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Phantom Power - What is it?

(Video transcript) Hi, Paul Donovan here. from avtechnician.ca your guide about tips and tricks on Youtube.

One of the things I found when I first started doing professional audio as an AV Technician, was there was a button on the mixer that said phantom power. I thought, wow, do I have a "Phantom of the Opera" thing going here? I don't know. But as an AV Technician I'm supposed to know everything so I did some investigating and I found out what it all was about.

There are many microphones on the market various types of things that do many different things. But what I discovered is some times microphones need a little bit of power. Yea, you say, well sure, ok. There's power running through the wire, right? But the thing is that they need a little bit of extra power to operate. Sometimes you can get a microphone that has a battery in it. Sometimes a little button battery or even a triple A or a double A. Then other microphones that need power but the only way they can get power is by being plugged into your mixer board.

If you're planning to plug your microphone, or anything, and you are only using a 1/4" unbalanced connector, or possibly and 1/8" connector if you are plugging it into your computer. You'll find that most of those microphones don't really need electricity other than what happens through the natural process of the vibrating head on a microphone. Sometimes those microphones will have a built-in battery. These types of microphones, sometimes called condenser microphones, they have built-in batteries.

If you are going to connect the microphone to your mixer and you're using a microphone, say something like this, this is a microphone that connects up using the XLR connection. Likewise a microphone something like this that hooks up again with the XLR connection. These types of microphones wish and desire to have a little bit of extra of juice in the form of phantom power provided by your mixer.

You'll notice if you are looking at your mixer that there's quite often a button. This button is there there to turn the phantom power on or off. If you have some the larger mixers you might actually have a button that independent for each of the microphone channels. Phantom power is only passed through the XLR channel, the balanced cable. of an XLR connection. Generally speaking you do not get balanced power running through a 1/4" jack even if you do have a balanced TRS jack. You often do not see phantom power running through those jacks.

A slimline microphone such as this, sometimes called a gooseneck because it's flexible. Sometimes you'll see gooseneck microphones generally speaking they need phantom power. Also a similar type of microphone you might see, is a choir microphone. I'm going to be talking in another video about choir microphones and how to microphone a choir or acoustical musicians. For now we are just going to talk about the phantom power that is needed for things like the slimline microphone.

Some studio microphones, those ones that stand up you see in studios they also need some form of power. Often times they have built-in power because they are very specialized and they want to control the source of the sound and they don't want to pass any unusual sound.

On your mixer board you probably have a single button that turns the phantom power on with a little red, or in my case I sometimes see blue. Or you might be lucky to have a mixer board where you an individual button that you can press to provide phantom power to individual microphone channels. That is really handy when you are trying do something where you might have microphone devices that would have actually have difficulty with have phantom power.

One of the most classic examples of a microphone that typically gives trouble with phantom power is a thing called a PZM, or some people call them "perimeter", microphones. Perimeter microphones, it's about a 50/50 chance whether it going to need phantom power or not. I have found that it's best to check it out carefully, turn the phantom power on and see if it works. If you need to run phantom power on everything, you only have the single switch, then you need to be cautious in case you do have any microphones that are sensitive to phantom power.

Another microphone that you will often will see is like the shotgun microphone that used in the movie industry or film industry, or the new reporters. Often times these microphones have batteries in them but they also have a little switch on the side that you can turn the power on or off as well as different impedance levels, and so on. Often you'll find shotgun microphones that way.

There's another type of microphone called "push and talk" microphone. This one yes, they come in a wide variety of quality of microphone, especially on the push-to-talk switch If the microphone requires phantom power and you didn't pay rock-bottom price for the microphone, the push-to-talk microphone you probably won't have any trouble feeding phantom power into the device. What they do is the push-to-talk cuts the other channel that doesn't cut the power. Basically the idea of the push-to-talk button is to turn on and off the microphone. Some of the cheaper ones when you do the push-to-talk it cuts both the phantom power and the signal for the microphone. Everytime you push the button you get a little tiny crackle. Quite often that's sign of having a low-quality microphone or quite possibly a microphone that doesn't actually need phantom power. And you are are feeding it phantom power, thus creating the potential for the crackle of even a short-out.

That's the sort-of the history. It's 48 volts of power running through the wire, at very low wattage, it's not like you're going to get electrocuted. It's important to remember that generally speaking, for myself anyway, when in doubt turn on the phantom power. I find in almost every situation that I go to, when I'm doing sound, I find that I need the phantom power more than I don't need it. That's why I always say, if you are in doubt, turn it on. I can remember doing a couple of events, this is a bit embarrassing, but I've done a couple of event where somehow accidentally the phantom power has gotten turned off. Especially on mixer boards where it's just a single button. I'm like, what's going on, the microphone on the lectern is not working oh no! I run up with a wireless handheld microphone and hand it to the speaker. I'm so embarrassed, so unprofessional. allowing my equipment to fail. I walk back to my mixer board and I see that the light's off, and Oh no!! It's really embarrassing. It's really embarrassing. Always keep an eye the things like phantom power , if they are on, that they don't accidentally turned off. If they are off and you're not getting microphone working, turn it on and you'll save the day.

There you have a brief summary about what is phantom power. This is Paul Donovan from avtechnician.ca Please check out our website at www.avtechnician.ca Subscribe to this channel to keep up with what's happening in the world of AV technicians. Thank you for watching.