Uni Directional Subwoofer Cables - Page 3

Trust me on this. I do read and understand schematics rather well. I make a nice living drawing them, using them, and building rather extensive AV systems for many years.

As I said earlier, the picture shown with a single ended cable connection (RCA) is of absolutely zero difference electrically from a straight through soldered connection shield to shield tie point on the connectors. There is zero benefit OR electrical change in the IC circuit between 2 devices so connected. NONE.

Anyone who touts that has very little experience in the real world of audio interconnects. The ONLY benefit to lifting one end of a shielded pair is IF and ONLY if the devices are using balanced input/output connections where neither the phase nor the return is referenced to ground AND there is a low voltage potential difference between the chassis or signal grounds of the aforementioned units.

This can occur if they are powered by different AC phases, opposite legs of the same phase (as in a home system) or are separated by a distance such that there MAY be a higher resistance to earth ground of one unit from the other.

We see this frequently in commercial / professional installs where the amp racks are not adjacent to the mix desk/ source rack.

Single ended RCA to RCA is electrically the same no matter what you do to the cable. As long as there is a shielded connection and phase, the cable functions identically to an off the shelf RCA cable.

In actuality and in practice, if you are in a noisy environment interference wise, using the wiring scheme shown with no shield connection right at both connectors may well impede the clean audio and allow a substantial hum in the system.

I disagree. Depending on the circumstance,the method of wiring you say can't make a difference-sometimes can.

Take a guitar for example. It is an unbalanced cable going to the amp.

By using a twisted pair to carry the actual signal and the shield hooked up only at the amp end (assuming the amp is properly grounded) can sometimes help reduce the hum that in induced into the wire.

Since the shield is not carrying any signal (as it does in a regular coax cable) it can effectively help shunt the interferenced to ground (through the amp), and not get onto the signal path-at least as much anyway.

But as in all things, it depends. I have seen it work well and in other cases-not do much at all in reducing the noise. It depends on the noise itself, how well the amp is grounded, the internal wiring of the amp and the particular guitar.

Electrically it doesn't matter-the signal will pass either way-but noise can be a weird animal to tame.

Again - grounded to what exactly? Remember, we are talking about RCA connectors here.

The shield is still connected via the second wire of the TP. The TP conductors go straight from point A to point B. Therefore the circuit is identical.

I have about 40+ years doing this in every venue type and size you can imagine including theaters, recital halls, convention centers, hotel ballrooms conference rooms with satt trucks, recording trucks, genny power, dirty facility power, permanent amp racks, portable amp racks, building to building hard wire feeds, microwave linked feeds, and telco feeds so I am rather experienced in noise, hum, power issues with regards to audio and video.

Good idea.

Concerning the twisted pair you're referring to using in your guitar cable, are both of the conductors connected to the tip of the TS connector, or is one on the tip and one on the sleeve?

If both conductors of the twisted pair are on the tip and the now broken shield was on the sleeve, you have broken the signal path. Good luck getting it to work.

If one conductor of the twisted pair is on the tip and one is on the sleeve, then it makes no difference whether or not you have a shield that is connected to only one end. The shield does nothing because you have another conductor going from one sleeve to the other.

If I misunderstood you completely, I apologize. But your post makes no sense to me.

Though there seems to be confusion in this thread because some are discussing balanced and some are discussing unbalanced (and I think some don't know the difference), I agree with Gizmologist on all fronts.

Ok, i think i get it now. But, is that still called "grounded"?


Yeah yeah, your internet penis is bigger than mine

the ground path is complete if you connect a shield OR one side of a TP from chassis to chassis connections.

As to your cyber biology, I am not touching that. No pun intended.

I actually started in this biz with my dad in '64 on the weekends and by '69 I was working part time. Graduated in '71 and went right to work in this biz.

Is neutral connected on both sides?

otherwise you have no circuit.
In audio the "neutral" is actually referred to as the return.

Of course.

I asked that before reading post #64 and 66.

No Balanced interlinks can be terminated in A few different configurations & also depending on the pin layout required by the Components..

True Balanced consists of 3/4 conductors, the most common is
Hot(red) pin 2
Return (black) pin 3
Shield pin 1

If you go back and take A look at the PDF I posted you will see the Teminations of Balanced interlinks..

Cheers..

" A balanced RCA cable comprises of a twisted pair with one wire connecting to the hot pin. The other wire and the outer shield (ground) connects to the RCA body."

This is an oxymoron. In no way, no how, nowhere can an RCA equipped cable be considered balanced.

Please Google the term "balanced audio" since my explanation does not seem to to have registered.

A True Balanced cable, XLR or TRS is nothing like Unbalanced/single ended RCA
interconnects, RCA is not A analog Balanced interlink connection..

Given the Choice Balanced is usually the prefered method and is
pretty much exclusively used in the Pro Audio industry, and some High End Audio gear..

Cheers..

A bit of patience needs to be in reserve during online communication due to its inherent inefficiencies. Some will exploit that inefficiency to sell snake oil since it's easier for them to disguise their BS. The best antidote to that is to be informed and this is one of the better forums for it.

If you felt insulted by the term oxymoron, please understand that is NOT an attack against you or anyone else.

I apologize if you took it that way.

When I said "oxymoron" it means only that the terms RCA and balanced are mutually exclusive.

A left ch and right ch signal pair is NOT a balanced signal. You need to ignore most of the audiophile cable sites for info. SOME are accurate and scientific but most are reptilian saturated fat rendering. (snake oil) and NOT based on actual audio technology that is industry accepted.

A balanced cable will have 1TP carrying the same signal but out of phase. The signal path is basically a complete loop from one device output to another. The shield is strictly for hum blocking, noise elimination and is not part of the signal path.

On an RCA (single ended, Hi-Z and unbalanced are additional terms for the same thing) The center pin is hot on both ends and the shield IS part of the signal path. no matter how someone uses a TP wire and uses it to connect it to an RCA connector it is, by definition, an unbalanced cable.

In a truly balanced interconnection, the shield can frequently be disconnected on one end completely as the audio path is not on or part of the shield. Disconnecting the shield on either end of an RCA type cable will result in extreme hum, noise and distortion of the signal.

I hope this clears it it up for you.

Not that I think it will matter much, but why can't you lift the shield on one end of an RCA connection where the shield is not needed to complete the signal path, i.e. where there is a twisted pair, one being hot and the other the ground return. The shield could then be connected at both ends, one end, or neither, and the circuit path will be uninterrupted. The shield need not be part of the circuit path as you insist. In fact, since there exist non-shielded RCA cables, it is a logical impossibility that the shield always be part of the circuit path.

Semantics, I'm sure, but it probably is confusing a lot of people here.

And for the record, I am a firm objectivist, have been for years, and think that the vast majority of cables sound exactly alike (this applies to analog, digital, speaker, power, whatever). Where there is a difference, it is because one cable was not designed and/or sized properly for the job.

Twisting 2 wires, one hot and the other ground will provide shielding thus it still is a shielded cable whether the outer shield braiding is connected or not.

ELECTRICALLY yes there is a complete path if you use both conductors of a TP- one to shield and one to the tip. HOWEVER as the signal path is a hi impedance circuit, you will have a hum laden and probably microphonic cable and it will make a great radio antenna.

Shielded cabling carries data (on pro grade cables) of the percentage of shielding as it varies from style to style. For instance spiral wrapped shielding (the cheapest and easiest to produce) carries an avg max effectiveness of 75% on a good quality cable. Braided shielding is much better as it is usually around 95-98%. Z wrapped foil shielding is usually rated at 100%.

In short, there MUST be a return path from source to amp through the IC cable. This requires 2 conductors. Using the "telescoping shield" (a non existent term for describing cabling outside of the audiophile world)diagram does not do anything that a standard RCA off the shelf cable would not.

It is NOT balancing a line. There are no paired conductors NOT connected to ground reference as in a truly balanced pair and there is zero benefit to spending the time or money to build one.

For those who want to believe it does, please explain from a technical aspect from your own knowledge WHY it should make a difference. Using a sales brochure or quoting someone else trying to sell them does not count.

Guys you have to remember that there are proven and repeatable laws of physics that a salesman or cable hawker cannot alter. The experience of hundreds of thousands of engineers, sound system installers and designers for the past 80 years have proven the efficacy and the functionality of the concept of balanced vs unbalanced and exactly WHAT the definitions are.

Even if there was a such thing as a "directional" cable I wouldn't want it, I don't like things that can only be inserted one way.


Maybe they are for people who don't know how to properly insert the plug


Thats funny

This is a concise and accurate statement. Balanced can be connected to unbalanced but I believe in doing so the line becomes effectively unbalanced. RCA to TRS or XLR. To maintain a balanced signal some kind of interface needs to be used to match voltage levels. There are several methods to do this to go from balanced to unbalanced and vice versa but I would suspect it is generally better to stick with balanced throughout and not try to combine the two.

"This is a concise and accurate statement. Balanced can be connected to unbalanced but I believe in doing so the line becomes effectively unbalanced. RCA to TRS or XLR. To maintain a balanced signal some kind of interface needs to be used to match voltage levels. There are several methods to do this to go from balanced to unbalanced and vice versa but I would suspect it is generally better to stick with balanced throughout and not try to combine the two."

Going from 2-3 conductors or balanced to unbalanced does in fact unbalance the whole interconnect AND it carries additional burden of impedance and most probably level mismatching as unbalanced signals are substantially lower (-10db) than most balanced signals (+4>+18). Depending on the circuit design, there may well be a dramatic lessening of true fidelity as well.

I have had folks not understand the word before and get offended.

Is part of the problem, there are or were 3 RCA connectors?

1) RCA Phono (note the last O)
2) RCA 1/4in. Mono Phone (note the last E) or TS
3) RCA 1/4in. Stereo Phone (note the last E) or TRS

The SIGNAL travels on the twisted pair-one wire to the tip and the other wire to the ground/sleeve or whatever you want to call it.

The shield is NOT used to carry the signal, but rather as a true shield in which any noise that gets "onto" the shield will then be directed to ground (assuming the piece of gear that the has the end of the shield hooked up has a good path to ground. Not all do.

It is not about completing a circuit, but rather dealing with the noise that gets onto the cable.

"The shield is NOT used to carry the signal, but rather as a true shield in which any noise that gets "onto" the shield will then be directed to ground (assuming the piece of gear that the has the end of the shield hooked up has a good path to ground. Not all do."

Please show me ANY unbalanced audio INPUT to an amp that does NOT need a shield. As explained at least 3 times. it makes no difference whether you use 1 wire in a twisted pair as the return (and ALL audio circuits need a return of some sort) connected to the sleeve or ground (shield) connection or you use the correct method and use the actual shield. If at ANY point in the interconnect between A and B you use some sort of a conductor connected between the grounds you have a ground between the circuits
Leaving one end of the shield on an UNBALANCED cable does nothing electrically. You can use an unshielded TP for a very short distance in some cases (a couple feet max) before you begin to present the amplifier with extraneous noise /hum. This is WHY we use shielded cables.

Doing that on a truly BALANCED setup is a whole other scenario.