What Makes a Microphone Directional? Part One

Y'all ready to be history? Welcome. Pro Audio Suite. These guys are professional. They're motivated. With Tech to the VO stars. George Whittam. Founder of Source Elements. Robert Marshall. International Audio Engineer. Darren Robbo Robertson. And Global Voice. Andrew Peters. Thanks to Tribu. Austrian Audio. Making Passion Heard. Source Elements. George the Tech Whittam. And Robbo and AP's International Demos. To find out more about us, check theproaudiosuite.com. Line up, ladies! Here we go. And welcome to another Pro Audio Suite. This week, we're talking microphones. A quick recap, firstly, on the... We never. Talk about microphones. I know, it's ridiculous. We need to do it more often. We should, really. This is the M92. 1S that we tested with three other microphones a couple of weeks ago. We had the C414EB with the nylon CK12 capsule. We had the OC818 from Austrian Audio with the ceramic... CKR12 capsule. We had the Microtech Gafel M930 Art, which I still think is actually an M7 capsule, but only connected in the front of the capsule. The jury's out on that one. Only connected one of the two sides, basically. Correct, yeah. But some people are saying it's not, and some people are saying it is, but it's definitely PVC with gold, so that tells me it probably is an M7. And then the Gafel M92. 1S capsule, which is a tube mic with the M7 capsule, once again, only connected to the front of the capsule, not the back of the capsule. And that's what I'm on now. And last, when we did the shootout, this thing came last. And I thought the tube was gone, or the valve. And I was correct. So that's been changed. And that's the one that everyone liked. They liked it when it was broken, yes, indeed. With the broken tube. Broken. Broken mic sounds great. Anyway, so this mic currently is running through a Neve 1073. It's on 30 in gain, and I'm doing about plus 4 dB in the trim, I think, from memory. And also to add a little bit more niceness, I've got it going through the 2254R, which is a rack mount version of the 2254 from Neve. So this is what it sounds like with the new tube slash valve. So what do you reckon? Better voice on it? No, I'm sorry. The silence says everything. It sounds good. It sounds natural. It doesn't sound sharp like a 416, 416 I mean. Pretty smooth, yeah. And it doesn't have that thinness that was happening before. I thought before with the bad tube it sounded really thin. It is because that was the issue. That's why it got all sparkly and nothing in the sort of low mids or anything. But now I think it's back. Anyway, that's what it sounds like. I shall now vacate the booth and head back to where I was before. Ladies and gentlemen, Andrew Peters. And I'm back. There we go. Oh, yeah. I'm back. I'm back. I'm back. So, yeah. So that was the Microtek FL with the new tube. And now you don't want to sell it, right? Exactly. And it's really funny. We also talked about the M7, and I guessed that Neumann were buying M7s from Gefell because they don't have the tooling to make them. Since found out that they don't have the M7 anymore. So if you send in your original U47 and it's got an M7 capsule, they'll replace it if it's not working properly and put in a K47. Oh. So there you go. What if they retuned the electronics to change the EQ of how that capsule sounds? Well, I mean, there's not a lot of electronics in a capsule, really. Well, not in a capsule, but I mean, don't they have to compensate for that in the circuitry design? I think they do. I think they're copying the sound of the M7. How does the history of a 47 go? Is it like there used to be 47s obviously with M7s, and then at some point they made 47s with K47s? I think it was like in the late 50s. Yeah, I think the late 50s they got rid of the M7 and jumped across the K47, from what I can see. I mean, all these capsules are so similar. For example, when I had my 87 converted to a 67, and the difference was between the K87 and 67 is really just the distance, because the 67's got more voltage, being a tube capsule. And less voltage for the 48, so for the 87, so that the plates are closer together or farther apart. That's the basic difference, I think, mainly between a 67, K67, and K87 capsule. I have no idea the difference on a K47 capsule, but probably all these are like subtle generational changes. Yeah. Interesting, though. Anyway, so the only real M7 capsule now is made by Microtech Gafel. That's it. Can you tell Neumann, go get me a real one and put it in when you Fix my mic? I wonder. I wonder if you asked them that. I bet they wouldn't. What capsule is in the M50, by the way? That mic is stupidly loved by classical recordists. I thought that was the M7 as well. It might be. I'm wondering. Let's see here. The M50 uses, guess what, the KK50 capsule from 1951 to 1954. Oh, okay. Then they later switched over to the K53 capsule. which the K50 capsule must be very similar because it's sputtered with PVC diaphragm. Oh, okay. It is PVC. I was going to say, is it my law? Because, you know, I mean, there is a big thing about the degrading of the M7 capsule because of the PVC. But I did hear that if you look after the mic, don't do anything silly with it. Keep it nice and clean. It should last for decades. So basically you have a now refreshed cardioid, hybrid between a u67 and a and a u47 it's like you have like a u it's not a u57 because we've seen that too so it's like it's a it's a u half and half or maybe that is what a u57 is what was that the u57 was 12 volt power that's what that was that crazy 57 or 77 the 77. Was 12 maybe it is a u57 77 was 12 volt yeah That ran on batteries, which is really weird. And I was talking to someone the other day about that. I said, I'd never heard of a U77. And they're going, oh, yeah. They seem to think, yeah. But the weird thing is I saw a tour with Rick Beato and Warren Hewitt. They both recently did tours of the Neumann factory. And they've got all their classic mics in the front and on display. Do you know what's missing? A U77. Right. He had everything but that. Which is weird. I mean, that's rocking horse shit, the U-77. I think they only made maybe 400 or 500 of them. What's the UM-57? Is that what you have? The UM-57, well, mine is kind of, it is the UM-57, a new version of the UM-57. Yeah, it makes sense. So the UM-57 was made in 1957. Yep. And features. All the good things were made in 1957. Features the M7 capsule and probably... Let's see, what tube did the UM57 have? EF86, I think you'll find. No. The EC92 vacuum tube. Oh, really? Interesting. But they replaced the older EC92 with a premium EF86 pentode tube. Yeah. So if you're looking for a modern high-end reissue of the microphone, such as the one produced by Microtech, the one that Andrew has, They replaced the older EC92 with a premium EF86 pentode tube wired in tri-mode. There you go. This update was chosen for its exceptionally low noise, though we might like to argue about that. Yes. And stable operation in modern student environments. Yeah. So, yeah, you have this, like, Because we all know that the U67 is famous for the EF86 tube. So you have this kind of in-between U47, U67 microphone. And the interesting thing is the transformer inside the microphone is the same as the ones used for the C12. Oh, and so it's even more... Because the U47 used that famous unobtainium NuVista... What do they call it? It was like. It was a weird tube, and you can't get them anymore. The VF41 or something, the VF something. And it's literal unobtainium, I believe. You can't get them. Or maybe you can, but you'll spend a lot of money on one. Yeah, I was surprised how relatively cheap new tubes are. Well, kind of. Here you go. Ready? So I'm looking here. Telefunken V14K tube. Price for the tube, that's it. $ 995. Jesus. An EF-12 tube, which I don't know what it is, but Peluso makes an EF-12 tube, and that's $ 406. Or you can get an EF-86 tube for $ 35. Yeah, but I mean, are those tubes actually manufactured by those two companies, No, these are all. They're sourcing them from Russia, right? They're sourcing them, yeah. So when you buy a really cheap piece of tube gear, and they still exist, MPA, this and that, Project Studio, whatever, are those tubes coming? So most of that cheap tube gear is running the tube, they're running them on low voltage. So they're not really running the tube in the proper. To really get the good out of it. And they're using like a 12AX7 or something? It's not even that. There's nothing wrong with a 12AX7. But I mean, they're running usually off of either a USB or a wall wart. So they're getting like an amp, two amps maybe of current. So what you're saying is. It's called the starved plate. Starved plate, okay. Yeah, that's the way they do it. And that's what makes the construction cheap. Because the money a lot of the time is in the power supply. Yeah. So they're not really getting the full mojo out of these tubes because they're not really running them with the proper voltage. And so the tubes never really go into any kind of harmonic distortion per se, right? Or if they do, it's not a very pleasing distortion. It's more of a.... I don't know, you know, because every time I see one of those in someone's studio, I systematically unplug it and throw it in the trash. So, I never really get to hear, you know, what they sound like at the edge, you know, because all they're doing is adding noise, it seems like, half the time. Correct. So, basically, my understanding is that it doesn't have the same headroom or it doesn't distort in the same way. It just clips more with the starved plate. Yeah. Yeah. You know, like tubes are known for distorting at the even harmonics. So it's very pleasing. It's basically distorting at the octaves. And so it sounds really good. Whereas chips, I believe chips distort at the third harmonic, which is kind of more in harmonics. Yeah, it's even order versus odd order harmonics, right? FET circuits distort or have odd order harmonics that don't, quite sound as pleasing to the ears. Which is less musical. It sounds more ugly, for lack of a better word. Yeah, it's just enharmonic, literally, or less harmonic. I mean, technically, the odd harmonics are literally in the harmonic series, so you can't say it's enharmonic. But there's nothing more harmonic than the octave. And so with the even harmonics, you're definitely, the first harmonic is, I think it's the octave and then the fifth. I forget the series, but. An octave, then the fifth, then back to the octave. It's a harmonic series. Right. Well, I'm using a tube valve preamp at the moment with this microphone, so that's what you're hearing on this one. So this is tube on tube? No, no, this is the CCA on the tube. I'm sorry, this is the CCA on the tube, yeah. Yeah, yeah, yeah. So it's just the tube and the thing. I wouldn't do tube on tube. I think that would be double tube. Well, where does the tube... It's like double denim, I guess. I mean, since we're talking about tubes, we'll go there. Where does the tube matter more in a signal chain? In the mic preamp? I'm sorry, in the microphone's internal electronics or in the mic preamp? That's a good question. It is. Because my feeling is like, you know, because with a microphone, because you're not able to adjust the input gain before the tube, because that's designed into the circuit, then how can you find those critical input levels for a microphone's tube where it can go into harmonic distortion at a pleasing amount. I would think you'd have to pick a tube mic that is suitable to the source. So if the source is loud enough, then you get that nice sweetness out of that tube. I think invariably the tube in the mic has to put in more color just because that's the first big jump in gain. Yeah. It's just closer to the source, and it's doing more of the heavy lifting, getting it from microscopic, unmeasurable levels up to at least something that the preamp can boost up. By logic, wouldn't that the tube inside the mic vary its amount of harmonic distortion pretty heavily based on the input signal level with SPL coming into the mic? Which I think is the point. So if your input SPL is below, say, 100, maybe it's not doing anything. Oh, you're saying that because inside the mic, it's kind of running at a fixed gain. Right, so it's going to depend on how loud the input source is. So if it's spoken word, which could be between, what, 70 and 90 dB or something, depending on the distance, et cetera, is the tube ever even going into over. I guess you've got the pad, but you're right. Like a preamp, you know how preamps have an output? attenuator, actually, is what it is. Because the nature of a preamp is actually that you run full amplification, and then you roll it back. There's only a few amps that run. With what's called true gain. And so between cranking it up and then running the output down, you're able to kind of dial in the color and ride somewhere in that line. Whereas with the tube inside the mic, you're getting what they designed it to do, and that's it. There is no smooshing the paintbrush against the canvas. Yeah, that's a good analogy. Like the LA-610 I was just playing with today, but in the virtual sense. A client of mine had one in her signal chain in her Apollo, and that's got three different level controls on the preamp. It's got a 5 dB step input gain. Which preamp emulation is this? The 610. Yeah. The UA610. Yes. So it's got. Minus 10, minus 5, 0, 5, 10. And then it's got a level knob, a large level knob. And then it's got an output. It's made out of computer bakelite. Yeah. It is. But what I'm saying is I don't have these things in the real world. So I don't really understand how these are designed topologically. I would imagine if you look at it from trying to achieve the same gain, like if there was enough gain on the... find control that's after the big one, and I don't know the 610, but if the 610's first knob is the input, and you crank it hot, so you have like, say, plus 25, and then you run the other side down to negative 10, so you're ending up with 15 decibels, it would probably have a different sound than if you ran the front side at plus 10 only, and then the next stage at plus 5. They probably have a different color to it because one of them you're overdriving it and then pulling it back. The other one you're. Just kind of... It's like the Neve because the Neve has the gain, which is the input, and then the trim, which is the equivalent to a fader on a desk. So it's the output. Is that what you were talking about before? Yeah. It's two stages. They're referred to as stages. Yeah. And one's like the input stage, and basically you. Have the input stage and the output stage. Well, the UA-610 has three stages. That's what I'm saying that's unusual about it. It has a five-level switched gain. It's stepped. So it only goes from minus 10 to plus 10. That is your whole gain range. That's it. That's what you have to play with. And then it has the level knob, which goes from minus infinity to 10. And then it has... An output fader. That's a fader. Also. So, I mean, I never touch the output fader, but I can never figure out a reason why to. And do all the knobs have gain on them, or is the output fader like zero at the top? No, the output fader is zero in the center. In the center. So it has gain on it, in other words. Yeah, you can add or cut gain. And the level knob is the only one that's a true level fader that goes from zero to ten. So it's a little perplexing. And what makes it even worse for the actor is they're so used to grabbing the gain control on the Apollo. And when you turn that gain control, by default, it does the minus five, minus seven. It only gives them five steps. But if you hold down the preamp button, which I didn't even know this, guys. I've been using this thing for a long time. And my client today literally shows me, well, if I hold the preamp button down and then I do this, now it lets me adjust the level knob with the knob. And now it lets me adjust the output knob with the knob. Oh, you're talking about the preamp. It's not the preamp button. You're talking about the do everything knob on the front face of the Apollo. I think that's what it is. Yeah. Yeah. Yeah. It's the, what button. Have I pushed before I turn this knob? Which is so confusing to use, you know, for many people, but. Anyway, she said, look, I can adjust that level knob with the knob, but it doesn't remember that I want to adjust that level knob with the knob. So every time I want to adjust it, I have to go in and fiddle with the settings every time. I'm just like, that's. Push it down. No, that's, that's too much for actors to think about. Yeah. And she's like, oh yeah, I'm writing the gain all the time. I'm just like, holy smokes. That's, that's a lot to think about. No, just, just don't write the gain. Just. Keep it low and trust that 24-bit has a crap ton of headroom for you. That's what I'm trying to tell people now. Again, a lot of this is traditional engineering technique that's been passed down and learned. In many cases, voice actors learn it from an engineer or a friend who's an engineer. And so they pick up these things that are like, these are the rules. And I'm usually trying to say, well, these are the rules as traditionally stated for analog recordings. we're in digital land, and I think the rules have changed. We're not even talking about 32-bit float. That's a whole... We've talked about it before. I'm sure we will again. But I mean, in 24-bit land, that's what, 144 decibels? 144 decibels of gain, yeah. There's no analog. It's beyond. Maybe they've got analog circuits that have that resolution, but you're really at the. The very, very edge of any. The digital side is not adding any noise because they don't make an analog circuit that's as clean as that digital converter. So the whole analog front end, you've just hit the... You've basically captured the sound for everything that it is. That's the way I understand it. And if you add. I'm actually sitting here looking at an LA-610 in the rack here. Yeah, I remember you had one, yeah. Yeah, it's different to the... The Apollo version, because this one's got a few other bits and bobs on there as well, like pads and. Stuff like that. Yeah, yeah. Well, this unit has a high EQ and a low EQ. Does yours have a high EQ? Yeah, and then there's like a three-position roll-off low-end, low-cut switch. You know, it does have a fair number of features. And it would have also the EQ as well. It just has high and low EQ, that's it. Yeah, because I've got peak reduction and gain on the EQ. Yeah. Do you have a compressor then? Gain reduction. Oh, that's... It's your. Yeah, the compressor. The 610's got like an LA-2A. The one on the Apollo is just emulating the preamp section only. There's no dynamics. Just the 610. Yeah. Yeah. Interesting. I know we're going off topic, but I really feel like when I pick software solutions or even gear for actors. I. Really do pick it based on usability first and sound quality second. If the sound quality is everything, then we would be all using some naive porticos or some crazy monsters. But they're so hopelessly complex. And there's just so many things. And depending on your input level, again, if you're screaming, if you're doing ASMR, those all require different gain settings to get the juice out of that circuit. Whereas if it's. Something that's extremely clean and basically wire with gain, which I like to think the Grace M101 and Millennia are designed around that. I agree. Right. The Millennia, the John Hargis, the straight wire premium proof. The Grace actually has the stepped gain and the trim, right, AP? Yeah. So do a lot of Millennias have stepped gain and trim? Right. And the step gain is nice. People may think that's annoying, but it's actually nice because it means you can very easily and repeatedly jump between two gain settings, right? So you can go click, click, click. That's my narration level. And click, click, click. That's my video game level. You know, right? Click, click, click, click, click, click. Instead of a smooth dial where you're never really, am I hitting it again? Am I hitting it? Did I nail the setting? No. And also with the dials have a broader range. They tend to get very futsy and dead spots. And you'll see something that's like a mastering version of a specific piece of equipment. All it really means is that it's got stepped attenuators that are repeatable and supposedly. Half and even a quarter of a decibel between the steps too. Yeah. Some of the really crazy stuff. Yeah. Like resistor trees. Yeah. Like, I reckon if I could only have one preamp out of the ones I've got, if I had to get rid of three, keep one, I would keep it. For your purposes, I think that makes sense. It's a workhorse. It's clean. And it's made by my friends in Lyons, Colorado. And they're my buds. So, you know, can't go wrong with that. Yeah. And they ride bikes. And they live in the mountains. And they're about to hippy-dippy watch. And they drink fat time. And we drink fat time. Exactly. Well, that was. Fun. Is it over? The Pro Audio Suite. With thanks to Tribo. And Austrian Audio. Recorded using Source Connect. Edited by Andrew Peters. And mixed by Robbo. Got your own audio issues? Justaskrobo.com. Tech support. 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 g'day, drop us a note at our website, theproaudiosuite.com.