Ballanced Unballanced what does it mean??

[Lobare]

Hi to not sound like a total noob but what is the main difference between ballanced and unballanced output? Is it unballanced has more DC distortion in the signal or is it more to do with the line level to both channels in stereo?? I've never really had not much to do with this so I was just wondering if a more informed person can help me out??

 

[dmills]

A balanced (actually differential) line has significantly better rejection of external interference when compared to an unbalanced line, but the extra parts in the line recever add a tiny amount of noise of their own.

Generally for most HIFI stuff it is a waste of effort for the most part, for most sound reinforcement stuff it is a massive win, because there sending audio over many tens of meters is commonplace and the extra noise rejection massively outweighs the extra complexity and slight increase in circuit noise, different tools for different jobs.

 

[pooge]

In balanced lines, both signal lines have the same impedance to ground.

 

[Ken Newton]

Here's a short but excellent paper explaining those terms in a manner which a novice can understand.

http://www.jensen-transformers.com/an/an003.pdf

 

[abraxalito]

Hi to not sound like a total noob but what is the main difference between ballanced and unballanced output?

Balanced outputs are of marginal benefit over unbalanced, but balanced inputs offer freedom from common-mode induced noise. This is not just because the interconnect cable is an antenna but because with a balanced input there's a dedicated wire to carry the CM noise currents (pin1 on the XLR). In unbalanced the noise currents flow along the screen connection and hence appear in series with the wanted signal. This effect can be minimized though by paying careful attention to cable geometry, one reason why lap-screened el-cheapo interconnects are best avoided where SQ is on the list of requirements.

 

[Chris Hornbeck]

The term "balanced" should be banned from serious discussion; too many possible similar-but-different meanings. It confuses rather than enlightens.

Outputs can be ground referenced or floating, and if "balanced" and ground referenced can be driven on both polarities or driven on one polarity and the other undriven but of equal source impedance. Inputs can be ground referenced or floating, and can be differential between one polarity and ground, or between two polarities.

Calling something "balanced" is the second most confusing term in audio. I say Bah Humbug! (The most confusing is "dB" - almost everybody gets it wrong sometimes.)

Thanks, I feel better now,
Chris

 

[dmills]

Nope, the most confusing has to be 'Ground', meaning what exactly?

Closely followed by RMS Watts.... Stupid meaningless unit, you can talk sanely about RMS current or voltage, but what exactly does the root of the mean of the square of a wattage mean exactly? Yes I know it gets used for 'long term thermal limited power' or something like that, but really.

Regards, Dan.

 

[Chris Hornbeck]

Nope, the most confusing has to be 'Ground', meaning what exactly?

I stand corrected! The new king of confusion, long may he...

Much thanks,
Chris

 

[AndrewT]

Nope, the most confusing has to be 'Ground', meaning ...............

I agree.
And we have brought it upon ourselves.
We are too lazy to be explicit and resort instead to G, or GND or ..... any of these non explicit names that can mean any of dozens of different functions.

Start talking about Signal Return, or Speaker Return, or .......
Then at least we on Diyaudio can be clear about the worst and most confusing of misused terms.


There is nothing wrong with the term "balanced", nor with "unbalanced".

 

[abraxalito]

Yep good idea Andrew - not forgetting 'positive supply return' and 'negative supply return' which will encourage loop thinking as regards currents

 

[Speedskater]

The Jensen Transformer - Bill Whitlock paper edited and expanded by Rod Elliott .

Balanced Interfaces