First time buyer: confused about digital connections/how it all works.

5.1 analog?
Anyway
Yes HDMI carries sound
Most optical outs on TVs are for the built in tuner, It will not pass sound from other inputs.
Yes you would plug everything in to the receiver, but if your using Digital optical for sound, the video can still be routed directly to the TV.

I think by using the RCA 1 and RCA 2 inputs you mean the Digital Coaxial inputs, correct? If so then that is right. Although HDMI is designed to carry audio I don't think that particular HTiB passes audio via HDMI, so you have to use the other digital inputs.

I'd suggest going further into the plunge and getting an AVR / system that will take the audio from HDMI and have a few HDMI inputs available.

It is the wave of the future, happening right now.

I was under the impression that all quality cables were 75 Ohms. Regardless, a good cable from monoprice.com will set you back about $5 for 12'.

Digital coax or toslink/optical audio are required to pass digital sound in order to get 5.1 channels of audio. If you use the standard red and white rca's then you are won't get discrete sound from the surrounds.

The AVR FAQ has a section on connectors. RCA terminated connectors are used for both analog and digital. They are the same cable design, and have a 75 ohm impedence.

Digital Coax IS RCA terminated. Digital Coax = RCA as opposed to optical. Both RCA terminated digital coax and optical are referred to as S/PDIF, the digital audio standard. This passes 2 channel PCM (digital stereo) or Dolby Digital or DTS. It will not handle the newer high resolution audio from Blu-ray. For that you would usually use HDMI. But some Blu-ray players can decode and output multi-channel analog.

Check out the FAQ for more details.

No. Analog audio cables may not be, and if they're not coaxial in design (some are not), they're not 75ohm. That's fine for analog audio, but for digital coax or video, 75ohm cables are required. You can't damage anything by using cables that aren't 75ohm, but you may have audio dropouts, and you can definitely have video degradation due to the impedance mismatch and reflections in the wire.

As above, not necessarily. Many audio cables are not coaxial(since there is no reason that they need to be), and thus are not 75ohm. They are not appropriate for this use. As long as the cable is 75ohm, then you're good to go.

Cheap bets bets?? The Yellow connectored RCA cables from cheapie A/V cables is supposed to be 75ohm, as it's for video.

That's possible. I have not had problems in the past, but I see what you mean.

Most devices seem to have moved to optical. I have not had to hook up an RCA terminated digital cable in years.

At one point in time I looked into RCA cables, and was led to believe that 75 ohms was the standard impendence. Would you say that it's important (for digital) audio for a cable to not only measure 75 ohms of impedence but to be coaxial (for better shielding) ? There's not a lot of sources out there for scientifically accurate and unbiased explanation of such things.

Actually, any cable that is designed for audio and video with RCA plugs is almost certainly coaxial. There are good reasons why even cheap audio cables need to be coaxial: they help prevent noise from being picked up (the outer shield helps greatly) and the fact that the positive signal is surrounded by the negative signal helps cancel out noise. If these were not coaxial, they would easily pick up noise and, therefore, would not even be good for simple analog audio.

I have hacked apart many of these cables throughout the years and they've always been coax. If you doubt my word, try it (you've probably got some cheap cables lying around that you don't use). If the center conductor is attached to a wire that is surrounded by a shield (which attaches to the outer conductor), it is coaxial.

Even cheap coaxial RCA cables will likely work just fine for coax digital connections (I've done it and never had a problem), though you're probably better off with something a bit better. These are not connections that justify expensive cables. If it's short, probably any will work. As the cable gets longer, it's more important to have a quality cable.

It's an interesting topic, as I have not discussed it to this extent in the past (and sorry to partially hi-jack this thread.)

Thus, I did some reading up on this, where I could find information online. My understanding is this -

* All RCA cables are not created equal; the degree to which RCA cables maintain 75 ohm impedence varies
* For whatever reason, they often don't bother to rate RCA cables by impedence. Instead, they seem to sell a cable they claim is analog or digital oe whatever. They do sell digital specific cables, but some are unreasonably costly. There does not appear to be any sort of certification to demonstrate to a buyer that a "digital" RCA cable performs better for that application; caveat emptor, I guess.
* Shorter cable runs apparently are less sensitive to impedence mismatching

If you need an RCA cable for S/PDIF, I would suggest buying an economical digital cable from a trusted source. Don't feel you have to spend a lot. Monoprice has 3ft, 75 ohm RCA cables for a few bucks.

Generally when I cut apart cheapie A/V cables the Yellow is obviously coax and the red and white are obviously just shielded.

Not all shielded cable is coax you know.

Yes it is important for digital audio to be 75ohm coaxial, that's what's specd basically. The frequencies are high enough that impedance mismatch is a concern (where it isn't for analog audio frequencies). That's why it's also required for video circuits, most all of which use 75ohm terminations.

Now, that doesn't mean that you WILL get problems if you don't get 75ohm coax, but certainly it can cause problem, which are usually jsut audio dropouts. given that 75ohm coax can be bought nearly anywhere(electronics stores, radio shack, hardware stores, anywhere that sells wire), and is extremely cheap, there isn't much of an excuse not to have 75ohm coax.

That's not true at all. And you have no idea what you're talking about. Yes, VIDEO cables will almost certainly be coaxial, specifically 75-ohm coax. However audio cables are often not only not 75ohm, they're often not coax at all. What on earth are solder-on RCA ends for? Certainly not for coax, they're used for twisted pair/2-conductor cabling which is fine for analog audio, and widely used. And it's neither 75ohm nor coax. And they work great too, and in some situations are significantly better than coax in certain noisy environments because twisted pair can better reject certain kinds of induced noise that coax acts like an antenna on. On much higher frequency noise, you're correct that coax is superior.

Here's a whole BUNCH of Belden audio cabling that isn't coaxial at all, and very commonly used professionally:

http://www.belden.com/pdfs/03Belden_...red_Cables.pdf

You might be wondering how, for instance, balanced XLR connections are made in the professional domain with a single cable when a coaxial cable has only two conductors(pin and shield). Well gee, maybe that's because it's not coaxial audio cabling at all...



Obviously not more than a few. Your assertions here are ridiculous. I'm sitting inside a warehouse right now that's full of a variety of kinds of audio cabling, and a lot of it isn't coax at all.

That is correct. And further, some are not anywhere close to 75ohm cable because they're not coax, they're analog AUDIO cables which don't have to be 75ohm for any reason.

The ONLY reason that many analog audio cables *are* 75ohm, is because coax is very cheap, and it works great for the task. So why not just sell a whole bunch of the same stuff? It makes sense from a business perspective. It's easier.


Any professional cable certainly will carry an impedance rating, along with many other specs. Much consumer cabling, unfortunately, does not. You can be sure though, that anything labeled "digital audio" or "video" will be 75ohm coax. Something not labeled as such may not be. If you need 75ohm coax for SPDIF or video, get 75ohm coax or something labeled "video" or "digital audio." You may also find that "digital audio" cables may be significantly more expensive than "video" cables for no good reason whatsoever. A 75ohm cable is a 75ohm cable.


Can be, yes. Particularly with video, if the cable is short enough, gross impedance mismatches won't ghost far enough to cause too much of an issue, but it depends on scanrate/resolution etc.


Exactly. 75ohm cables are dirt cheap. If that's what you need, get it. And as a kicker, they work absolutely marvelously for analog audio too, (with some rare but notable exceptions).

By definition, coaxial cable is a single conductor wire surrounded by an outer conductor, which just so happens to function as a shield (coaxial meaning that the two conductors share the same axis). With the RCA plugs used for analog audio, the center contact is connected to a wire that runs down the center and the outer contact connects to the outer conductor (shield). It is true that not all shielded cable is coax. However, if there are only two contacts on a connector (such as an RCA plug) and one is connected to a shield and the other is connected to a wire that runs inside the shield, it is a coaxial cable.



Actually, I do have some idea what I'm talking about. I'm an electrical engineer and part-time musician (for many years). I have a great deal of experience with and knowledge of analog audio signals. I have never seen a 2-contact audio cable (other than speaker cable) that is not coaxial. Twisted pairs work great for balanced signals, such as professional microphone cables. However, these use 3-contact XLR connectors. I believe we were talking about RCA plugs which, the last time I looked, were 2-conductor. Only an incredibly bad manufacturer would use unshielded lines for unbalanced audio signals.

Here's a link which discusses balanced vs. unbalanced audio circuits:

http://www.bluejeanscable.com/articles/balanced.htm

Here's an excerpt that is germane to the topic at hand:


Let's address a few of the other statements you made:

However audio cables are often not only not 75ohm. Why would you say this in response to my quote when I didn't mention 75 ohms at all?

What on earth are solder-on RCA ends for? Certainly not for coax Well, how would you solder coax to an RCA connector? This statement is ludicrous and doesn't mean anything.

Here's a whole BUNCH of Belden audio cabling that isn't coaxial at all, and very commonly used professionally. Yes, for balanced audio lines, not unbalanced.

You might be wondering how, for instance, balanced XLR connections are made in the professional domain with a single cable when a coaxial cable has only two conductors(pin and shield). Well gee, maybe that's because it's not coaxial audio cabling at all.... Here was how I started my post: Actually, any cable that is designed for audio and video with RCA plugs is almost certainly coaxial. Did you happen to notice I qualified my statement by saying with RCA plugs? How many RCA plugs are used in professional applications or with XLR connectors? Pretty astute comment.

Your assertions here are ridiculous. I'm sitting inside a warehouse right now that's full of a variety of kinds of audio cabling, and a lot of it isn't coax at all. Once again, you're talking about balanced lines. How the heck did we ever get on that topic?

I would appreciate it in the future, before you start spouting off, that you at least read my entire post and then not throw out a bunch of "facts" that have nothing to do with it. I was clearly talking about unbalanced audio lines when I mentioned RCA plugs, yet most of your post was about balanced audio lines which have absolutely nothing to do with this discussion.

That is correct.


That is not at all correct. There are many MANY RCA plugs from various manufacturers that are not at all designed to work with coaxial cables, because many audio cables are NOT coax. They're twisted pair.

For instance, Canare, one of the premier professional termination companies, has these very common solder-on RCA connectors that are totally unusable on coaxial cable:
http://www.canare.com/index.cfm?obje...5DA43EE99C3A24


Except in the thousands of times that it isn't at all. In the Canare connector as linked above, one conductor is soldered to the center pin contact, the other conductor is soldered to the outer contact on the RCA plug, which is the neutral/ground. That isn't a coaxial cable. You can't use that connector with a coaxial cable. And yet, hundreds of professional technicians use these connectors all day every day. How? BECAUSE THEY'RE USING TWISTED PAIR, and not coax!


Unbelievable. As an audio tech, I spend a lot of time MAKING these cables, that apparently you've never run into. Using connectors that are industry standard, that apaprently you've never even heard of.


Twisted pair cabling can be shielded, and commonly is.

But your claims that all RCA cables are coax is demonstrably ridiculous. Totally, 100% ridiculous.


Great. What's the relevance of this?


That describes a coaxial cable. Which as I already said above, was about the only thing you're correct about. And Kurt at BlueJeans also includes the qualifier "generally," because as he well knows, many cables used for audio signals aren't coaxial at all. They're TP.


Because you ommitted the second part of that sentence, which continues: "they're often not coax at all. " The point I am making is that there is no reason for audio cables to be a coaxial cable at a specific impedance because impedance is not a concern. And as a result, many audio cables are simply twisted pair which can be smaller and easier to deal with than multiple coaxial cables which can be more costly and more difficult to deal with. But apparently, you aren't even aware that audio cables can be made from non-coax cable.


That's the whole POINT. RCA plugs exist and are commonly used on cabling THAT IS NOT COAXIAL CABLE. Solder-on RCA connectors like the Canare connector linked above is such an example.

Or see this one: http://www.partsexpress.com/pe/showd...umber=091-1065

Or ALL of these: http://www.enjoythemusic.com/magazin...cashootout.htm

Or this ProAV Magazine article on how to solder an RCA connector onto a two-conductor (non-coaxial) wire: http://www.proavmagazine.com/industr...ticleID=597313

But you claim that ALL RCA cables are coax. This is flat, completely 100% wrong.


No, also they're commonly used for regular, unbalanced audio. Using the solder-on RCA plugs as just linked to. How do I know this? Because anybody who is at ALL familiar with audio knows this. Because I do this every day. Because I've torn apart consumer cabling because the connector came de-soldered and fixed them. Because some cabling manufacturers actually ADVERTISE the fact that they use twisted pair cable in their interconnects. And if you unscrew the connector body, gee look what's inside, TWISTED PAIR!


And how many times do I have to point out that you are completely wrong.


NO I AM NOT. I am talking about unbalanced, two-conductor RCA connectors that are terminated to wire that is NOT coaxial cable.


I used XLR as ONE specific example of the fact that audio cables very commonly are NOT coaxial cabling.

You are dead-set of the opinion that a cable with an RCA connector at the end is a coaxial cable.

You are COMPLETLY wrong about this.

How do I know this? Because making audio cables is part of what I do for a living. And I make and take apart and fix audio cabling and interconnects, SOME of which are coax, and SOME of which are NOT.

That's why if you go into an electronics supply house, they have RCA connectors that are solder-on, which are used for twisted pair, and they have RCA connectors that are crimp-on (of various sizes and types) for coaxial cables (of various sizes and types).

Your claim that RCA cables are ONLY coaxial is completely wrong.

There are several reasons you should read that link on balanced vs. unbalanced audio circuits (http://www.bluejeanscable.com/articles/balanced.htm). Here are a few:

1. It defines balanced and unbalanced circuits.
2. It explains why it is important to use unbalanced cables to connect unbalanced circuits and balanced cables to connect balanced circuits.
3. It explains why it's a bad idea to use twisted pairs when connecting unbalanced circuits.

The red and white analog audio connections are unbalanced circuits in devices such as CD players and VCRs. They should be connected with unbalanced cables, meaning coax. Here's another excerpt from the Blue Jeans site:


As I researched this topic trying to come up with links to support my statements (figuring you wouldn't take my word for it), I did find that there are companies using twisted pairs for analog audio cables that are intended to be used with unbalanced circuits. (The reason I've never run into this, apparently, is I don't buy overpriced cables that make unsubstantiated claims of better performance.) So, it appears that there are companies gouging customers for technology that sounds like it should be better, when in fact it is misapplied.

So, I was mistaken in one way: there are companies building audio cables that are not coaxial, but are intended for use in unbalanced applications that should be using coax. So, it indeed would not be a good idea to use the red/white RCA cables to make the digital coaxial connection. The yellow one almost certainly is coax and will likely work. Here's the kicker: I should have been right. All those red/white analog audio cables should be coax.

Brian you are correct, unbalanced low level interconnects indeed require coax. NOT for its characteristic impedance properties but rather for its ability to reject hi freq contamination. RCA or unbalanced ¼ instruments cables should not be twisted pair. Whether or not Chris can properly terminate them is another issue altogether.

flashbacks to the Air Force Base scene from "This Is Spinal Tap"

By strict definition, maybe all shielded cable can be called coaxial.


But, in a practical scheme? It is way easy to tell a true coax from just a shielded audio cable. A shielded cable will just have an oun inlusated wire more or less wrapped around a very thinly insulated conductor.

A coax will have a uniform un insulated sheath around a very specific / uniform thicker insulated cunductor.

Really just get the cheapest A/V cables you can find that have Red, White, Yellow on it and cut it apart. The yellow is obviously coax and the red and white are obviously just shielded.

A braided shield i.e. should increase the density or % of coverage, but a simple helical (shield) wrap still has an axial offset correlation to the center conductor.

Yes I've read it, and I agree with Kurt's explanations here. But that's not the point. The point is that you are NOT AT ALL correct that all RCA cables are coaxial. They simply are not. That's simple fact.

And indeed, if you actually read what Kurt says, and indeed YOUR OWN CHARACTERIZATIONS and QUOTES of that short article, it explains why it is preferred, generally, to use coaxial cables for unbalanced line-level audio. This directly implies the other option, and indeed Kurt explicitly mentions it: twisted pair wiring. This is not an uncommon construction for line-level interconnects for analog audio. That is ALL that I am saying. It is real-world, simple fact.


Should be is not the same as "universally are." Many times RCA cables are NOT coax, and that is the ONLY point that I am making. You can pretend the world is flat all you want, but that does not change the fact that twisted pair cable is not infrequently used to construct RCA cables.

And indeed, what you quote from Kurt explicitly describes using twisted pair wiring for interconnects.

I fail to understand how you can totally ignore both these explicit statements, and the various professional cable and connector examples I provided which are RCA and which are NOT coax.


You're darn right I didn't take your word for it, because it is objectively a completely ridiculous proposition when I have consumer and professional grade RCA cables that are constructed using twisted pair cabling SITTING RIGHT NEXT TO ME. There is not any way to support your statements, because they are completely erroneous.


Now will you admit that you were wrong about your above assertions to the contrary?


Not always the case. There are many reasons why twisted pair wiring can be preferred that have less to do with performance and more to do with resiliance of the wire and ease of pulling the wire. Full sized coax is very large, and if you need lots of audio runs, that's a big challenge. Mini coax over long distance is not the most desireable, but does help make the runs smaller, and bundled twisted pair is also very small and is usually a tougher cable. You can also run stereo audio on one very small twisted pair wire, which would require two separate coax pulls.

Additionally, coax can in some situations act as an antenna, and this can be a major problem especially in car installations, where twisted pair is much preferred for low noise when you're running a wire the length of the whole chassis. So coax isn't always the best solution.

My only point is that there ARE many times where RCA cables(and audio cables in general) are not at all coax. That's why you have to take care that if you need 75ohm coax, don't just blindly use an analog audio cable because it may not be 75ohm, and it may not be coax at all. (keeping in mind also that not all coax is 75ohm)


Again, that's not always true.


Again, not always. In reality, bundled cables usually are all the same, and if there's a video cable in there, they're probably all 75ohm.

But again, 75ohm cable is so cheap, it's hardly prohibitive to buy a cable to be sure.

First off, I never said that all RCA cables are coaxial. Here's a quote form my first post: Actually, any cable that is designed for audio and video with RCA plugs is almost certainly coaxial. It's pretty obvious that I was talking about the red/white/yellow A/V cables that we all have hanging around our house. You keep ranting that I am wrongly claiming that all RCA cables are coaxial. I never said that and even admitted in my last post that apparently there are some RCA audio cables out there that are built with twisted pairs. I admitted that. Why are you still harping on something I never said and certainly didn't even allude to in my last post?


He certainly does not imply the "other option". He explicitly states "Coaxial cable, not twisted pair audio cable, is the right choice when connecting unbalanced components.". There is no ambiguity in this staement. You should try reading and understanding exactly what he is saying before you start erroneously interpreting it. Twisted pairs can be used for audio interconnect: for balanced circuits. We are not talking balanced circuits here.


Am I the one who is totally ignoring what was said in that article? I searched that article for the word interconnect. It showed up once: This misconception sometimes leads to people using shielded twisted-pair balanced audio cable as an unbalanced interconnect. Which part of misconception do you not understand? He is saying that people are doing it and that they shouldn't be. He is not saying that it is an accepted practice, just that it is done and for the wrong reasons and that it is not a good solution.


If those cables are intended for use with unbalanced circuits, they are a poor choice.


Uh, I did. Which part of I was mistaken did you not understand?


I understand that there are times when it makes sense to run audio over twisted pairs. In fact, I am doing this as part of my whole house audio solution. But to do this with unbalanced circuits requires the use of baluns (devices which convert balanced lines to unbalanced and vice versa). I connect the unbalanced RCA cables to a balun, run twisted pairs (Cat 5 ethernet-type cable) to my destination several rooms over, then use another balun so that I can use unbalanced RCA cables to connect to an unbalanced input circuit.

If you are using twisted pairs to connect two unbalanced circuits (without conversion to balanced), you are not using a good solution.


I agree with you here. However, a lot of us already have dozens of these red/white/yellow RCA cables lying around. If you want to hook up a coaxial digital audio line and don't want to run to the store and buy another cable, you might want to try using one of these and see if it works. I did and it did.

That was your whole argument that I was addressing. You claimed that RCA cables are coaxial. That's simply not true. Big deal. Quit digging.


First, nobody is takling about balanced circuits except you.

Second, re-read what you just put in BOLD. Kurt is explicitly recommending using coax for analog audio interconnects and "not twisted pair audio cable". That "twisted pair audio cable" is the other option that anyone familiar with audio cabling will know about. You didn't know about that, but now you do.


Yes. And you're ignoring common sense. Kurt is saying that he prefers using coaxial cable rather than twisted pair audio cable. You were previously saying that all audio RCA cables were coax, and that's simply not true.


And I agree with him. The argument is not whether coaxial is generally preferred. The argument is whether other options, other than coaxial exist for unbalanced RCA interconnect cables. And they do. You weren't aware of that, it's not a very big deal, but you're not being very gracious about it, and now are dragging out a pointless argument with semantic ridiculousness.


And I agree. But that's not what we're talking about.


I don't know. Apparently you missed that part of your own post.


Not always is a balun required, but yes distributed audio over cat cable is common.


It's a very common solution. That's what many use for interconnects, and indeed that's what is often included in bundled bulk A/V cabling. It's usually not ideal, but it is common for cost and space reasons.


Thank you for being slightly reasonable.

I don't see why this was so difficult.

Chris, your latest post made me laugh. I'll start with the following quote: "You weren't aware of that, it's not a very big deal, but you're not being very gracious about it, and now are dragging out a pointless argument with semantic ridiculousness."

It's funny that you mention that I'm not being very gracious and that I'm dragging out a pointless argument with semantic ridiculousness. Let's review some of your quotes:

And you have no idea what you're talking about.
Your assertions here are ridiculous.
But your claims that all RCA cables are coax is demonstrably ridiculous. Totally, 100% ridiculous.
But you claim that ALL RCA cables are coax. This is flat, completely 100% wrong.
And how many times do I have to point out that you are completely wrong.
You are dead-set of the opinion that a cable with an RCA connector at the end is a coaxial cable.
You are COMPLETLY wrong about this.
Your claim that RCA cables are ONLY coaxial is completely wrong.
The point is that you are NOT AT ALL correct that all RCA cables are coaxial.
You're darn right I didn't take your word for it, because it is objectively a completely ridiculous proposition
Now will you admit that you were wrong about your above assertions to the contrary? (Particularly funny when this was in response to a post where I did indeed admit that I had been mistaken about an earlier assertion I had made.)
That was your whole argument that I was addressing. You claimed that RCA cables are coaxial. That's simply not true. Big deal. Quit digging.
You were previously saying that all audio RCA cables were coax, and that's simply not true.

Do you honestly think that there is anyone in the world who would be "gracious" after they've been attacked like this? I was actually pretty civil in my posts (comparatively speaking, anyway). You took every opportunity you could to blast me and I'm the one who is not being gracious? Hilarious.

This next one really cracked me up. I pointed out the fact that I never said all RCA cables are coaxial. You respond by saying: That was your whole argument that I was addressing. You claimed that RCA cables are coaxial. Wait a minute here. I point out that I never said something that you repeatedly accused me of saying and your response is to use the same misquote as explanation? It might have been reasonable to say you seemed to imply that all RCA cables are coaxial. I might have responded with something along the lines of that's not what I meant when I said It is not "semantic ridiculousness" to point out that you keep claiming, over and over and over again, that I said something that I never said. What does it take? I never said that. STOP SAYING THAT I DID!

Next point: you stated the following: nobody is talking about balanced circuits except you.

Why do I keep mentioning it? Because whenever I would search for twisted pair and audio, I kept getting hits on balanced lines and circuits. It was very difficult to find anything mentioning that twisted pairs are sometimes used with unbalanced circuits. As a matter of fact, just about the only hit I got that seemed meaningful at all concerning unbalanced circuits and twisted pairs is the one I linked to which explained why this is not a good idea. You kept harping on audio interconnects and how it's common practice to use RCA connectors and twisted pairs for these interconnects. Nobody, except you, was talking about anything other than the red/white/yellow RCA cables we all have lying around our house. You keep mentioning stuff that we're not talking about to refute something I never said in the first place. It's okay for you to keep mentioning things we're not talking about and for you to keep misquoting me, but I can't mention something that is material, the fact that twisted pairs make sense for balanced circuits, but not for unbalanced circuits? Rolling on the floor

I'm done with this topic. I'm sure that you will come back with something to refute most of my points. Can I ask one favor, though? Please don't say that I claimed all RCA cables are coaxial because I never did. Please?

Chris just likes to show off and upset everyone.

It's as simple as that Brian. All three cables are exactly same animal.. the only difference being the color of the RCA shell, they are beyond any doubt coaxial. Some of these sets will have a larger (yellow) cable, but still the remaining red and white are still coaxial. After 25 plus years, I've yet to note a single "twisted pair" cable used for the audio connection on those obligatory cheap set cables.

Brain FWIW just like yourself I was given a long painful dissertation by Chris regarding (video) IRE units and in the end come to find out this forums resident expert (Greg Rogers) explained to Chris that IRE are NOT simply analog volts and told Chris that IRE is the more powerful tool for describing image information.