've been involved with or products I'm aware of. All that I have experience wih use differential signaling on the ehternet side.

Yes, it's the transformer present on all NICs and Network ports.

The phys I'm familair with send/recieve differential signals whether the transformers are present or not.

Those of us who work with line and mic level signals day in and day out know that UTP cable can easily be used and IS used with balun systems for problem free, long distance xmission of these signals. in hundreds of thousands of installations all over the world.

You are attempting to introduce claims into the discussion that are simply not backed up in the real world or germane to the OPs question. I have asked you to post a single installation or device that uses UTP in a single ended, unbalanced configuration for audio or baseband video xmission and I am still waiting.

You are attempting to introduce claims into the discussion that are simply not backed up in the real world or germane to the OPs question. I have asked you to post a single installation or device that uses UTP in a single ended, unbalanced configuration for audio or baseband video xmission and I am still waiting.

A theoretical discussion of how UTP may be beneficial as compared to other theoretically possible implementations of cables absolutely is germane to the OP's question. I happen to prefer to take a wider view of the world which includes the possibility of non standard cabling being used. It is the preferred engineering approach as opposed to jumping to conclusions which may or may not be valid. The OP never mentioned which cables to compare the UTP with and so not jumping to conclusions about which type he prefers them be compared with makes sense.

I'm not sure what you expect from me regarding posting an example. I stated originally that I have heard there are some who like using it. I don't have any pictures of an instance since it is not something I've tried and am simply not exposed to many, if any, other installations than my own. You might take up your disagreement with someone who actually thinks the benefits of UTP are necessary in their system. I have not found cables to be the most pressing issue with my own system and so have not taken the time to try cables which I've theorized will offer improvements over what I use now. Someday perhaps I will get the time to try some UTP, STP, coax etc.

All that I have experience wih use differential signaling on the ehternet side.

is there another side?
All ethernet over TP uses differential signalling, it's a standard.

is there another side?
All ethernet over TP uses differential signalling, it's a standard.

Of course, the cpu/mac side...typically single ended.

Of course, the cpu/mac side...typically single ended.

Correct, internal TTL like communications is typically single ended, just like internal signalling in most audio and video equipment, and pretty much everything else.
Not that it has any bearing on the topic, but since you brought it up, a PCI express NIC communicates within the PC over a differential serial bus....not everything is single ended, as you claim.

There is no more flesh on this horse.

a PCI express NIC communicates within the PC over a differential serial bus....not everything is single ended, as you claim.

I did say "typically" as in not always. My world is embedded products with no backplanes and no need for PCI. You would have a good point though if you were to say that PC's using PCI are a significant market which I suppose would logically employ mac/phys using the signaling of whatever bus they are expected to be used with. Not my world though so I really can't comment on that. Maybe "typically" was too strong a word and should have been replaced with "sometimes".

My world is embedded products with no backplanes and no need for PCI.

I've written firmware for embedded devices that utilise a PCI buss, they don't always have to have edge connectors on backplane, the specification can be used internally as well.
But again, you're way off topic ;)

I've written firmware for embedded devices that utilise a PCI buss, they don't always have to have edge connectors on backplane, the specification can be used internally as well.

Interesting. What is the purpose of using PCI with no edge connectors?