Balanced vs. Unbalanced audio

[m.]

One of the most clear, precise and accurate descriptions of a Balanced transfer of signal.

Prepared. or unprepared, Paul you have a great ability to explain concepts in a plain and understandable way, brilliant!

[cbcdesign]

One of those simple but brilliant ideas in electronic engineering that makes so much sense when you see the logic behind it in terms of noise rejection.

[bwithrow]

A balanced input does pay attention to noise. The differential [+ and-] inputs to an op amp invert the noise putting it out of phase with itself thus canceling it and it inverts the - input audio to put in phase with the + input audio. The result is clean audio. Another advantage of balanced audio is it is typically +4 where unbalanced is -10

[douglasRbrown]

LOL @ 2:47 the 14 year old in me started laughing (hand gestures). Thank you For taking the time to make and post the videos Sir.

[SuperEightOneEight]

hi paul...i guess if the cable is one end is 3.5mm jack and the other is XLR to the receiver...it wont do any good...or will it?

[christopherdarling]

Thank you Paul for your explanation and defining what true balance is.

[TBD.]

What a wonderful and beautiful channel you can feel the sincerity and helpful advice.

[kjeldpedersen]

Good question and you explain it so that I finally get it😊
Thanks Paul👍

[machstein]

"The Dingus"

I spit my coffee out. Thanks Paul!

[isettech]

Paul, A couple of additional points from the Pro Sound engineering side of things. RCA is generally high impedance on the receiving equipment, so when there is a poor ground connection which is common in RCA cables, induced noise is not shunted to ground but can produce significant noise. RCA terminations are typically 20K to 47 K ohms. Antique crystal microphones were worse with lower voltage signal and termination of 50 to 200 K ohms, refereed to as high impedance microphones. At high impedance source signals, the capacitance of the cable produced huge loss of high frequency on longer cables, and with some dielectric insulators in some cables, the cables themselves were monophonic, so you could hear cables moving or being stepped on. This was called cable rustle. This is now a thing of the past.

Balanced audio in the pro gear realm, brought with it a low impedance standard often referred to as Low Z. I presume the PS Audio is utilizing the advantages of this impedance. For microphones the mixers and gear generally terminated the microphones into a load of 200 to 600 ohms. This low impedance shunted high impedance leakage into cables to ground as they produced very little induced voltage.
In pro gear the standard signal level for interconnections is much higher than consumer gear. Instead of running signals at -14 to -20 dBu, they call zero VU +4 dBu, so the noise levels picked up may be the same, and taken care of by the balanced signal, the actual signal on the wire is a much higher voltage. The termination for line level is often 20K balanced and 10 K unbalanced. This is lower than most RCA equipment. Most pro gear will clip the signal at over 12 volt peaks as the op amps driving the cable are operated from plus and minus 15 volt supplies.

Paul, do you use levels comparable with pro audio gear? Would it drive a good pair of Mackie SRM-450 speakers for example?

FYI, I service equipment for a living as an engineering technician. I repair as well as setup and operate it.

[oorkruiser]

True balanced means there is no conversion from balanced to single ended throughout the signal chain. This can also include power amps. Signals are symmetrical with respect to ground. Ground currents (resulting in common mode signals) is not part of the signal as with the shield on RCA.

Its quite easy to reduce amplified noise with balanced to below hearing threshold with balanced interfaces, but issues can arrise and distortion introduced with non symmetrical (non indentical/mismatched XLR pin 2 and 3) amplification. Also some differential input stages have mismatched input impedances, skewing the symmetry, thus not all common mode noise will be optimally suppressed.

Balanced path that includes some amplification tends to lower second order distortion due to symmetry, but to reduce 3rd order dustortion is more difficult.

[pcbuildfrance]

Majority of balanced cables even when shielded have GND and shield connected together, even high end ones. So balanced cables are all about differential signal.

[felixalonzo]

I remember owning a Rotel RMB1095. Big beautiful amp that said it was balanced. Found out through Home Theater Magazine that it was Quasi Balanced.

[carlomagno]

Thank you for sharing your knowledge, learning a lot here. I have a question, I have a Focusrite Scarlett Solo and it seems the left output only works if I plug the cable halfway through, I mean, you can hear the sound only if the Tip of the cable touches the negative part of the balanced output of my sound interface. The right output works perfectly with the same cable, so the cable is not the problem; with a TRS cable works well but I think it's because the negative part of the bal output sends the sound through the negative of the cable, I don't understand why it doesn't send the negative also through the TS cable. Hope you can clear my ideas, thank you very much for your help. Greetings from Costa Rica.

[ronniepirtlejr]

Thanks I understand what you're saying it cancel out each other!

[gaborhorvath]

Would ve appreciated a bit more background on why true balance is better and why the cheap solution is not capable enough, what audible difference is the result.

[robarthristov]

Hey, I have a question - is TRS to XLR also balanced? (Like TRS toTRS and XLR to XLR are)? Thanks!

[eric]

Excellent video- your knowledge is super, and your explanation of the technology is easily understood by the layman audiophile. Thanks!

[sammau]

Loving your content. Learning so much more from what my school slacked from in less then 10 minutes! Wow!

[kevinbeckenham]

Excellent explanation on how balance circuit works