This episode was written and produced by Andrew Anderson.

Since their founding almost a century ago, Shure has created some of the most iconic microphones ever made. In this episode, we worked with Shure to tell the story of the SM7 dynamic microphone: from its humble beginnings in voiceover studios in the early 70s, to its use on classic albums, to its rediscovery by podcasters and streamers.

MUSIC FEATURED IN THIS EPISODE

Organized Chaos by Arthur Benson
Snooty Fox by Ritchie Everett
Thief by Rossier
Hot Stuff Goin On by The Best Ofs
Clogged Up by Jerry Lacy
From Stardust by Christoffer Moe Ditlevsen
The Face of the Thrush by Migration
Chafftop by Muffuletta
Funk and Flash by Calumet
Don't Wanna Be Dead Anymore (Instrumental) by Coma Svensson
Glide (Instrumental) by Ehiorobo

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If you know what this week's mystery sound is, tell us at mystery.20k.org.

View Transcript ▶︎

You’re listening to Twenty Thousand Hertz.

[music in]

The topic for this episode is one that is near and dear to my heart. Actually, it’s really near to my face right now... in fact, it’s the closest thing to me right now: this microphone [sfx: taps the microphone], which is a Shure SM7.

Every single episode of Twenty Thousand Hertz has been recorded with this exact same microphone. But it’s not just me. Tons of musicians, and podcasters, and streamers all use an SM7... I would go as far as to say that this might be the most prolific and important microphone of the last two decades.

Surprisingly though, this mic has actually been around a lot longer than that. The story of the Shure SM7 starts more than 80 years ago with a game-changing invention, and ends with some of the most famous & influential creators alive today.

In order to get the story right, we worked with Shure on this episode. They helped us with research, fact checking, and also provided financial support. We had full editorial control, and crafted this episode just like any other one. So, let’s start from the beginning...

[sfx: rewind effect into radio static + music in]

Michael: Shure was founded in 1925 by S.N. Shure, Sidney Natkin Shure, but he preferred S.N. He was 23 years old.

This is Michael Petterson, Shure’s official historian.

Michael: Shure was a radio parts company [sfx: sound of old radio tuning]. AM radio was all the rage and you actually had to build your own radio back then. Mr. Shure was a radio hobbyist. He said, "I'm going to create a catalog company where people can mail in their orders in and Shure will provide the parts to make the radios."

Business was good, so Shure decided to partner with a local company that made microphones. That deal fell through after a few years, but Shure stayed in the microphone business.

Michael: By 1932 we were actually manufacturing and designing our own microphones.

For Shure, it was a case of being in the right place at the right time.

Michael: You have to realize, in the early '30s there was a big change going on and things that we take for granted now we're new back then. Two-way radio like for police, fire emergency was new. Public address systems were relatively new. Radio stations, they were growing dramatically and recording studios were changing from being acoustic recordings into electrical recordings. All those things required microphones. Mr. Shure saw a need.

[music out]

But it wasn’t until Shure hired a recent college graduate that business really started booming. That person was Ben Bauer, and he changed the way sound was recorded forever.

Michael: If Ben Bauer hadn't come to Shure, I'm not sure we would be in business these days. This guy was a genius. There's no doubt about it.

[music in]

Bauer was a great engineer—shy, but super productive.

Michael: This guy created a new invention nearly every day.

Over the span of his career, he was awarded more than 100 patents, including one for an underwater microphone, and another for a quadraphonic sound system, where music was split into four channels… rather than two.

Michael: He would go to work at Shure [sfx: car], come home [sfx: door open/close], have dinner with the family [sfx: cutlery], do a little work after dinner [sfx: hammering/tinkering], sleep for four hours, get up at 1:00 in the morning [sfx: alarm clock] [night sounds] and work through the rest of the night [sfx: hammering/tinkering].

Michael: I think he just had so many ideas, he couldn't get them out quick enough.

[music out]

When Bauer arrived at Shure, the big problem was making microphones smaller. Up until then, every microphone needed at least two capsules, which are kinda like the motors that make them work. Bauer’s goal was to find a way to get a great sounding mic with just one capsule.

Michael: At age 24, he came up with the idea of what's called the uniphase acoustical network. That's the acoustical network inside of a microphone that allows it to be directional.

A directional mic captures sound coming from just one or two directions, blocking out other unwanted sounds. They’re great for recording vocals.

Michael: And that allowed us to come out with the first Shure Unidyne Microphone, the Elvis Microphone sometimes people call it.

[music in]

It’s called the Elvis mic because it’s the one you see The King using in all those famous photos from the fifties. It’s the mic that looks kinda like a radiator grill on a classic car. And, If you type “microphone tattoo” into Google, you’ll see this microphone is super popular as body art. But the Unidyne didn’t just look cool: it also sounded great, and more importantly; it was small enough that it could fit on a mic stand.

[music out]

The Unidyne microphone was so groundbreaking that the Institute of Electrical and Electronics Engineers, the I-triple-E, gave it one of their milestone awards. It’s basically like the engineering equivalent of an Oscar.

Michael: They go to people and ideas and things that changed the world. For example, the creation of stereo sound [sfx: quick pan of Michael], the breaking of the Enigma code [sfx: enigma sounds], the Apollo 11 Program [sfx: rocket taking off], the work of Nikola Tesla [sfx: electricity].

Michael: IEEE, felt that the Unidyne Microphone has changed history so much that it deserved a milestone award. For us, that's a really huge honor to have.

The Unidyne microphone was smaller than the mics that came before it, but it was still pretty big. So the next thing Ben Bauer did was make a smaller version, the Unidyne Two, which came out in the early 50s. Because it was smaller, it didn’t block people’s faces when they were singing on television.

Here’s a clip of Little Richard using it on a TV broadcast in 1956.

[SFX Clip: Little Richard on TV]

Soon enough, singers everywhere started asking for a microphone that they could hold in their hand.

[music in]

Michael: Singers like Jerry Lee Lewis, Chuck Berry, Elvis, they wanted to grab the microphone and move around. And the Unidynes are just a little too big for that, so we started bringing out the Unidyne III which is what's called an endfire microphone. You speak into the end of it rather than to the side of it and it’s easy to hold in your hand.

The Unidyne Three isn’t a specific microphone model like the 1 and 2. It’s actually a microphone capsule that Shure still uses in its most famous models. For instance, it’s in the SM58, which is that classic handheld microphone with the pop filter ball on top… It’s basically the mic that you picture in your head when you think of someone singing on stage. This capsule is also found in the the SM57 which looks like the standard singing mic, but without the ball on top ...and finally, that Unidyne Three capsule is inside my microphone, the SM7. The “SM” in these names simply stands for “studio microphone.”

Michael: The Unidyne III is what we refer to as the motor. It's the insides of the microphone, and then you can put different bodies around those motors, kinda like cars, in a way.

The Unidyne Three capsule was developed by Ben Bauer’s successor, Ernie Seeler.

Michael: Ernie was a mathematician extraordinaire, spoke excellent English with a German accent and was one of these people that you could probably not even look twice at if you didn't know he was a genius.

Michael: Ernie's first microphone was the Unidyne III, talk about starting at the peak of your career.

[music out]

The Unidyne Three capsule’s impact was huge. It was used by the Beatles on their US tours [sfx: screaming].

Some people have gone as far as saying that without the Unidyne Three capsule, modern rock concerts might not even be possible. Before this mic came out, it was really easy to get feedback like this.

[sfx: “Testing 1, 2.” tap tap tap “Is this thing on?” + feedback]

The Unidyne Three was the first mic capsule that let you turn up the volume really loud before you get any of that nasty feedback. This was great news for rock bands – although not everyone was happy about it.

Michael: Ernie was not a fan of rock and roll and I think always irked him that this microphone that he brought out became popular for music that he really despised.

Michael: You’d say "Hey, Ernie, did you see the Rolling Stones are using your microphone?" You'd get, "Mmm." That's about it.

Although Shure had some great stage mics, they didn’t really have a microphone for voiceover work. They had another microphone called the SM5, which sounded good, but it weighed over two pounds, and was as big as a football.

Michael: The SM5 wasn't very successful. A lot of people were saying, "It's kind of big. It's kind of expensive. It doesn't give us enough output level”.

Michael: We decided to make a smaller, less expensive voiceover microphone. We took the insides, the Unidyne III element, out of the SM5 and we put that inside the SM7. And in 1972, the SM7 was ready to go.

[music in]

John: The SM7 is a wonderful microphone.

This is John Born from Shure. John is responsible for guaranteeing that every SM7 sounds exactly right.

John: The SM7 is a dynamic mic.

The three most common types of microphones are a dynamic, a ribbon, and a condenser. Mechanically, dynamic microphones are the simplest.

John: A dynamic mic works just like a speaker works.

John: A speaker, for instance, you can send energy into that system and play back audio. And a microphone works the same way in reverse.

John: As we talk, we emit energy into the air, acoustic energy, and we use a system of a diaphragm, a coil attached to that diaphragm, surrounded by a magnet.

John: As that energy hits that diaphragm and moves that coil within that magnetic field, that gets converted to electrical energy.

That electrical signal travels [sfx] through the microphone cable and into whatever you’re recording with. Most microphones that you see on stage are dynamic mics.

John: Dynamic microphones are a much less sensitive system. They have a lower output and they are far less sensitive in high frequencies.

This is why dynamic mics are so great for recording vocals: because they do a better job of cutting out the other sounds in your environment. Condenser mics are also really popular for vocals, but they do have some drawbacks.

John: Condensers are more sensitive you're going to get more room reflections on a condenser. [sfx: room noises / reflections] They pick up lower frequencies and higher frequencies at the extremes much better than a dynamic microphone can.

[music out]

As intended, the SM7 was smaller than the SM5, and it was perfect for recording a voice. Part of what makes it work so well is actually due to the limitations of dynamic mics.

Originally, Ernie Seeler wanted the SM7 to have a flat EQ response. That means it would respond the same to all frequencies, from bass sounds [sfx: bass boost in VO, bass guitar] to the high-pitch frequencies [sfx: treble boost in VO, guitar].

John: As an engineer, I can see why he would want the broadest single, he would want the flattest single. He'd want the most honest and linear signal that he can get.

John: Now, doing that on a dynamic microphone is really hard. It's very, very hard to make a dynamic microphone's frequency response flat. The team spent a very, very long time trying to acoustically make the SM7 flat.

John: But at some point, the team said, "You know, this is as good as this flat response is going to be”.

The SM7 doesn’t have a completely flat response – it actually emphasises frequencies in the two thousand hertz to seven thousand hertz range [sfx: 2000h-7000h tone]. Fortunately though, this lines up with the sibilance range of the human voice. Sibilant sounds are sounds like “ssss”, “zzzz”, and “shhhh” – those types of sounds make speech easy to understand.

For example, if we cut out this range while I’m speaking [sfx], it becomes a lot harder to understand.

John: Because of that, it just becomes a really, really popular choice for voice.

But Ernie Seeler still wanted that flat response as an option. So he put a couple of switches on the back of the SM7: one that cuts out the really low frequencies, and one that flattens out the presence response.

Here at Twenty Thousand Hertz, we EQ my voice in post production, but for these examples, we’re going to take away all of that processing so you can really hear what these switches do.  Here’s what I sound like with the normal processing we do taken away. I also turned both of the switches on the back of my microphone off.

[sfx: switch click]

Now, here’s what the microphone sounds like when I turn on the low-cut switch. It takes away most of those low, thumpy sounds, especially when you bump the mic.

[sfx: tap mic]

[sfx: switch click]

And here’s what I sound like with the presence peak. Notice how it makes my voice more crisp and clear.

John: It's a really great tool to have because sometimes you do want that bite, whether that's a guitar amp or a very dark voice that you want to brighten up. Having those response switches in the back is a nice thing.

[music in]

The SM7 might have been a great piece of design, but when it launched waaaay back in 1972, its sales were… underwhelming.

Michael: It didn't sell great. It didn't sell bad like a player in a baseball team that hits a lot of singles. You're satisfied with him, but it was never a big seller for us.

The first customers were voice over studios and radio stations. Famous radio DJ Wolfman Jack was an early adopter of the SM7.

[music out]

[SFX Clip: Wolfman Jack: I want you to lay your hand on the radio baby, we’re gonna play you’re record now...Aaaawoooo!]

But unlike Shure’s stage mics, the SM Seven was being used behind the scenes. So it wasn’t getting nearly as much exposure.

Michael: With the voiceover artists you never see what they're using. Many times, they're secretive about what they use as well because what do they do? They make their life off of their voice, right?

Michael: They may not want you to know what their techniques are, what microphones they are using.

Soon enough, musicians started to experiment with it.

[Music clip: Rolling Stones - Start Me Up clip]

Michael: Many of Mick Jagger's vocals are on SM7s. They have been dual recording Mick Jagger's vocals with a condenser mic and an SM7 since the mid-'70s and then they would listen back during the final mix and try the condenser mic and then try the SM7 and see which one they like better. So, many of the tracks that you hear Mick on are SM7s.

Chris Kimsey was the engineer and producer behind a lot of those Rolling Stones recordings. He says the SM7 is a perfect fit for singers who like to get close to the microphone. This is from an interview that Chris did with Shure a few years ago.

Chris Kimsey: I tell all singers that I work with, the SM7, you can eat it. You can get that close to it. The SM7 is so friendly, you can literally put it right up against your mouth and you can really use it. It’s fun to work with. It takes like the studio recording bit out of the equation. It’s just a direct connection between the voice and the recording path.

And it wasn’t just used for vocals. David Bowie and George Harisson started using the SM7 to mic their guitar cabinets. But it wasn’t until studio engineer Bruce Swedien decided to try out the SM7 on Michael Jackson that the mic really got some attention. Here’s Bruce in an interview with Hal Leonard Publishing.

Bruce Swedien: The sound of Michael Jackon’s vocals was very very important to me. When I recorded Michael on the SM7 I decided immediately that I don’t want anything in the way of that sound.

[Music clip: Billie Jean]

Michael: It turned out that Michael Jackson's voice and the SM7 just went really, really well together. Thriller, which is still one of the biggest selling albums ever, was all done with SM7s.

Over the years, the SM7 has been used in tons of hit songs.

Michael: There were a lot of people that were using it. It was really considered a little bit of a secret weapon in the recording studios.

The SM7 was on “Give It Away,” by the Red Hot Chili Peppers.

[Music clip: Give It Away]

Cheryl Crow used it in, “My Favourite Mistake.”

[Music clip: my favourite mistake]

Maroon Five used it on “This Love.”

[Music clip: This Love]

And Childish Gambino used it on “L.E.S.”

[Music clip: L.E.S.]

For a long time, the SM7 was mostly only known by audio engineers, and through the 90s, sales were still pretty low. Shure even considered discontinuing the mic on more than one occasion. Then, in 2007, they started to notice something strange. A mic that had sold about the same amount every year since 1972, suddenly started flying off the shelves.

[music in]

Michael: Around 2007-2008 podcasters started to tell each other about this microphone. That's when it really started to take off.

These days, thousands of podcasts use the SM7. These include 99% Invisible, Joe Rogan, My Favorite Murder, WTF, Snap Judgement, Song Exploder, Renegades, and the list goes on and on.

Michael: So here's a microphone that basically sat and idled for 35 years and then took off and it’s just doing more business now than you can possibly imagine. Can you imagine Apple holding on to a product for 35 years and then waiting for it to take off?

After the podcasters, came the streamers.

Michael: Around 2014-2015 gamers started to get SM7s.

Here’s a clip of Shroud, one of the world’s most popular streamers, using an SM7.

[SFX clip: Shroud Clip] So like, what makes a good play is the level of play, and also the skill of players in that current situation, right?

John: The SM7 is great at not only isolating yourself in the room, but also isolating the sounds off-axis that may come into that microphone.

John: You don’t hear your room tone or keyboard clicking or things off-axis.

[sfx: typing sounds]

John: That's why dynamic microphones like the SM7 are so beloved on voice because you can dig right into it and get a really rich voice without getting a lot of the extraneous noise.

On top of that, since the SM7 is bigger than most other dynamic mics, it also picks up a lot of bass– [sfx: shockjock rock: “Don’t Wanna Be Dead Anymore”]

Perfect for capturing that deep radio announcer’s voice [sfx: deep radio announcer voice].

While the popularity of the SM7 has skyrocketed, amazingly, the tech is still pretty much the same as it was back in the 70s.

John: It is identical to the way it was in the early '70s when we first came out with it.

Now, Shure has made a couple of minor changes over the years. In the 90s they added a larger humbucking coil to stop it humming when the mic is near monitors – that was called the SM7A. And then in 2001, they started selling it with a larger windshield – that’s the SM7B, which is the model I have here. [tap tap tap]

John: If we do part changes even as simple as a new knob or a new wire, we go through a really arduous detailed process on validating that, that performance of that product did not change at all.

That philosophy of rigorously testing every component dates all the way back to Shure’s founder, SN Shure.

[music in From Stardust]

Michael: Mr. Shure put his family name on the company, right? He didn't call it Microphones Incorporated or something like that. He was very specific about, "Anything that we bring out, I want it to be reliable. I want it to be durable. I want it to honor my family name."

After almost fifty years, the SM7 is a piece of recording history. It’s one of the iconic products that musicians and podcasters can recognise just by its distinctive silhouette. And it’s also helped create history.

Michael: You can go back, and if you look at almost any major event in the 20th century, now the 21st century, there's a microphone there. They weren't all SM7s, of course, but many, many times, there were Shure microphones there.

Michael: The “I Have a Dream” speech with Martin Luther King, there’s a Shure Microphone there.

[SFX clip: I have a dream speech] Free at last, free at last, thank god almighty we are free at last.

Michael: “Dewey Defeats Truman,” where Truman's holding up the Chicago Tribune with the wrong headlines, there's a Shure Microphone there.

[SFX clip Truman victory speech: I can’t tell you how very much I appreciate this turnout to celebrate a victory.]

Michael: I even worked with NASA on some of the first microphones that went into space with the space shuttle.

[SFX clip: NASA comms chat:] Houston Discovery, thanks for those words CJ. It was a great mission. We enjoyed it. We enjoyed working with you and all the teams in mission control.

Technology might be lightyears ahead of where it was fifty years ago, but physics and acoustics haven’t changed, so this microphone has stood the test of time.

John: We struck lightning on the SM7. We struck the right balance and we had that product ready when podcasting struck.

John: It just took podcasts to finally give the respect that this microphone deserves.

John: Everyone knew that this was a gem in the industry, and we just needed a new industry to find, and we did.

[music out]

[music in]

Twenty Thousand Hertz is hosted by me, Dallas Taylor, and produced out of the sound design studios of Defacto Sound. Find out more at defactosound.com.

This episode was written and produced by Andrew Anderson and Casey Emmerling with help from Sam Schneble. It was sound edited by Soren Begin. It was sound designed and mixed by Colin Devarney.

Thanks to Shure for all of their help on this episode, and thanks to our guests, Michael Pettersen and John Born.

Thanks for listening.

[music out]