Ode to the microphone: A podcaster's selection guide

If you had to pick one item that can make the difference between night and day when it comes to recording a podcast, that item would be the microphone.  I say this while fully acknowledging that there are some podcasters that prefer night while others prefer day.  But if you're after the best possible sound you can get -- something along the lines of what professional broadcasters strive for -- then it helps to know "enough to be dangerous" when it comes to selecting microphones.  I say "microphones" with an "s" because when it comes to microphones, one size doesn't fit all. In other words, if you're like me -- a podcaster that could just as easily find himself trying to conduct an interview in a noisy bar (the way Dan Bricklin did when he interviewed production pro John Osborne) as he might find himself doing a one person show from his home office, then you should also know that different recording situations also call for different microphone types. 

Why is knowing this really important? Not because you need to go out a buy a collection of microphones that would shame your local TV station.  But rather, if you're like a lot of podcasters who are working on a limited budget that can only accommodate one good microphone, then it helps to know a thing or two about microphones (a.k.a. "mics") before deciding which one will be the one.  What follows is pretty exhaustive.  So get a cup of coffee or tea and kick back a little before taking this in.

One of the keys to deciding on a microphone is to know the lingo.  For example, the more I researched microphones and other sound gear, the more I saw the acronym "ENG."  Knowing diddly about sound or microphones, I just assumed it stood for "engineering" as in "audio engineering."  As it turns out, just the fact that "ENG" kept showing up in the places I was looking was a good thing.  That's because it stands for Electronic News Gathering and it generally applies to the category of gear that news professionals (reporters, their crews, etc.) take with them when they go "on location."  Not surprisingly, some microphones are designed specifically for ENG applications.  In other words, they're designed to deliver the best possible sound given the range of situations that news gatherers might encounter in the field.  For example, if you've ever watched TV news reporters interviewing someone on location, then you can't help but notice how they wave their microphones back and forth between themselves and their interviewees.  

Both ENG microphones as well as some vocal performance (singing) mics are designed with this sort of mic handling in mind (picture, if you will, what Mick Jagger does with a microphone when in concert).  Whereas some microphones are designed to be mounted or suspended in some sort of microphone holder, others must take into account the fact that they'll be manhandled.  To accommodate such manhandling and the noise that would normally go along with it (for example, many microphones will pick up the sound of your fingers moving on the microphone's body), certain microphones -- especially those designed for ENG and live performances -- have shock absorption systems built into them to reduce or eliminate mic handling noise.  Some microphone manufacturers such as the legendary Electrovoice have even trademarked their shock absorbing systems. 

Mic handling isn't the only source of unwanted noise.  Four other major noises that can detract from an otherwise great interview are wind, popping, echo, and background noise (like a loud crowd).   Wind is self-explanatory and chances are you've heard wind in a recording. The built-in microphones in most consumer grade video cameras will often pick up wind noise.  Or, perhaps you've heard excessive breathing into a microphone (almost as though someone is blowing into it).  In some cases, wind noise may be a desired effect.  But for most podcasts, probably not.  Popping is the noticeable pop that can be heard when the speaker uses a word that begins with the letter "P."  Try making the "P" sound without puffing some air at the same time and you'll see what I mean.  That puff of air is what causes the pop because of the way most microphones are sensitive to air.  ENG microphones are usually designed to filter out wind and popping noise.

But, when it comes to echo and background or "ambient" noise, the ability of a microphone to filter those out is less a function of the special technologies found in a microphone's capsule (the part with the grille on it) and are more a function of their directionality.  A microphone's directionality refers to where the source of a sound is relative to the microphone's capsule and the extent to which the microphone will detect that sound or not.  For example, an omnidirectional microphone will pick up sound coming from any direction.  In other words, it has a 360 degree pick-up pattern.  Depending on the manufacturer and model, most first degree unidirectional microphones -- otherwise known as cardioid microphones -- are most sensitive to sound coming from approximately 120 of those 360 degrees; in other words, it cuts the sensitivity pattern of an omnidirectional mic by two-thirds thereby yielding the directionality that cardioids are known for.  Beyond cardioid microphones are additional degrees of directionality -- hypercardioid and supercardioid. 

Here, manufacturer and model play an even greater role in the interpretation of what is meant by hypercardioid and supercardioid.  One manufacturer's hypercardioid could easily fall within the range of supercardioid according to another manufacturer.  But regardless of how directional an ENG microphone is, one of the key characteristics of a good cardioid mic is what it does with "off-axis" sound -- sound that's coming from outside it's main sensitivity range.  Is the sound muddied and garbled or is it relatively clear but just with significantly less volume or pick-up? The ability of a good directional mic to deal properly with off-axis sound is one of a cardioid mics most important jobs. Going back to Dan Bricklin's interview of John Osborne in a noisy bar, Bricklin is using a Sennheiser MD 46 (pictured above right) which streets for approximately $175, you can hear how perfectly the microphone captures the essence of the situation.  The voices of Osborne and Bricklin rise above the ambient noise.  But the ambient noise is part of the festive environment that needs to be captured as well and it can be heard with near perfect clarity as though you were standing in the bar, talking to Osborne, and hearing the background noise with your own ears.  The MD 46 is one of the finer ENG microphones on the market.  Not only does it have the shock absorbers, anti-wind, and anti-popping technologies in it, with it's entirely black finish, it's also a beautiful microphone for interviews where video is involved. 

Another area where cardioid mics come in handy is in dealing with echo.  Many of my podcast interviews have a noticeable amount of echo in them.  For example, if you listen to my interview of SpikeSource CEO Kim Polese (which took place in a hotel lobby), you can hear how her voice sounds normal while my has some echo to it.  Had I been using one microphone, then you wouldn't have heard that echo.  But, because of how long the interview was and how I wanted a consistent "level" on Kim's voice (interviewees will often back away from a handheld microphone yielding inconsistent audio results), I used two microphones.  In my hand was a Shure SM58 cardioid microphone.  But, pinned to Kim's collar was a Sony ECM 55B omnidirectional lavalier  microphone (streets for around $335).  The SM58 is famous for being the workhorse of live performances and concerts.  You've probably seen the SM58 more times than you've seen any other microphone.  It's directionality avoids picking up noise from the crowd or the sound system (which would lead to feedback), it has the shock absorbers and other technologies needed to survive the rigors of a live performance, and you can run it over with a tank and it will still keep on working (in other words, it's durable).  But its short body and silver grille are its shortcomings when it comes to ENG applications.  Longer bodies mean it's easier to reach an interviewee's mouth (picture a crowd of reporters trying to get good audio from a lawyer on the steps of a courthouse).  In TV situations, the silver grille is apparently a no-no.  For me, this is irrelevant if my interviewee is miked up with a second mic and there's no video involved.

So, where did the echo come from? The reason there's no echo in Kim's voice is because the SM58 is a cardioid microphone.  When I was holding the SM58 and she was sitting opposite me on a couch, she was technically off-axis to the mic in my hands.  The SM58 could barely "hear" her.  But her microphone, on the other hand, was an omnidirectional lav (lav is short for lavalier).  Recall that omnidirectional mics have a 360 degree pickup pattern which means that Kim's mic was picking up my voice a split second later than the SM58 in my hand.  The result? Echo.   This is where miking up multiple people becomes an art.  Based on what you've read so far, the answer you're probably thinking, if the situation definitely calls for a lav mic on the interviewee, is a cardioid lav like Sennheiser's ME 4.  But not so fast.  One reason many lav mics are omnidirectional is that they'll still pick up the interviewee's voice even if the interviewee shifts position in a way that would put them off-axis if a cardioid was involved.  Can you position a cardioid lav on someone's clothing in such a way that they can do a bit of shifting without going off axis? Probably. Is it a piece of cake? Probably not.  It's an art and good sound technicians can probably fine tune the recording levels when using omnidirectionals so as to eliminate the chances of echo. I'm still learning.

Another way to deal with the problem that I won't go into here is to use a multi-track recorder like Edirol's R4 (streets for about $1300).  Had I used a multitrack recorder when I interviewed Kim, my SM58 would have been "assigned" to one track and Kim's lav mic would have been assigned to another.  Then, in post-production, good audio editing software can "gate" tracks in such a way that one track is practically turned off when the other(s) is/are active.  So, with my voice coming in louder and clearer through the SM58, the track that Kim's microphone was assigned to is leveled-down to the point that the secondary pickup on my voice is eliminated from the final production.  It's an editing trick (one that I didn't use at the time because I had no idea what was wrong).  Technically speaking, if you're using your computer to capture a recording, it could be a two track recording since the some computer microphone jacks take stereo input.  But to take advantage of the left channel as one track and the right as another, you need a special stereo microphone.  They're out there.  I have one.

Even though it seems like cardioids have a lot going for them, that doesn't mean they're the way to go. One tell-tale sign that omnidirectionals are big in the ENG business is how the workhorse ENG microphone -- the one that more pros use than any other ENG mic -- is an omnidirectional mic. This is the Electrovoice RE50-B (pictured right) which streets for about $165.   More recently, Electrovoice has come out with a more vibrant sounding version of the RE50-B known as the Electrovoice RE50N/D-B (streets for about $185). According to Electrovoice's Web site, the RE50N/D-B has a neodymium magnet structure for higher output.  Both are omnidirectional mics with a long body.  That, along with all the sound reducing technology and their black finish, have made the RE50 the de facto standard when it comes to ENG. To understand why an omnidirectional works so well in ENG situations is to understand what the reporter is doing.  If he or she is waving a microphone back and forth or holding it towards the subject, then the reporter is not worried about it picking up his or her voice.  In fact, in some situations where you're not sure if you can get a good angle on the interviewee (like on the courthouse steps), an omnidirectional mic that can pick up the subject as well as the the questions being asked by other reporters is just what the doctor ordered. 

While I was recovering from back surgery, I couldn't sit a the computer and do a lot of typing. But I could click around and in doing so, I discovered the other ENG industry standard microphone: the Beyerdynamic M58 (no relation to the Shure SM58). Like the RE50s, the M58 has all the ENG bells and whistles (noise reduction, long handle, etc.).  It's not black.  But it's the "other" color (grey) that you see being used in interviews all the time.  Personally, I think they're ugly. But they must have something going for them because they cost the same as the higher-end Electrovoice R50.  Interestingly, unlike Sennheiser which makes both an omnidirectional ENG handheld mic (the MD 42) and a cardioid ENG handheld mic (the MD 46), Electrovoice doesn't have a cardioid newsgathering mic (it does have other cardioids, but they don't have the ENG bells and whistles).   Beyerdynamic on the other hand does have another ENG microphone -- the M59 (streets for $250) -- that's a hypercardioid (it jumps right over cardioid).  While convalescing, I picked one up on eBay for $60 and I can't wait to give it a try. 

Speaking of eBay, if you're patient and you can wait long enough to get a good deal, then it's a great way to acquire your gear.  For people like me doing daily scans for specific merchandise, it can be a bit of a chore but eBay does have a programmable search facility that will alert you when new items turn up.  The trick is to figure out how to make sure the search is narrow enough to yield just the results you're looking for, but that's broad enough so as not to exclude a potential "hit."  For example, a programmed search on "Electrovoice" will miss any listings where the seller used "Electro Voice." So, my search term is (Electrovoice,"Electro Voice").  Since I'm on the lookout for several Sennheiser microphones, my programmed search for those is simply Sennheiser microphone.  This yields more results than I really want, but writing a more specific search for all the renderings of all the Sennheiser mics that I'm interested in was more trouble than it was worth (I tried).  The one thing I wish eBay did was offer a way to mark rejected listings.  In other words, listings I never want to see in subsequent interations of my searches. 

So, what are the other Sennheiser mics I'm looking at.  Going back to Dan Bricklin's interview of John Osborne, Osborne talks about a Russian brand of microphone known as Oktava which apparently offers the sort of quality that's normally associated with very high end microphones that cost two to five times as much (as Oktava's offerings).  Upon investigating the one he spoke of -- the Oktava MK-012 -- I discovered (in true newbie fashion) that some of the higher end mics like the MK-012 are modularized in a way that the capsules  can be switched to change the microphone's properties.  For example, for the MK-012, Oktava makes interchangeable omnidirectional, cardioid, and hypercardioid capsules. Microphones with this sort of versatility have their advantages.  For example, when going on location, it might be more convenient to bring one microphone body and a few capsules rather than three separate mics.  Or, if just a capsule fails on you, you don't have to replace the entire microphone.  On the other hand, depending on the brand of microphone, the modular capsules can cost more than a complete microphone that's more than adequate for podcasting. 

But for what it's worth, one of the microphone "systems" that I've developed a fascination for is based on Senneheiser's K6 power module.  For starters, power is not something that's come up so far in this discussion. Except for the Oktava microphones I just mentioned and the Sony lavalier microphone mentioned earlier, all of the microphones I've discussed so far are dynamic microphones.  In other words, they don't require any external power to operate.  In contrast to dynamic microphones, condenser microphones (the Oktava and Sony mics qualify) require a power source. In some cases (for example with the Sony lavalier microphone), this power is delivered in-line (through the wire to the lavalier mic) by a battery.  In others, the device to which the microphone is connected (often a mixer) can deliver what's known as phantom power (often 48 volts) through the microphone cable to the microphone itself.  Although condenser mics can deliver better reproduction of sound than their dynamic counterparts, the difference is probably not appreciable enough to matter for the spoken words found on most podcasts.  Generally speaking, it's probably better for podcasters to go with dynamic microphones, just like ENG pros most often do.

That said, the Sennheiser K6 Series from Sennheiser appears to be something pretty special.  Like the Oktava's, it works with interchangeable capsules.  But in addition to offering omnidirectional (the MD 62), cardioid (the MD 64), and supercardioid (MD 65) capsules, Sennheiser also offers short-barrel (the MD 66) and long-barrel (the ME 67) capsules that work with one of two K6 powering modules.  A diagram on Sennheiser's web site shows how it all snaps together.  Why is this special.  Well, depending on what sort of podcasting you're doing, a complete K6 setup could come in handy.  I've already encountered several situations where I wished I had a shotgun mic (the equivalent of a cardioid that can zero in on a speaker that's several feet away) on hand. 

But such modularity doesn't come cheap.  Just a K6/ME66 combination (no other capsules) generally sells on eBay for $350 to $400.  Will I buy one? If I happen to luck into an extraordinary deal on eBay, maybe.  But probably not because, even though I can use a shotgun microphone, I probably wouldn't take advantage of the K6 modularity when it comes to using either the omnidirectional or cardioid capsules.  That's because the K6 capsules, like most condenser mics (which tend to be more sensitive than dynamic mics), are probably more susceptible to mic handling noise, popping, and wind than the aforementioned ENG mics that have a bunch of bells and whistles to filter out such interference.  In fact, just a sweep of K6 listings on eBay reveals that many sellers were using additional accessories such as windscreens and shock mounts to insulate the microphone from unwanted noise.  Windscreens go over the capsule and are often made of foam or a fur like substance.  Shock mounts are cleverly designed shock absorbing assemblies the suspend the microphone in a way that whatever is holding the shock mount (like a handle) can be moved around without causing excessive handling noise.

 

Circling back to the Oktavas (pictured above), they too are probably not used very often in handheld situations.  Even their bodies aren't exactly designed for a handheld application.  But, should you decide to buy a pair of Oktava MK012's for usage in your podcast studio (where they won't get moved around a lot), you'll be getting about the best sound that a couple of hundred dollars per microphone can buy.  You just need to be careful where you buy them.  OktavaUSA.com is apparently the only Oktava authorized wholesaler in the US.  If a dealer you're working with claims to be an authorized reseller, OktavaUSA can confirm it for you.  They did for me when I checked up on Red Square Audio which happens to have some outstanding prices.  For short period of time, there were some Chinese-made counterfeits available through some US retailers.  They're no longer on retail shelves, but they're still in circulation (particularly on eBay).  OktavaUSA.com has a good visual how-to on distinguishing authentic Oktava's from the counterfeits and the Oktava Web site in Russia has information as well.

Finally, a note about cables.  All of the microphones listed here use three-pronged XLR cabling (pictured left).  To most audio newbies used to dealing with stereos and computers, XLR cables will be something new to deal with.  But it's worth it when compared to the cheaper microphones using 1/4 inch or 1/8 inch (3.5 mm) jacks.  Not only do XLR cables resist the introduction of ambient electromagnetic frequencies (EMF) that can add hum to your recordings, they can deliver phantom power to condenser mics and more importantly, are very resilient to being plugged and unplugged tens, hundreds, or thousands of times.  If you've ever seen a stressed out or destroyed 3.5mm jack in the armrest of an airplane seat, that should give you some idea of why audio pros use XLR cabling. 

Not only might this requirement affect the microphones you buy, but should also influence the recording gear you go with.  What will you do, for example, when the 1/8 inch microphone jack on an iRiver recording device or on your computer decides to fall apart? That said, if you have no choice but to go with a recording device that has an 1/8 inch or 1/4 inch input, the best option is to pick one of the better XLR-based microphones and then use an adapter to convert from XLR to whatever input jack type you're using.  They key here is to know some of the specifics about the input jack.  For example, is it a mono or stereo input? Edirol's R1, for example, has a 1/8 inch stereo input jack.  It enables you to use a stereo microphone in such a way that the R1's left and right channels can technically be treated as separate tracks with separate inputs (some stereo microphones for example have cables that "Y" or separate into two distinctly different microphones: one for each channel).  If you're using an XLR-based microphone that with a stereo input jack and you want both the left and right channels to pick up the sound coming through the microphone, then the adapter must be an XLR to stereo input rather than an XLR to mono input.  This is one of the smaller, but no less important details to consider when configuring your "rig."

Anyway, for all you podcasters (new and old) out there wanting enough know-how on microphones to be dangerous, now you have it.  What follows is a listing of the marketing blurbage that some of the aforementioned microphone vendors have put on their web sites about their products.  You may find it useful.  Also shown in some cases are the prices that I was quoted by Leos Pro Audio in Oakland, CA.  Leos supplies some of the local TV outfits with their gear.  While recovering from back surgery, I did a lot of calling around on prices for the podcasting gear that I was shopping for.  While you may be able to find better prices on the microphones, in total, Leos beat everyone else on the total package I ended up buying.  As a result, I gave them my business.  If you call them, ask for Mark Haynes and tell him I sent you.

Electrovoice RE50-B ($162 Leos) Industry standard live interview microphone,  "Mic-within-a-mic" concept reduces wind and P-popping noise l Features EV DynaDamp™ shock mount l Extremely low handling noise for superior sound l Dynamic omni-directional capsule with camera friendly matte black finish.  

Kissing cousin is the Electrovoice RE50N/D-B ($186 Leos) Shock-mounted N/DYM® handheld interview microphone Same rugged design of the RE50/B with neodymium magnet structure for higher output Features EV DynaDamp™ shock mount Extremely low handling noise for superior sound Mic-within-a-mic" concept reduces wind and P-popping noise

Sennheiser MD 42 - The omnidirectional MD 42 is a high-quality reporter's microphone with omni-directional pick-up pattern. It has been specially optimised for rough use in live reporting and broadcasting environments. The MD 42 is a very 'good-natured' microphone whose design avoids wind and handling noise problems. Colour: black, sound inlet basket: refined steel, black.

Sennheiser MD 46  ($173 Leos) - The MD 46 is a high-quality reporter's microphone with cardioid pick-up pattern. It has been specially optimised for rough use in live reporting and broadcasting environments. The MD 46 is a very 'good-natured' microphone whose design avoids wind and handling noise problems. Colour: black, sound inlet basket: refined steel, black.

Beyerdynamic M 58 ($186 Leos) omnidirectional -- The M 58 has been specifically designed to satisfy the demands of Electric News Gathering (ENG) and Electronic Field Production (EFP) applications. Its sophisticated internal shockmount dramatically reduces handling noise, while the microphone’s frequency response has been tailored to provide broadcasters with a very accurate and intelligible sound. The M 58’s weight-balanced design provides journalists with a high degree of comfort during lengthy interviews. Its rugged construction enables the microphone to withstand physical and environmental punishment typically encountered during field production operations. The M 58’s slim profile and non-glare finish result in a low profile on camera.

Beyerdynamic M 59 ($247 Leos) hypercardiod - The M 59 is a rugged, vocal quality dynamic microphone employing enhanced-field magnet technology designed to withstand the critical demands of in-studio or on-location ENG/EFP speech and interview applications. The microphone’s low mass, large diaphragm Macrolon element and hypercardioid polar pattern provides very fast transient response, high output, high sensitivity, with startlingly accurate reproduction of the sound source while also providing excellent off-axis rejection. Each M 59 incorporates a sophisticated internal shock-mount isolation system designed to reduce stand, boom, or handheld noise and vibration.  Its durable construction and non-glare finish will provide consistent protection against the rigors of on-air and on-location ENG/EFP production applications. The M 59 also encorporates an internal multistage blast filter designed to reduce undesirable wind or pop noise. An optional WS 59 large cell wind screen is also available and recommended for on-air, voice-over and other close talking applications. The M 59 is designed to meet the critical demands of studio on-the-air or studio voice-overs while also meeting the rigors of on-location ENG/EFP news. Due to its high gain-before-feedback the M 59 is ideal for lecterns or miking of wind instruments. The M 59 can be used on a stand, boom, gooseneck, or as a handheld microphone.

Shure SM 58 ($188 MSRP) The legendary Shure vocal mic is tuned to accentuate the warmth and clarity of lead and back-up vocals. Consistently the first choice of performers around the globe. The Shure SM58® is a unidirectional (cardioid) dynamic vocal microphone designed for professional vocal use in live performance, sound reinforcement, and studio recording. A highly effective, built-in, spherical filter minimizes wind and breath "pop" noise. A cardioid pickup pattern isolates the main sound source while minimizing unwanted background noise. The SM58 has a tailored vocal response for a sound which is a world standard. Rugged construction, a proven shock mount system, and a steel mesh grille ensure that even with rough handling, the SM58 will perform consistently. Outdoors or indoors, singing, speech - the SM58 is the overwhelming choice of professionals.

• Frequency response tailored for vocals, with brightened midrange and bass rolloff
• Uniform cardioid pickup pattern isolates the main sound source and minimizes background noise
• Pneumatic shock-mount system cuts down handling noise
• Effective, built-in spherical wind and pop filter

Shure SM 48 ($144 MSRP) - Shure Models SM48 and SM48S unidirectional dynamic microphones are designed for professional sound reinforcement, studio recording, and broadcasting applications. They maintain a true cardioid pattern throughout their frequency range, ensuring high gain before feedback and rejection of off-axis sound. The tailored frequency response is ideal for vocals. A presence rise brightens mid-range performance, and a low frequency rolloff controls proximity effect.

Both models include a shock mounted cartridge, a steel mesh grille, and an integral "pop" filter. The SM48S also includes a lockable On/Off switch.

• Cardioid pickup pattern rejects off-axis sound and provides superior gain before feedback
• Frequency response tailored for vocals, with brightened mid-range and bass rolloff to control proximity effect
• Shock-mounted cartridge for exceptional ruggedness and reduced handling noise
• Built-in "pop" filter that reduces explosive breath sounds and wind noise

Shure SM 86  ($300 MSRP) The Shure SM86 is a unidirectional (cardioid) condenser vocal microphone for professional use in live performance. An extremely rugged microphone, the SM86 withstands the rigors of touring while delivering studio-quality sound. The tailored frequency response of the SM86 reproduces vocals with clarity. A cardioid pickup pattern isolates the main sound source while minimizing unwanted background noise. The built-in three-point shock mount minimizes handling noise, and a two-stage pop filter reduces wind and breath "pop" noise. The SM86 is an excellent selection for use with both stage monitors and personal in-ear monitors.

• Condenser cartridge for studio quality sound
• Tailored frequency response for a clear reproduction of vocals
• Rugged construction withstands the rigors of touring sound
• Cardioid polar pattern minimizes unwanted background noise
• Excellent choice for stage monitors and personal in-ear monitors
• Built-in three-point shock mount minimizes handling noise
• Two-stage "pop" filter reduces wind and breath noise

Be sure to look for the next installments of my series on podcasting gear.  In them, I'll discuss portable recording devices, mixers, and how I involve "callers" into my podcasts by "seizing" the phone line or using a VoIP solution like Skype.