I've had several different explanations as to why one is better than another... none of them make a whole lot of sense.

What's the deal?

Balanced versus unbalanced.

A balanced cable will have three conductors; plus, minus, and ground. It typically uses an xlr connection. It is well shielded, and is used in pro situations because of that.

Unbalanced typically uses an rca style connection, which has two conductors. The plus is the center conductor, and the minus is the shield. Better quality cables will have three conductors, but will lift the third bare conductor at one end, effectively cutting the transmission of noise.

I would add that a balanced cable, in theory is always going to be better.

Here is the classic Rane Corporation document on balanced audio applications for the pro world. There is a lot of other useful stuff on their site.

Also the balanced audio feeds are significantly hotter, like 6dB or more, than the single ended (RCA) connections. A stronger signal would maintain a lower noise floor even if it didn't have the advantage of balanaced topology. Since it has both going for it, a balanced cable can be noise free for Loooooong runs.

LOL, I know what they are and how they look and all that. (Thanks Fred)

Maybe I should be more clear... Pro's-Con's?

We just got in some new Classe Audio gear and it has both. Why should I set up the DVD player with a balanced Digital feed and the connection between the Processor and amps? They are all within a the same rack.

I'll go look at that link in a few ;-).

Andy

As far as the analog connections between the preamp/processor and the amps, the benefit will be a lower noise floor... better dynamic range, more detail, etc.

This is because of the rejection from the balanced design as well as the higher signal levels.

As for the AES/EBU digital... more of the 1's and 0's get where they are going in the same order that they left (lower jitter) compared to the S/PDIF digital connection standard.

Again, because of the low noise floor due to the design and signal level.

The one on "Grounding and Shielding Audio Devices" should be also be required reading. Worth reading just for the great drawing of a guy trying to avoid getting pokey electrical things in his crotchel area as he jumps the balanced/unbalanced fence.

Rane goes after the whole "What do I do with Pin 1" question & talks about mixing commercial/balanced and consumer/unbalanced.

This whole subject *should* be simple but it's not cut & dried at all.

Everybody say "Thank you Rane!"

Because they've enabled you to do so.

At that point, spending a few extra bucks on a balanced cable should be a moot point. Aside from cost, I can think of no reason to use unbalanced when you have balanced as an option.

And because of the very low noise floor and the noise immunity gotten from the pair being twisted (one of the oldest applications of twisted pairing in this industry), it is used for microphone signals where the level is around -60 dBm. I once recorded a gospel music workshop where we had clear miking without any kind of preamps and a few of the cables were almost 200 feet long!

Anyone want to start the transformer vs electronic balancing argument?!?!

Here is a quick breakdown on balanced. There are 3 conductors. One is ground. The other 2 are hot and both carrying the audio signal, but one is exactly out of phase with the other. Any noise picked up by the wire will be equal on both conductors. When the audio reaches the recieving device, the out-of-phase audio on the 2 wires is flipped back in-phase and combined together, causing any noise picked up along the way to now be out-of-phase. This causes the noise to be cancelled out.

This message was edited by follow who03 on 11/15/05 11:23 ET.

The Rane link that was provided by avophiliac is one of the best tips I've seen in awhile.

Thanks!

Mike

My vote goes for transformer but, as with all things, it comes down to proper implementation. Generally if you see a piece of pro gear with a ground lift switch, you can figure it wasn't implemented properly.

2nd Rick is defintely right about the signal being a higher level in a balanced connection it is actually 14db+ because balanced signal runs @ +4db as unbalanced is -10db.

This message was edited by LiveWire on 11/16/05 10:09 ET.