Recommending a Mic

A friend recently asked me for a unique mic recommendation – unique here in the U.S. anyway – he wants a really nice mic for recording mbira. There’s not much online discussion about mbira recording, and music tech marketing is all about “vintage” and “killer vocal mics,” but less-familiar instruments are still worth considering!

Wondering what an mbira is?

With my rock ‘n roll frame of reference, the mbira’s sound is reminiscent of electro-mechanical pianos, like the Fender Rhodes or Wurlitzer 140, but its plucked reeds and rattles add a more human character. It’s probably most appropriate to call the mbira a “folk” or “traditional” instrument, but it also finds its way into popular music – here’s an example that broke the mold 10 years ago (mbira at 1:20).

Recording has lots of conventional wisdom, but how do you approach an instrument without a standardized recording technique? One answer is: it’s art, it’s subjective, approach recording however you want! Which is fair, find your own sound and all that. But, if you’re being critical and not simply experimenting, you should recognize that you’ll work faster and/or achieve a better result if you actually understand what you’re doing.

My friend Ben, who asked for the recommendation, is an experienced percussionist who performs and records professionally. Prior to Covid he was touring with the pit orchestra for a musical; lately he’s been spending more time with softer instruments, like mbira.

As we talked, Ben raved about the tone from a recording we did 8 years ago, and wanted to know which mic I had used. Unfortunately for him, it was an expensive one.

The mbira in that song was tracked in an isolation booth, with a Wunder Audio CM7 FET. That was the first NICE mic that I bought, shortly before that session in fact, and I still use it all the time. If I were going to record a solo mbira performance right now, I would reach for that mic or something similar.

Mic Basics

Conventional mic technology comes in 3 flavors: Condenser, Dynamic, and Ribbon.

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An assortment of mics (photo by Lynae Cook)

With tonally-rich, low-volume instruments, like mbira, a condenser mic is the natural choice. The CM7 FET mentioned above is one of many condenser designs.

Dynamic mics tend to be durable and can sound great, but don’t capture detail as well as ribbons or condensers. Ribbons will pickup fine detail, but require a big signal boost with quiet instruments (also boosting static and hum).

For a percussionist, the versatile option is to own a small-diaphragm condenser mic (or a stereo pair). These “pencil” mics record high frequencies well, and tend to have a neutral sound. They’re arguably the best choice to record many percussive instruments, but mbira?

If I were going to record an ensemble, as is common in traditional mbira arrangements, I’d probably want a stereo pair of small diaphragm condensers. However, Ben made clear in our conversation that he wants to record the mbira as a solo or feature instrument, which means the mic needs to enhance the sound of the instrument – the same consideration made when recording a lead vocal. Large-diaphragm condenser mics are good at this.

Getting Technical

So you found a mic review that describes “silky” mids, “euphonic” highs, or something vague like that. How does that correlate with what’s actually going on inside a mic?

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Someone’s mic (from pintrest).

The Capsule
The circular gold thing in the photo above is the capsule – it’s the part of the mic that turns sound into electricity, and it shapes the tonality of a mic. The capsule is an electrical and mechanical component, requiring precise manufacturing, so you get what you pay for.

The CM7 FET has a K47/49-style capsule, which is a design that has been in continuous production since the 1950’s. It has great low-mid response (sounds full), a boost in the mid-range (helps voices and solo instruments stand out), and a slight cut at the highest frequencies (mellows out harsh sounds). I find these capsules to be similar in tone to many dynamic mics, just more detailed.

The Circuit
In all condenser mics, there is an amplifier following the capsule. The amplifier in the CM7 FET is a design from the mid 1970’s – the early days of solid state (post-tube) electronics. Some complain that this circuit sounds “harsh,” which I think is true when compared to older tube mics or newer designs with cleaner amps. Loud vocals, drums, and guitar amps can distort sensitive mics, highlighting that audible harshness, but mbiras never get that loud.

Durability
Great vintage mics sound good, but they’re still in use because they were built to last. It’s a huge mistake to consider only the sound of a mic, because a mic’s lifespan is shortened by pinching pennies on the metalwork, shock mount, case, switches & knobs, cable & power supply, etc. Many budget and “boutique” companies do this. Watch out for rattling metal, peeling paint, loose parts, etc.

Making a Recommendation

For Ben, I recommended two expensive mics from two of the oldest mic companies still operating, Neumann and Microtech Gefell. In fact, they were the same company prior to the cold war division of Germany; Gefell is the East German offshoot that stayed independent after reunification.

The Neumann TLM 49 and the Gefell MT 71 S are two current production mics that look extremely different, but sound very similar. The TLM49 uses the K47/49 capsule, the one that’s been in production since the 1950’s. The MT 71 S capsule is based on an even older design, the predecessor to the K47/49 capsule, created when the two companies were one. Both mics have extremely clean amplifiers and aren’t likely bug anyone with “harshness.”

Both mics retail for over $1,000, and that’s what it costs for a mic of the highest quality. Ben is an experienced professional musician who will be performing and recording for years to come, so owning an expensive mic makes sense.

The upshot is that the good stuff holds its value, but the best is not always accessible…

Other Options

Other large-diaphragm condenser mics with similar tone are available for hundreds less. Look to companies like Mojave and Peluso for good sound with cheaper (but not crap) construction. For recording mbira, I’d reach for any mic with a K47/49-styled capsule.

If ruggedness or price point is your concern, dynamic mics are where it’s at. A condenser will capture more detail, but top-quality dynamic mics sound great, will come close on detail, and can be much more affordable. The Sennheiser MD421 and Electro-Voice RE20 are both studio mainstays that can be thrown across a room without breaking, and are under $500 new. Even THE NICEST dynamic mic available, the Sennheiser 441, is reasonably priced by fancy-mic standards.

A small-diaphragm condenser would be my choice if an artist requested a “clean” sound for almost anything, including mbira. Small-diaphragm condensers are also about half the price of large-diaphragm designs, for comparable quality. The Josephson C42 would be a great choice for mbira at around $500.

As always, weigh your options and do you best to avoid buying junk. If I had $200, I’d buy a used Sennheiser MD421 over a budget condenser.

If any audio engineers from Zimbabwe (home of he mbira), find this and want to set me straight, I’m all ears! I’d love to hear about your approach.