Topic: pin 2 hot, pin 3 hot.... ahhhh!

[atxwolfattack]

Okay, i am going to be recording a show in 2 weeks where i will mic the show, and get a soundboard recording on my other iRiver. I have read pretty much all the soundboard posts, and have all the correct adapters, but i seriously have no idea what this pin 2 hot, pin 3 hot stuff is. Is the point to avoid the hot inputs if they are labeled on the board, or are those the ones you want to patch from. I know i probably sound dumb asking this, but i really couldn't find my answer anywhere.

thanks guys,

Josh

[Church-Audio]

Okay, i am going to be recording a show in 2 weeks where i will mic the show, and get a soundboard recording on my other iRiver. I have read pretty much all the soundboard posts, and have all the correct adapters, but i seriously have no idea what this pin 2 hot, pin 3 hot stuff is. Is the point to avoid the hot inputs if they are labeled on the board, or are those the ones you want to patch from. I know i probably sound dumb asking this, but i really couldn't find my answer anywhere.

thanks guys,

Josh

There is absolutely no standard for outputs on consoles they can be pin 2 or pin 3 hot. However for mic inputs the standard is pin 2 hot. So if your taking an output from a console and you can take a 1/4 inch unbalanced output and connect it to your recorders unbalanced input you will be fine.

This pin 2 pin 3 stuff refers to a mixers balanced inputs or output polarity.. Balanced outputs on a console are 180 degrees out from one another so for example if pin 2 was hot on a mixers output you would say that pin 3 is 180 degrees out from pin 2. Pin 2 in this case would be producing a positive signal and pin 3 is an inverted signal that is 180 degrees out from pin2 this is how balanced signals create the high rejection ratio of noise. By introducing a pair of signals that are 180 from each other you can phase cancel inducted noise and interference leaving you with a crystal clear signal ( in theory ) I know this was not the best explanation of this but, as long as you try when ever possible to take a "unbalanced" output from the console you are getting your feed from you will be fine. Some consoles do not have "unbalanced" outputs. In this case just ask the sound engineer what pin on this console is hot for the output. They might look at you strange but they will respect your knowledge, some sound guys think its not important lol they are wrong.. When you combine systems together that are balanced you MUST maintain the correct polarity on the inputs and outputs of each system in the chain.
You can build simple cables that "swap" pin 3 and 2 have one marked pin 2 hot one marked pin 3 hot the other end of the cable will be wired correctly for your input then you can be sure to be ready for any situation that might come up. Sometimes the sound engineer will not know what pin is what.. It might be writen on the back of the console.. mag light to the rescue.

Chris

[Nick's Picks]

well said.

some more info w/pictures.  this is just various cable info, but useful.
http://en.wikipedia.org/wiki/Jack_plug

[atxwolfattack]

okay, so you are saying for your example, that if i am using a 1/4 unbalanced output ( so is 1/4, and rca always unbalanced?) and pin 2 is hot on the console, then i would want to plug into a pin 3 output, because 2 unbalanced signals kind of cancel each other to make a good signal. Am i correct about that?

So then my next question is, I have a mini to rca cable, and then adapters for 1/4, and xlr, is there any way of knowing if my cable and adapters are balanced or unbalanced?

Just to make sure i have this right, for the most part, if you have a balanced signal coming into the console, and pin 2 is hot, then you want to plug into pin 2 because they are both positive signals, correct? But if you have an unbalanced signal coming into the console, and pin 2 is hot, you want to plug into pin 3, because it is the inverted signal, and they will phase cancel each other and have a good signal?

thanks.

Okay, i am going to be recording a show in 2 weeks where i will mic the show, and get a soundboard recording on my other iRiver. I have read pretty much all the soundboard posts, and have all the correct adapters, but i seriously have no idea what this pin 2 hot, pin 3 hot stuff is. Is the point to avoid the hot inputs if they are labeled on the board, or are those the ones you want to patch from. I know i probably sound dumb asking this, but i really couldn't find my answer anywhere.

thanks guys,

Josh

There is absolutely no standard for outputs on consoles they can be pin 2 or pin 3 hot. However for mic inputs the standard is pin 2 hot. So if your taking an output from a console and you can take a 1/4 inch unbalanced output and connect it to your recorders unbalanced input you will be fine.

This pin 2 pin 3 stuff refers to a mixers balanced inputs or output polarity.. Balanced outputs on a console are 180 degrees out from one another so for example if pin 2 was hot on a mixers output you would say that pin 3 is 180 degrees out from pin 2. Pin 2 in this case would be producing a positive signal and pin 3 is an inverted signal that is 180 degrees out from pin2 this is how balanced signals create the high rejection ratio of noise. By introducing a pair of signals that are 180 from each other you can phase cancel inducted noise and interference leaving you with a crystal clear signal ( in theory ) I know this was not the best explanation of this but, as long as you try when ever possible to take a "unbalanced" output from the console you are getting your feed from you will be fine. Some consoles do not have "unbalanced" outputs. In this case just ask the sound engineer what pin on this console is hot for the output. They might look at you strange but they will respect your knowledge, some sound guys think its not important lol they are wrong.. When you combine systems together that are balanced you MUST maintain the correct polarity on the inputs and outputs of each system in the chain.
You can build simple cables that "swap" pin 3 and 2 have one marked pin 2 hot one marked pin 3 hot the other end of the cable will be wired correctly for your input then you can be sure to be ready for any situation that might come up. Sometimes the sound engineer will not know what pin is what.. It might be writen on the back of the console.. mag light to the rescue.

Chris

[Church-Audio]

okay, so you are saying for your example, that if i am using a 1/4 unbalanced output ( so is 1/4, and rca always unbalanced?) and pin 2 is hot on the console, then i would want to plug into a pin 3 output, because 2 unbalanced signals kind of cancel each other to make a good signal. Am i correct about that?

CHRIS
1/4 is not always unbalanced but for the most part even if you plug a mono jack into a ring tip sleeve 1/4 jack you will get an unbalanced signal. The tip on a ring tip sleeve will always be positive. The exception to this rule is QSC amplifiers they use the ring??? as positive lol and the tip as negative. RCA is ALWAYS unbalanced with the center hole being positive.

So then my next question is, I have a mini to rca cable, and then adapters for 1/4, and xlr, is there any way of knowing if my cable and adapters are balanced or unbalanced?

CHRIS

The RCA to 1/4 has to be unbalanced.. If one side of the cable is a two conductor plug the signal is then a unbalanced signal, the exception is twisted pair with no shield, but you will never ever run into that in an audio console.

Just to make sure i have this right, for the most part, if you have a balanced signal coming into the console, and pin 2 is hot, then you want to plug into pin 2 because they are both positive signals, correct? But if you have an unbalanced signal coming into the console, and pin 2 is hot, you want to plug into pin 3, because it is the inverted signal, and they will phase cancel each other and have a good signal?

thanks.

CHRIS

If you have an unbalanced signal from the console chances are its not via an XLR connector.. It will be 1/4 or RCA... if you have a XLR connector you must assume its balanced.. They are more expensive and companies do not put them on unless they have to, so it will be a balanced output. If pin 2 is hot on your recorder, you must make sure that you find out what pin is hot on your console. If its pin 3 you must use what is called a phase reverse adaptor that swaps pin 2 for 3 on one end only. If your recorders inputs are "unbalanced" you must make a cable that has the proper connector for your recorder on one end and the "unused" pin on the console * the pin that is 180 degrees from the positive must be tied to pin 1 ground. So if you have a console that has a pin 2 hot output you must tie pin 3 to ground and then connect pin 2 to your recorders positive input connector and pin 1/3 must be tied to the ground on your recorders input. What you have now done is you have made the consoles output unbalanced by making the connection the way I described it. So why tie the unused pin to ground? Because even though its an output the unused pin should be tied to ground to minimize the chances of inducted noise into the console it self.


I know in a way this is a complicated topic but once you wrap your head around the basics you will be more confident of the connections you need to make, and come off as much more professional to the sound engineers your dealing with. We like that.. Knowledge is power. A lot of people think its just a matter of setting up a few mics and calling it a day.. And for some thats ok. But for me its always been the drive to learn more. I learn something every day about audio and no one knows everything. So keep asking questions keep learning because the more you know the better your recordings will be and never just take my word for it.. The Internet is a beautiful thing.. I wish I had the Internet when I was starting out in audio.. I had to buy "books" lol..


Chris

[atxwolfattack]

crap, i am even more confused now. How about this, lets just say i plug into the wrong one. Like say i have an unbalanced signal, and i plug into pin 2 hot (positive), what will happen?

thanks

[Church-Audio]

crap, i am even more confused now. How about this, lets just say i plug into the wrong one. Like say i have an unbalanced signal, and i plug into pin 2 hot (positive), what will happen?

thanks

LOL dont be!

Lets say for argument sake you just want to record a feed from a console and you dont have any room mics..

Your recorder has an unbalanced input. So that means 1/4 or stereo 1/8th you then connect the wrong pin from the console to your recorder.. Say pin 2 ( when the console output was actually pin 3 hot) What will happen...

You will get audio that is 180 degrees out of phase from the original source. Is that a big deal?? well some people say that it makes a huge difference on playback because your speakers are not moving in the same direction with reference to the actual performance. Some people say they can hear it.

So lets add a pair of room mics to this equation...

You have a pair of room mics and some sort of mixer to mix the signal from the room mics and "combine" it with the board feed. Now if your board feed is not in phase with your mics you have what is called "phase cancellation" that means your mics vs your source are 180 degrees out from one another.

What will that do? create comb filtering at certain frequencies and generally speaking create a recording that is substandard. From what it would have been if the polarity was correct.

Remember polarity is absolute something is ether positive or negative. Phase is not absolute and changes with frequency shorter wavelengths are less subjected to phase cancellation due to the shortness of length in real space that they need to develop fully ( high frequency ) so you might not notice high frequency phase cancellation as much as low frequency because of the wavelength. So when you have two sources that are combined that both have the same polarity and phase you get a summation of frequencies usually in the low end resulting in a recording that has better bass response.

A tell tail sign of phase cancellation can be a reduced bass response in a recording ( not always the case ) but its a good rule of thumb if you had 4 tracks and they were stereo pairs one set was a pair of mics the other was left and right from the console and you reversed the phase of one pair by 180 degrees and all of a sudden you have better bass response you can bet that something was not correctly wired and one pair was out of phase.

I know its complicated but you asked

Chris

[atxwolfattack]

ohhhh okay, i get it, if the output on the console is unbalanced, then i don't really need to worry about phase issues, it is only when the output on the console is balanced i have to worry about it.

Okay, i think this makes sense now. If the console has Balanced outputs, and pin 3 is hot, then i should plug into pin 3. But if i were to plug into pin 2, then i would get a recorded that has phase reverse issues.

yay, i think i get it!

[Church-Audio]

ohhhh okay, i get it, if the output on the console is unbalanced, then i don't really need to worry about phase issues, it is only when the output on the console is balanced i have to worry about it.

Okay, i think this makes sense now. If the console has Balanced outputs, and pin 3 is hot, then i should plug into pin 3. But if i were to plug into pin 2, then i would get a recorded that has phase reverse issues.

yay, i think i get it!

You got it. If its an unbalanced signal you dont have to bother with polarity because there is only one way to connect it. If its balanced then you have to worry about all that stuff.

[atxwolfattack]

Hey Chris,

Earlier you said...
"The RCA to 1/4 has to be unbalanced.. If one side of the cable is a two conductor plug the signal is then a unbalanced signal."

So technically, if i am using a mini male to rca male cable (mini into my recorder), and then attaching a rca to XLR adapter, will that be unbalanced or balanced?

So are the inputs on iRiver h-120's balanced or unbalanced? I am guessing they are probably unbalanced right?

If they are unbalanced, then that means i will have to make a total separate cable just for xlr right? I don't get what you would do if you want to use xlr and the recorder is unbalanced?




Last thing, I have 2 separate iRiver h-120's, one for mics, one for the board, so technically if i patch the board on the wrong output so it is out of phase, is it possible to fix this in post? If so, what is the easiest way to do so? It might be obvious when i get it on my computer, but i just don't really know what a phase revered recording sounds like.

[atxwolfattack]

hey Chris, did you see my last question by chance?

[Church-Audio]

Hey Chris,

Earlier you said...
"The RCA to 1/4 has to be unbalanced.. If one side of the cable is a two conductor plug the signal is then a unbalanced signal."

So technically, if i am using a mini male to rca male cable (mini into my recorder), and then attaching a rca to XLR adapter, will that be unbalanced or balanced?

So are the inputs on iRiver h-120's balanced or unbalanced? I am guessing they are probably unbalanced right?

If they are unbalanced, then that means i will have to make a total separate cable just for xlr right? I don't get what you would do if you want to use xlr and the recorder is unbalanced?




Last thing, I have 2 separate iRiver h-120's, one for mics, one for the board, so technically if i patch the board on the wrong output so it is out of phase, is it possible to fix this in post? If so, what is the easiest way to do so? It might be obvious when i get it on my computer, but i just don't really know what a phase revered recording sounds like.

A rca to XLR cable must be unbalanced by shorting out the negative pin of the XLR to ground. This must be done in order to unbalance the audio signal. Your 120 is unbalanced. It is possible to correct absolute polarity after the fact yes. I dont know how you do it in every program I use Nuendo there is a phase switch in the console input in that program. Every program is different, this would be a good question in the computer recording section.

If you have to use XLR to go into your 120 you would make a Y cable that has a 3.5 mm jack on one end and a pair of XLR connectors on the other end. So if the output of the mixer was pin 2 hot you would connect the hot to pin 2 and the shield to pin 1-3. If the output of the mixer was pin 3 hot you would connect the hot to pin 3 and the shield to pin 1-2. If your not sure it can be a problem one way to switch this configuration quirky is to make a xlr cable mark it with Yellow tape, that is the standard color for a phase reverse cable. On one side of the xlr to xlr cable you want to "swap" pin 2 for 3. Mark this as a pin 2 hot cable. Now Wire your original XLR Y cable as pin 2 hot.  So when you get to the board and find out its not pin 2 its pin 3 you can put this "phase reverse cable" in line and reverse the polarity with the adaptor cable you made, you will need two phase reverse cables one for each end of your Y cable. 

Signals that are 180 degrees out from one another generally speaking lack bass. But that's not always the case. When in doubt flip the reverse and listen. In the studio we have phase reverse switches on our consoles so we can hit a button and listen with software it can be a bit more of a challenge but once you find out how to do it you will be able to check by listening for your self.

Chris

[Brian Skalinder]

if i patch the board on the wrong output so it is out of phase, is it possible to fix this in post? If so, what is the easiest way to do so? It might be obvious when i get it on my computer, but i just don't really know what a phase revered recording sounds like.

Very easy to do in post.  Every audio editing program I've used (~4-5 or so on Windows) provides this feature.  I wouldn't sweat the phase reversal cables too much, unless you plan on mixing the SBD on-the-fly with a pair of mics, in which case it might be an issue.

A fully phase reversed recording - one that maintains relative phase between the L and R channels, i.e. pin 2 = (+) for both L and R channels, or pin 3 = (+) for both left and right channels - sounds no different to most people's ears.  It becomes fairly obvious and audible when the L and R channels are out of phase relative to one another, e.g. pin 2 = (+) for the L channel, pin 3 = (+) for the R channel.  But again, that's also easily fixed in post-production via software, and only really a problem if you're mixing multiple channels on-the-fly.