or Connect
Head-Fi.org › Forums › Help and Getting Started › Introductions, Help and Recommendations › I need help getting my head around balanced in/out.
New Posts  All Forums:Forum Nav:

I need help getting my head around balanced in/out.

post #1 of 11
Thread Starter 

Okay... From what I understand by reading through the Net, a balanced signal is something like active noise cancellation headphones (not exactly the same, but the inverse/regular signal thing seems to be that way to me). 
 

External Noise cancellation:

 

So you've got a hot signal being the regular one and a cold signal being the inverse one. When it reaches a signal processor, should you have noise present in the signal, they get cancelled out. I don't understand this part as to why and how it gets cancelled out. Wikipedia helped to solve this.

Mono or stereo:


Also, from logic, and experience with wiring TRS connectors, it does not make sense to me as to how one can have stereo with one XLR jack. If there are two shared inputs and one ground, isn't that mono? Does it mean that for stereo, one needs two jacks and two cables, or is there some black magic going on in the signal transmitter?

 

The point of using this in IEMs:

 

I've seen people using IRIS connectors (through balanced output by the amp) directly connected to their IEMs. What happens is that they jack the connectors to their amps (Ray Samuel's amps or the Cypher Labs Theorem) and play through. What I don't understand is if the signals require processing, then how is it that IEMs can process the sound? Unless the signals have been pre-processed and the IRIS connector is just another connector like the TRS 3.5mm jacks found in phones, but rewired?

 

Thanks in advance.


Edited by AONihilist - 3/17/14 at 10:55pm
post #2 of 11
Quote:
Originally Posted by AONihilist View Post
 

Mono or stereo:


Also, from logic, and experience with wiring TRS connectors, it does not make sense to me as to how one can have stereo with one XLR jack. If there is two shared inputs and one ground, isn't that mono? Does it mean that for stereo, one needs two jacks and two cables, or is there some black magic going on in the signal transmitter?

 

 

Mono is the same positive and negative signal split into two different drivers, whether it was recorded in mono playing through stereo or actual hardware wired in mono. If you have two different positive signals, they can share a ground and still remain stereo. In some amps there is an active ground circuit, effectively making it three channel in terms of positive and negative circuits, whereas a balanced amplifier will use four channels - one each positive and negative on each channel.

 

TRS plugs have both mono and stereo versions, the latter having two black strips across the plug. A guitar will use the mono version while a headphone uses the stereo.

 

Quote:
Originally Posted by AONihilist View Post

 

The point of using this in IEMs:

 

I've seen people using IRIS connectors (through balanced output by the amp) directly connected to their IEMs. What happens is that they jack the connectors to their amps (Ray Samuel's amps or the Cypher Labs Theorem) and play through. What I don't understand is if the signals require processing, then how is it that IEMs can process the sound? Unless the signals have been pre-processed and the IRIS connector is just another connector like the TRS 3.5mm jacks found in phones, but rewired?

 

I am not sure what you mean about "pre-processed signals" but on the headphone end, some cables have only four conductors from the drivers to the Y-junction, and from there the two grounds are soldered into a common ground cable and only three from there to the TRS plug; on larger headphones you can have three cables running from the left cup, and internally, the right cup is wired to that terminal also.

 

However some have four conductors all the way through to the TRS plug, in which case you can just chop this off and solder on a 4-conductor TRS or other such 4conductor+ balanced plug, like a IRIS or the 6-conductor Hirose. Note that a single-ended amp design can power IEMs or headphones adequately and having balanced output is not the same as a fully-balanced amp, the latter taking up more space due to four discrete circuits. A balanced output amp for the most part likely has more power for the same footprint and this is what you might find in a portable balanced amp, and personally close to 1wpc on IEMs is a bit of an overkill.


Edited by ProtegeManiac - 3/17/14 at 11:03pm
post #3 of 11
Thread Starter 
Quote:
Originally Posted by ProtegeManiac View Post
 

 

Mono is the same positive and negative signal split into two different drivers, whether it was recorded in mono playing through stereo or actual hardware wired in mono. If you have two different positive signals, they can share a ground and still remain stereo. In some amps there is an active ground circuit, effectively making it three channel in terms of positive and negative circuits, whereas a balanced amplifier will use four channels - one each positive and negative on each channel.

 

TRS plugs have both mono and stereo versions, the latter having two black strips across the plug. A guitar will use the mono version while a headphone uses the stereo.

Okay... Maybe I said it a little wrongly. Won't it be single-channel instead of dual-channel? Meaning I only get one side instead of both.

 

 

Quote:
Originally Posted by ProtegeManiac View Post
 

 

I am not sure what you mean about "pre-processed signals" but on the headphone end, some cables have only four conductors from the drivers to the Y-junction, and from there the two grounds are soldered into a common ground cable and only three from there to the TRS plug; on larger headphones you can have three cables running from the left cup, and internally, the right cup is wired to that terminal also.

 

However some have four conductors all the way through to the TRS plug, in which case you can just chop this off and solder on a 4-conductor TRS or other such 4conductor+ balanced plug, like a IRIS or the 6-conductor Hirose. Note that a single-ended amp design can power IEMs or headphones adequately and having balanced output is not the same as a fully-balanced amp, the latter taking up more space due to four discrete circuits. A balanced output amp for the most part likely has more power for the same footprint and this is what you might find in a portable balanced amp, and personally close to 1wpc on IEMs is a bit of an overkill.

What I was asking was more like "how do they get their IEMs to play balanced input?" I mean, from what I can see, they made upgrade cables terminated with the IRIS connector and plug it into their amps one end and their CIEMs the other.

post #4 of 11
Quote:
Originally Posted by AONihilist View Post
 

Okay... Maybe I said it a little wrongly. Won't it be single-channel instead of dual-channel? Meaning I only get one side instead of both.

 

How is that possible when you have two positive conductors, left and right, each playing...well...left and right channel? Put on any IEM, headphone, or whatever you have, go to YouTube, then search for "stereo test." If it's wired in mono you'll hear everything in the center, and it won't move to the left nor right.

 

Quote:

Originally Posted by AONihilist View Post
 

What I was asking was more like "how do they get their IEMs to play balanced input?" I mean, from what I can see, they made upgrade cables terminated with the IRIS connector and plug it into their amps one end and their CIEMs the other.

 

Well two conductors carry the left positive and negative signal, then two conductors carry the right positive and negative signal. Like I said, in some cases some IEM or headphone cables can be four conductors all the way through, like the stock cable on the HD600/650/580, which is why you can get an otherwise stock cable reterminated with a Hirose plug straight from Ibasso. On IEMs, again like I posted above, some can have only three wires coming from the Y-junction to the TRS plug, so in those cases they redo the entire cable. Your "upgrade" balanced cable comes with four wires braided as one, then splits into two braided pairs after the Y-junction going to the shells, so in effect you have four conductors all the way through - two for the left channel's positive and negative, and two for the right channel's positive and negative.

post #5 of 11
Thread Starter 
Quote:
Originally Posted by ProtegeManiac View Post
 

 

How is that possible when you have two positive conductors, left and right, each playing...well...left and right channel? Put on any IEM, headphone, or whatever you have, go to YouTube, then search for "stereo test." If it's wired in mono you'll hear everything in the center, and it won't move to the left nor right.

 

What I meant was: In an XLR jack, there are three pins, positive (hot), inverse (cold) and ground, correct? If so, then seeing that hot and cold are both inputs (input+ and input-), then isn't that only one channel input? 

 

 

 

As for your second point, I understand how an IEM/headphone works. For each side, there is a positive and a negative (i.e. ground). So in total there are four wires in each cable. I know that.

What I do not understand is, if a balanced signal is only a hot and cold signal, a regular and an inverse signal, how does an IEM cancel the sound when there isn't a signal processor inside it? 

 

Maybe you could link me to somewhere that explains balanced output in a easier-to-understand way in specifically done for audio?


Edited by AONihilist - 3/17/14 at 11:41pm
post #6 of 11
Quote:
Originally Posted by AONihilist View Post
 

 

What I meant was: In an XLR jack, there are three pins, positive (hot), inverse (cold) and ground, correct? If so, then seeing that hot and cold are both inputs (input+ and input-), then isn't that only one channel input? 

 

Sure that's one channel, but then again, that's why there are two XLR jacks in the back. If it has only one XLR jack in the front, it's a four-conductor XLR jack - there is such a thing, the same way there's a four-conductor TRS jack usually used for headsets but is now being used for balanced headphones to use a more compact jack, like on the HiFiMan HM700 balanced output portable audio player. Also, just because an input requires six conductors does not mean that on the headphone/speaker end there should also be three. Balanced connection speaker amps also still have just four on the speaker outputs.

 

If you see a single XLR jack labelled as an input and no other jack paired with it, it's a digital input - very likely for there to be a single RCA port next to it too.

 

 

Quote:
Originally Posted by AONihilist View Post

 

 

As for your second point, I understand how an IEM/headphone works. For each side, there is a positive and a negative (i.e. ground). So in total there are four wires in each cable. I know that.

What I do not understand is, if a balanced signal is only a hot and cold signal, a regular and an inverse signal, how does an IEM cancel the sound when there isn't a signal processor inside it? 

 

Maybe you could link me to somewhere that explains balanced output in a easier-to-understand way in specifically done for audio?

 

http://www.youtube.com/watch?v=jo5HhfIUSP0

post #7 of 11
Thread Starter 

Thanks. That clears things up quite a bit.

Anyway, does anyone happen to know how to wire an upgrade cable for CIEMs? I remember seeing someone doing that, but I didn't ask him and I haven't seen him since.

What I saw was simply the IRIS connector (Ray Samuel's SR-71B) wired up to an upgrade cable which jacked into a CIEM. Westone/CIEM regular dual pin, FYI.

I did the same, following the wiring at Ray Samuel's website, but when I tried it on both ALO and Cypher Labs' amps, I get a very distorted sound. It reminds me of a wiring fault that I had a long time ago, but I cannot remember what the fault was.

Is there something that must be added?

post #8 of 11
Quote:
Originally Posted by AONihilist View Post
 

Anyway, does anyone happen to know how to wire an upgrade cable for CIEMs? I remember seeing someone doing that, but I didn't ask him and I haven't seen him since.

What I saw was simply the IRIS connector (Ray Samuel's SR-71B) wired up to an upgrade cable which jacked into a CIEM. Westone/CIEM regular dual pin, FYI.

I did the same, following the wiring at Ray Samuel's website, but when I tried it on both ALO and Cypher Labs' amps, I get a very distorted sound. It reminds me of a wiring fault that I had a long time ago, but I cannot remember what the fault was.

Is there something that must be added?

 

Check your soldering job, there might be something in there that's touching another solder point. Just to be clear, that's a dual pin on each IEM but all four conductors go through all the way to the plug, right?

post #9 of 11
Thread Starter 
Quote:
Originally Posted by ProtegeManiac View Post
 

 

Check your soldering job, there might be something in there that's touching another solder point. Just to be clear, that's a dual pin on each IEM but all four conductors go through all the way to the plug, right?

Exactly. What I'm thinking the issue is is that the pinout diagram I used was wrong, resulting in my L+ using my R- and vice versa. Not entirely sure though, and it's pretty hard to find a proper pinout diagram for the IRIS/RSA connector specifically done for audio.

post #10 of 11
Quote:
Originally Posted by AONihilist View Post
 

Exactly. What I'm thinking the issue is is that the pinout diagram I used was wrong, resulting in my L+ using my R- and vice versa. Not entirely sure though, and it's pretty hard to find a proper pinout diagram for the IRIS/RSA connector specifically done for audio.

 

That's also possible. Did you email your amp manufacturer to check what their pin assignments are?

post #11 of 11
Thread Starter 
Quote:
Originally Posted by ProtegeManiac View Post
 

 

That's also possible. Did you email your amp manufacturer to check what their pin assignments are?

I've checked around the web and it turns out that Ray Samuel's, Cypher Labs and ALO all use the same configuration. It must be my pinout diagram. I've fixed it, and I'll try it out again later. A little busy ATM.

New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Help and Getting Started › Introductions, Help and Recommendations › I need help getting my head around balanced in/out.