RF in microphones. What is it?

Already history story. Welcome, already history story Welcome. Hi the Pro Audio Suite. Those guys are professional and motivated with text. The video stars George Whittam, founder of Source Element, Robert Marshall, International Audio Engineers Darren, Robbo Roberts and Global Voice Andrew Peters thanks to Tribo Oustry and Audio Making Passion her Source Elements, George, the tech Wism and Robbo and APS International demos. Find out more about us check the Pro Audio Suite dot com. And of course don't forget the code t R I P A P two hundred and that will get you two hundred dollars off your tribooth. Now we're going to talk microphones today because there's one thing I don't think we've ever discussed, or not in depth anyway, is RF on a shotgun? Mike. Now, I'm assuming our refuse radio frequency, but I for anybody like me, what does it act really mean? And should it be something that we consider when we're buying a shotgun? Mic E mean in fact that the microphone uses what they call an RF technology? Is that you're referring to? Yeah, you know, I I'm sure I'm sure Robert would know more about the they details without me having to google it. I've read about RF microphones for a few times, and I think one of the side effects of a MIC being RF technology, which by the way, has nothing to do with transmitting a radio signal, right, it's the ability for the microphone to reject noise. I don't know if I've ever heard of a four to sixteen, for example, which is using this RF technology as having an issue picking up radio frequency noise. If anybody else has heard of that, you know, if you've had a mic for sixteen picking up RFI, let me know. But on the one of the advantages of that technology is it's very highly immune to humidity. Yeah, that's what I heard. Yeah, And why that exactly is is definitely beyond my pe grad Isn't it something to do with the way inside the microphone that each part talks to itself, like talks to each other. It uses like a radio frequency inside the microphone to communicate with itself. That's my recollection of what it actually is. That that is certainly plausible. I just wish I was more understanding of the technology, and so we're talking about it rejecting radio frequencies. Is that we're saying like a shielded cable would reject. It's like, yeah, I think that's what it does. If anyone's listening, we should do what everybody else does on their YouTube things. Can leave us a comment in the comment section. Can I do story time and read it? Yesty too, I'm sitting comfortably, George, rate it in your best bedtime story voice. George, okay, yeah, well it would have to be in a German accent. I'm not going to do that a bedtime German accent. Yeah. No, that's scary. That's really scary. Actually. But there is a whole white paper from Suneiser and it's written by Manfred Hibbing and it's sendheisas professed MKH condens a macrophone. Sorry, sorry, sorry, sorry everybody, I'm sorry. But basically what it says is that high RF frequency solves a problem. So when the replacement of electronic valves by transistors commenced at the end of the fifties, this change was also under consideration for condenser microphones. Reduced size, low supply voltages, and lower power consumption were regarded as great benefits, as well as being able to use simpler microphone cables. However, there was a basic problem. Direct replacement of the valve by a transistor was not possible due to the mismatch between the high impedance of the condenser capsule and the low input impedance of the transistor. Hence, for optimal matching, the capsule impedance needed to be drastically reduced. And then they go on to explain the impedance of capsules, et cetera, et cetera. So down to the next paragraph. How does RF microphone technology actually work? The principle is simple, after all, that yeah, sound waves deflect the diaphragm of the condenser capsule and change the capacitance between the diaphragm and the nearby back electrode or backplate. Contrary to the more common low frequency AF condenser method, the capacitance variations are not converted directly into audio signals, but modus a high frequency radio frequency signal generated by an oscillator inside the microphone. This signal is then immediately demodulated inside the microphone, thus recreating the audio signal, but with a very low source impedance that is well suited for driving a transistor amplifier. Thusly, an RF condenser microphone is basically comprised of a transmitter and a receiver that are directly wired together. The RF signal is therefore kept inside the microphone. Only the audio signal is applied to its output, just like all other microphones. So, yeah, what you were saying was pretty much correct. I mean, that's what's going on for me. What happened he picked it up through us Moosa somewhere along the way. That's Can I just say, Robert would make that a lot clearer? Yes, yeah, sure. The thing with humidity, and here's a little paragraph about this, there is no other important benefit of the RF principle for practical use the low electrical impedance. So the capat capsule provides outstanding immunity against detrimental effects due to humidity, because even then the leak resistance is very much larger than the capsule impedance. Thus, MKH microphones, which I understand, all of those, the all MKH mics are RF mics, are they're well suited for outdoor use. So this is why MKH mics no matter whether they are the MKH four four, one, five, forty one six and I'm paraphrasing here, or any of the MKH stuff like the MKH forty. There's the eight thousand series, right, they have the eighty third, eighty twenty, eighty thirty, eighty forty, fifty, eighty sixty, they have a whole new line. All of them are using this technology and the reason for why it still persists to this day is it's excellent outside and thereby it's also excellent in a sweaty, hot, muggy voiceover booth. If it's full by three by six, yes, actually it's four three by six absolutely. Yeah, talk about that outdoors though, because this was something else where that I got stuck in the rabbit hole I mentioned before we started recording. Then there was a discussion about using shotgun mics inside. Now this is a basically for drama and stuff like that. So a boomop using a mic where they wouldn't use a shotgun inside, they would use a pencil, small diaphragm pencil condenser. Yeah. Now, if that's the case, if you're a field audio guy, why would you not use a pencil condenser as a voiceover person inside? I don't know. I did have a pair and I still do have a pair of pencil condensers. The classic octava yep. Mics that are so popular yep. And I used to use them to try to do field recordings and I didn't know about much about mics at the time, and I would get the dreaded we sometimes call it motor building. It was like this yeah, yeah, ye, you know, fluttering sound, you know, yep. And I didn't know why it was happening. I just knew it would happen, and it would always happen if I was outdoors, and sometimes I was like in a really humid environment and it would get really bad and I was like, oh no, the MIC's bad. And then I'd bring the mic home and I'd pull it out of the box later and it would be perfectly fine. Yeah. Yeah. So, because the AF microphones are audio frequency condensers, because they store a charge high on a high impedan's capsule, it's easy to for that charge to find a way and leak across the insulation by riding on water molecules, which caused those motor boat or crackling effects. So I don't know, I mean, I think there's it's just another added benefit of an RF mic is that you just you're just never going to have that that problem. But you know Neiman large diaphragm condenser mics where you have two diaphragms extremely close to each other. Even if it's a cardioid, there's still too there's a capsule. There's the diaphragm in the front that takes the sound wave, and then there's one in the back that picks up the signal. Yeah, creating the changes in capacitance. Blah blah blah. And that is just theirs are so close together that water molecules actually transmit the electricity. Yeah, so create the static. Yeah. Do you know anybody who does use any a pencil mic for doing voice in the I mean I know people that use eighty the eight eighty series or the eight thousand series, But those are mkh mics. So I believe all the eighty I believe all the eight thousand series mkh mics are also RF. Is that the ID fifty is that like the eighty fifty, eighty forty Yeah, yeah, eight twenty eighty thirty are tiny little stubby capsules. I mean they are mini because they they've just I guess they have the most condensed electronics, and boy are the expensive. Yes, well, this is a stereo set. So I'm looking at twenty eight hundred for a stereo set, So don't look at the ships then, yeah, right now I know CHEF six to another level, right, yes, but yeah, the MK forty is going to be about fourteen hundred US. So you know, if somebody is comparing mics and they look at this minuscule, laughably small mic and then they think, why would I ever use that over for sixteen Well, that's because it doesn't have the negative effects of a shotgun microphone. Yeah, it doesn't have any of the negatives. It doesn't have It doesn't have the negatives in terms of off off axis phase problems. Yep. You get a way more accurate pattern as you go off axis, right, So that's one reason it's certainly very very nice to work with because it's so small. Yeah yeah, so it's never going to get in the way, but it's extremely they're going to be extremely pop sensitive, right because the capsule's right there at the grill, it's right in the front like any pencil mic. They work great on voice, but they pop like a mofo. Yeah yeah, yeah, they pop really back. So you have to have a good mic technique and maybe a good pop screen yep, but they are quite an upgrade. Some really have found them. It'd be quite an upgrade, like an eighty to forty from a forty one six. Yeah, so yeah, I would go with the eighty fifty because that's a super super cardioid. That would be my choice. Yeah, if I was going this direction. Yeah, it's interesting. It's funny with shot guns. And we were talking about this also before we jumped on, because the road kit I set my daughter up with for her travels. I gave it the NTG three and we were just doing some testing a few hours ago just to make sure that an rf mic too. I believe it is an rf mic, But it also so it's quite bottom end, you know, it's equed very differently. Yeah, a very different tone from the forty one sex, which I think for location it's perfect because the further you get away from the source the sound source, the thinner the audio gets. But if they've got that sort of hype bottom end, it actually keeps some of that in there, you know, in the sound, which is great for that kind of work. But it also sounds really good on a female voice. I mean, she sounds great on that anti G three. But if I when I put it up in front of me, I have one for a while, and it's central huh just to me, Oh it was yeah, it wasn't good. You lose articulation and it doesn't have a crisp attack. It's very Yeah. There's another mic that's really popular because of its price point. That's the Sinko D two. Have you heard of that one? No very cheap shotgun mic. And of course it looks a lot like a forty one sex same color, same sheepe, same size, same everything. Yeah, so of course it gets sold all over the Amazons and stuff as a cheap forty one six, But it sounds nothing at all like a forty one six, nothing at all. It's a very very flat mic, very flat, very dull. So when somebody sends me that sample, I know immediately I'm gonna have to help help the top end. And when I do that, up comes the noise, you know. And that's the other problem with small diaphragm mics. Making a small diaphragm pencil or shotgun mic sound as low noise as a large diaphragm mic is no small feet. It's very difficult to do so that's another problem, like if you you're never going to get a small capsule MIC to be as quiet from a self moist perspective as as you will a large diaphragm micah, even a cheaper diet like well, let's look at the Road NT one four are so dB self noise. You're never ever going to find a small diaphragm MIC with that kind of a measurement. Yeah. What's funny is I'm reading the specs right now now from the Saniser MKH eighty fifty. They don't even quote the self noise interesting, which to me is a way of saying, he's so great, but it doesn't matter. This is a location mike. You're going to use it outside, so it doesn't need to be that quiet. Yeah yeah, but still it's a fourteen hundred dollars MIC and it they don't they don't quote the spec so that I find that kind of fascinating. Yeah. Yeah, but you know, if you're buying a shotgun, and I we've banged on about this before, but I still reckon the best value, the best bang for buck in the shotgun. Any shotgun MIC is the NTG five from Road. Yeah, it sounds like they got over there. Yeah, they had some growing pains with that. I did. You definitely had a few people with some issues. It seems that that has been sorted because I haven't heard of any of those kind of complaints of noise or whatever for well over a year now. It's been, yeah, a year or two. I was a victim of one of those. I had the first one they sent me. I had problems with, but sent it back and got a brand new one. So and you haven't had anything since. And and full credit to road all I ever ever had a problem replacing them moment. Yeah, and yeah, full credit to road. All I sent back was the actual mic and I got a whole new, whole new kid when they sent me back the new one. So yeah, you know it's typical of road really. Yeah. So you've got nice little shock mount for your forty one six, I know I've got. Yeah, I've now got two of the shock mounts, which is kind of nice. Well, those are cool, man. If I were if you were to go buy those pistol grip shark mounts with the ryecoat style liar mount and everything, theo's are going to be one hundred dollars plus yeah, easily, easily so and then the wind screen and everything else. I mean it's like one hundred and fifty dollars kit plus the mic. Yeah, and I do like it. It's standard fair in my in my room here that or the or the Austrian audio one or the other of the two. Yeah. Mine pretty much lives permanently my my kit, you know, for going on the road and traveling. It had a Pelican hard case and the ten G G five lives in there. Yeah, you know, it's just always the ready to go. Yeah. Well, you know what I need to figure out now thinking about that is, uh is cutting the phone in the in the road kit for my my English channel so that the NTGI fits in there and then I've got it only one case. That's what I need to figure out. Yeah. Oh yeah. It seemed that there was there was enough space in there to squeeze in the shotgun mic absolutely to speak up the bag and be a sick kit. Oh fantastic. Yeah, Well I did actually dig around and I went on the recording recording hacks website, which is a great database of microphones recording hacks dot com. And while it's missing, MIC's here and there, for sure. It does have pretty much all the Noymans and Syndheisers and the bigger brands and stuff. And I found the eighty fifty and they actually do list a self noise rating of thirteen dB A waited. So the senas are for sixteen is like sixteen I believe. Okay, so they managed to shave three d B of the sophomoise. I think the nt G three is about the sign a boy twelve to thirteen, remembery, Yeah, that's that's good. I mean it's going to be hard to find a lower value than that. I haven't seen. I mean maybe SHEPS has something quieter. Possibly, I haven't looked. But uh said s c h o E P P. Is that how you spelled? Thinking? Am I thinking of the engineer and all that? Is it double pay? Well? Yeah, it's annoyed. It's confusing because you have the mic called sheeps, yes, and you have the engineer and they're not spelled. I can't remember whether it's double pay for the engineer or double pay for the mic. It's one one of them has two. I guess that KEZ guessed right. It s it's s A s c h O E P s oh yeah, show ups, Yeah, show ups. So the CMC five, which is one of the quintessential chips shotgun Mike is, it's got one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen different capsule options. Wow. Good the hell? Wow? They have this huge array of capsules that thread onto the body, you know, depending on what you're doing. So like, let's look at a let's look at a cardioid. Let's look at a super cardioid, the MK forty one. It does not list a noise spec. Yeah, I can't. There's no noise spec listed anywhere there. So that's really yes, kind of old school, isn't. It's like the old CMV microphones from Noyman back in the well would have been thirties forties. Well, you got the bottle and instead of having a switch to go from cardiod figure right to omnia whatever, you unscrewed the capsule and put a neat capsule on the top, right. Yeah yeah, yeah, Well actually, my my mkh are my sorry, my my octavius, same deal. You have three capsules per mic, but that whole kit with two mics and all the capsules costs less than one of these capsules. Yes, you know, you start realizing the difference in cost is pretty stark. I mean they said the capsules are anywhere from eight hundred dollars to fourteen dollars for one capsule. So yeah, I do like the idea of the ship's the shotgun that's blue. I mean, if you had that in the booth, and as soon as you see that color, you go, oh okay, somebody serious. Yeah, yeah, yeah. Have you ever seen their V four U model? It has a blue bottle and then the grill has this very cool deco style grill. It's very cool looking. Look it up sometimes, what's what for you? It's a neat looking mic and it has a quirky, quirky thing. It's that the capsule has a small, slightly hinged head, so you can tilt the capsule forward and back a little bit, you know, like ten degrees twenty degrees. Oh god, that looks good. But it's a cool looking mic that is very tasty. Yeah. Yeah, don't google robber, you'll get your bloody machine. Well I'm doing it on my iPad, but it's not insane. There's some problem with the website and I can't get on there, so I don't know what's going on. And yeah, V four you is a three thousand dollars uh yeah retail And then it has a pretty flat response curve. I mean it has a small presence rise at a four K, which is typical, you know, but it's only like two or three dB rise, so it's pretty flat. That is insane. It does. Remember trying it at one of the nams or whatever and being like, well, that's a cool that's a cool sound in mic. It looks really neat, very taste. Oh that's how much of coss ok, that's funny. Yeah, I might get one in the next lifetime. I was in Tokyo and I saw a Dunhill store and I went in there and they had these linen bucket hats and caps and stuff. I thought, wow, that really cool. And I was looking at the price and tried on the bucket hat and it's like yeah, yeah, yeah, I'll get that, and so I said, I'll take this one. I said, actually I might even get the cap as well, and the guys just looking at me, going, no, you don't need the cap as well. You don't just take this hat. That's all you need. I'm like, really putting yourself out of a sale here, Okay, whatever. So I bought the thing and I'm walking back to the hotel and then I'm doing the calculation in my head and thinking I just got a bargain of thirty five bucks. I saw, Hang on a minute, I got the digital point in the wrong spot. I just paid for zero three hundred and fifty bucks for a bucket hat. Yeah right, dear, oh dear, oh dear. Anyway, yeah, groops, was fun? Is it? Over the pro audio Suite? Thanks and Austrian audio recorded using Source Connect, edited by Andrew Peters and mixed by Robo. Got your own audio issues just ask robo dot com. Tech report from George the Tech Window. Don't forget to subscribe to the show and join in the conversation on our Facebook group to leave a comment, suggest a topic, or just say today, drop us a note at our website audios dot com.