Best Microphones For Miking Marimba


The marimba is a tuned percussion instrument with a very unique sound. Marimbas are tuned chromatically, like a piano, giving the marimbist access to all the notes of western music theory. The bars, resonators, and rubber mallets of the marimba yield deep tones with a relatively rich harmonic profile (compared to other tuned percussion instruments).

When recording the marimba, the microphone (transducer) is an important piece of the signal flow. Mics also provide an effective way to reinforce or amplify the marimba in live situations. So which microphones suit the marimba best? Here are my recommendations:

  • Neumann U 87 AI: The Neumann U 87 AI (link to check the price on Amazon) is a multi-pattern large diaphragm condenser mic that gets the top recommendation for miking marimba. A pair of U 87 AI’s, though expensive, will efficiently capture the sound of a marimba in nearly any situations and in many common microphones positions.
  • Electro-Voice RE20: The Electro-Voice RE20 (link to check the price on Amazon) is a large diaphragm cardioid dynamic microphone that exhibits no proximity effect. The RE20 is the top recommendation for close-miking marimba and for miking the resonators of the instrument.

Before we discuss each of the recommended microphones, let’s get to know the sound of the marimba a bit better:


Disclaimer:

“Best” is a dangerous word. There is really no such thing as a “best microphone” for any situation. The microphone(s) listed in my Recommended Microphones And Accessories” page are simply my recommendations. These recommendations are based on my own experience and are mindful of budget. It would be easy to suggest an ELA M 251 or U47 for most scenarios. However, these tube mics are very expensive, putting them out of a hobbyist’s price range and making it difficult for professionals to make their money back on the gear.

Another important note is that the microphone or equipment you choose is not the most important part of recording audio. In fact, there are many factors that are arguably more important than the choice of microphone. These include:

  • Performer (whether a musician, speaker, or otherwise)
  • Instrument
  • Microphone technique/placement
  • Number of microphones used
  • Natural sound of the room
  • Content (whether that’s the song, discussion, or otherwise)
  • Signal chain (including mic cable, preamplifier, console, and/or interface/computer)

With that being said, some microphones and gear suit some instruments better than others, prompting this series of articles under “Recommended Microphones And Accessories.”


What Does A Marimba Sound Like?

When choosing a microphone for any application, it’s to our great advantage to know the characteristics of the sound source. So what does a marimba sound like?

The marimba is made of chromatically tuned wooden bars. Each bar is a different size and is isolated from its neighbouring bars by strings and pegs. This allows each bar to hang and vibrate freely. Each bar also has its own resonator tube (located underneath the bar), which amplifies the sound of the fundamental and softens the tone of the marimba.

The unique sound of the marimba comes from the way the bars are tuned. The fundamental, 4th harmonic (two octaves up) and 10th harmonic (three octaves plus a major third) are the three prominent partials of the marimba sound.

Softer mallets dampen the higher partials, creating a darker sound, while harder mallets excite the higher partials, creating a brighter sound.

A Note On Miking The Marimba

The marimba is quite a large instrument up close (roughly 8 feet or 2.5 meters long). Therefore, close-miking the instrument with a single microphone is not ideal. If we are to use a single microphone, I’d suggest the U87AI in omnidirectional mode positioned about 8 feet from the instrument in order to capture the full sound of the marimba.

Two common miking techniques for the marimba include a spaced pair 4-8 feet from each end of the marimba (adjust distance to taste) or an X-Y pair positioned some distance away from the centre of the marimba. Large diaphragm condensers work well for these techniques. Omnidirectional mics work best for spaced pair while cardioids work best for X-Y (the Neumann U87AI offers both of these options.

When close-miking the marimba (often for isolation reasons), we’ll often have to choose to mic the resonators or the keys. Furthermore, we’ll have to pick a smaller region to accentuate when close-miking the marimba due to its size. The RE20 makes a great choice if we need to close-mic since it’s cardioid, have a reasonably flat frequency response, and does not exhibit the proximity effect.

For more information on microphone placement, check out my article Top 23 Tips For Better Microphone Placement.

Frequency Range Of Marimba (4-Octave)

  • Overall Range: 131 Hz ~ 15,000 Hz
  • Fundamentals range: 131 Hz – 2,093 Hz (C3-C7)
  • Harmonics range: 524 Hz ~ 15,000 Hz
  • Important harmonics: 4th and 10th harmonics

So we want a microphone that will accurately capture the true sound of the marimba. Knowing the fundamental frequencies and the harmonics of the marimba is a great place to start. On top of this, there are a few more criteria to keep in mind when choosing the best marimba microphone.


What Makes An Ideal Marimba Microphone?

There’s really no such things as an ideal marimba microphone since there are so many ways of miking a marimba. No one size fits all, but let’s talk about some key points that would make for a great marimba mic here:

  • Versatility: There are countless ways to mic a marimba. This is due to the size of the instrument, the rooms the instrument would find itself in, and the mechanics that go into producing the marimba sound (bars on top, resonators on bottom). Choose a microphone that works well with the many marimba miking techniques.
  • Flat/extended frequency response: Choose a microphone with a flat frequency response to accurately capture the interesting sound of a marimba. The marimba has a wide range from C3-C7 (131 Hz – 2093 Hz) and a distinctive harmonic profile that extends upwards of 15,000 Hz.
  • Sensitivity: A sensitive microphone will record more subtleties in the marimba performance than a less sensitive mic. Sensitivity also applies to the strength of the mic signal, which is an important value to consider when recording quiet marimba passages or when miking the marimba at a distance.
  • Accurate transient response: It’s always preferable to have a pronounced transient response when miking percussion instruments. Percussion instruments, generally speaking, have the strongest transient information that should be captured accurately. The marimba is no exception.
  • Low self-noise: Large diaphragm condenser microphones are usually considered the best bet for miking marimba. These mics are active and therefore have self-noise. Choosing a quieter active microphone will help to further capture the subtle nuances in the sound of a marimba and better reproduce the quiet moments of a marimbist’s performance.
  • Directionality: Select a directional microphone to better suit the miking technique you’ll be using to record the marimba.

Let’s now discuss the recommended marimba microphones according to the above criteria:


The Neumann U87AI

Neumann U87AI

The Neumann U87AI microphone is modelled after the legendary vintage U87. The AI model sounds slightly brighter and “hifi” while the original U87 sounds slightly darker and “vintage.”

The Neumann U87s are multi-pattern large diaphragm condenser microphones. They are recommended as marimba microphones due to their great versatility, wide frequency response, and accurate diaphragms.

These microphones are both excellent choices on marimba. I’ll discuss the U87AI here since it is currently in production, whereas the original U87 is not.

Versatility Of The Neumann U87AI

The Neumann U87AI has various settings to choose from. The U87AI can play a role in any of the common microphone arrays or positions used when miking a marimba. Let’s quickly run through the switchable options of the Neumann U87:

3 Selectable Polar Patterns

  • Omnidirectional
  • Cardioid
  • Bidirectional (Figure-8)

For more information on microphone polar patterns, check out my article The Complete Guide To Microphone Polar Patterns.

1 Selectable High-Pass Filters

  • No HPF
  • 3 dB/octave HPF @ 1000 Hz

For more information on microphone high-pass filters, check out my article What Is A Microphone High-Pass Filter And Why Use One?

1 Selectable Passive-Attenuation-Device (PAD)

  • Default
  • -10 dB Pad

For more information on passive attenuation devices, check out my article What Is A Microphone Attenuation Pad And What Does It Do?

Having all the above options available in the U87 makes it an ideal microphone for many of the marimba miking techniques.

Frequency Response Of The Neumann U87AI

The frequency response of the Neumann U87 is listed as 20 Hz – 20,000 Hz. Here is the frequency response graph of the U87 in omnidirectional mode:

Image from Neumann U87 Specification Sheet

As we can see, the Neumann U87AI has an incredibly flat frequency response from roughly 60 Hz to 5,000 Hz. This range encompasses all the fundamental frequencies of the marimba and some of the important harmonic content as well. And so the Neumann U87AI is exceptionally accurate at capturing and reproducing the character and music of the marimba.

The U87AI exhibits a noticeable boost in its upper frequency response. This helps to accentuate the upper frequencies of the marimba. An enrichment of these frequencies helps to enhance the character of the marimba (especially the sound of the mallets hitting the bars).

Another important note is that at the very upper range of the U87AI frequency response there is actually a fairly steep roll-off. The roll-off help to reduce the chances for an overly bright and harsh sound. This is critical in the days of digital recording, where the high-end is often over emphasized.

Note that one of the biggest differences between the U87AI and the vintage U87 is that the newer AI edition sounds slightly brighter than the original.

The high-pass filter of the U87AI is designed mostly to counteract the proximity effect when used in close-miking situations. If we are to use the U87 in a close-mic array on a marimba, try engaging the HPF and listen to which version of the signal sounds best to you. That being said, the U87AI sounds best at a distance from the marimba, so there’s likely no need to engage its HPF.

For more information on microphone frequency response, check out my article Complete Guide To Microphone Frequency Response (With Mic Examples).

Sensitivity Of The Neumann U87AI

The sensitivity ratings of the U87AI vary depending on the selected polar pattern:

  • 20 mV/Pa in omnidirectional mode.
  • 28 mV/Pa in cardioid mode.
  • 22 mV/Pa in bidirectional mode.

These are typical ranges for a condenser microphone. The U87AI will output a usable signal even when capturing the marimba from a distance.

For more information on microphone sensitivity, check out my article What Is Microphone Sensitivity? An In-Depth Description.

Let’s talk about a couple of specs that are related to microphone “sensitivity,” including transient response and self-noise.

Transient Response Of The Neumann U87AI

There’s no explicit measurement for a transient response specification, but if there was, the U87AI would get a great rating. The light-weight large diaphragms of the U87AI are very reactive to changing sound pressure levels, giving the microphone an accurate transient response. This helps to capture a true, accurate sound of each bar that is struck on the marimba.

Self-Noise Of The Neumann U87AI

Electronics are needed in order to have multiple settings within one mic and because the Neumann U87AI is an active “true” condenser. These electronics inherently produce some noise, which is known as a microphone’s self-noise. The self-noise ratings of the Neumann U87AI depend on the selected polar pattern:

  • 15 dBA in omnidirectional mode.
  • 12 dBA in cardioid mode.
  • 14 dBA in bidirectional mode.

The U87AI is by no means the quietest microphone on the market, but it’s definitely quiet enough to not deprive a marimba performance of its beauty.

The self-noise of the U87AI would barely be noticeable unless the marimba was set up in a soundproof room. This scenario is only sometimes the case.

For more information on microphone self-noise, check out my article What Is Microphone Self-Noise? (Equivalent Noise Level).

Directionality Of The Neumann U87AI

A common microphone choice for recording the natural sound of the marimba is an omnidirectional mic. The U87AI omnidirectional pattern graph is shown below:

I chose to show you the graph the coincides with the omnidirectional mode polar pattern since it’s a common pattern for marimba studio recordings. That being said, please experiment with the 2 other patterns the U87AI has to offer. You can check out the other graphs in the specification shee here.

As we can see here, the U87AI does become more directional (bidirectional to be specific) at higher frequencies in the omnidirectional mode. This is typical of omnidirectional microphones. When using the U87AI in omni mode, I’d still suggest pointing the microphone at the marimba for the best capture of the high-end frequencies.

For more information on the omnidirectional microphone polar pattern, check out my article What Is An Omnidirectional Microphone? (Polar Pattern + Mic Examples).

But this is just the omnidirectional mode. The cardioid and bidrectional modes of the U87AI are also excellent choices depending on microphone placement technique around the marimba.


The Electro-Voice RE20

Electro-Voice RE20

The Electro-Voice RE20 is one of my all-time favourite dynamic microphones. It has a light-weight diaphragm that reacts very well to changing sound pressure levels and exhibits no proximity effect even though it’s a cardioid microphone.

I’d recommend this microphone for close-miking the marimba. The microphone sounds great on the bars of the marimba and even better on the resonators.

Versatility Of The Electro-Voice RE20

The Electro-Voice is not versatile like the Neumann U87AI. However, it does have a high-pass filter that gives it a bit of flexibility.

The arguable versatility of the RE20 comes from its Variable-D technology, which removes any proximity effect from the microphone. That’s right, the RE20 is a cardioid microphone that does not exhibit the proximity effect. This means that there will be no bass boost as the mic gets closer to the marimba, allowing arguably better results from more microphone positions.

Frequency Response Of The Electro-Voice RE20

The RE20 is rated as having a frequency response between 45 Hz and 18,000 Hz. Here is the frequency response graph:

Image from the Electro-Voice RE20 Specification Sheet

Note that the frequency response graph of the RE20 also shows us what it picks up at 180-degrees (the opposite direction of where the microphone is pointing).

The flat response of the RE20 in the low-mids and low frequencies makes it an excellent choice for recording the marimba. The low-end roll-off happens below the marimba’s frequency range, allowing the microphone to accurately capture the sound of the marimba while filtering out some of the low-end rumble that may be present.

The high-frequency roll-off helps somewhat to warm up the sound of the marimba in live and studio settings. This is useful when close-miking the marimba since the striking of the bars with harder mallets produces transients that are quite harsh.

Sensitivity Of The Electro-Voice RE20

The RE20 has a sensitivity rating of 1.5 mV/Pa. This is low, but not out-of-the-ordinary for a dynamic microphone. The low output of the RE20 requires a quality preamp to boost its signal to workable levels.

The low sensitivity of the Electro-Voice RE20 is one of the reasons why the mic is best used in close-miking situations.

Transient Response Of The Electro-Voice RE20

The RE20 is exceptionally reactive to sound pressure relative to other moving-coil dynamic microphones. The performance of the RE20 is due to its large Acoustalloy diaphragm in combination with an exceptionally low-mass aluminum voice coil.

This reactivity to sound waves makes the RE20 an excellent choice in capturing the nuanced transient information innate in the marimba’s sound.

Self-Noise Of The Electro-Voice RE20

The Electro-Voice RE20 is a passive dynamic microphone with no self-noise.

Directionality Of The Electro-Voice RE20

The RE20 is a cardioid microphone with the following polar pattern diagram:

Image from the Electro-Voice RE20 Specification Sheet

As we can see from the graph, the RE20 does a great job at rejecting sound from 120-degrees to 240-degrees off-axis across its entire frequency response. The RE20 has roughly 16-18 dB rejection at 180-degrees.

The RE20 doesn’t have a great amount of off-axis colouration, which helps to maintain the sound of the marimba that comes into the microphone at an angle (remember how big a marimba is).

Speaking of colouration, the RE20 also does not exhibit any proximity effect, even though it’s a cardioid mic. This is because of its Variable-D technology. What this means is that there will not be an excessive bass boost as the marimba gets closer to the microphone. This makes it an excellent choice in live settings where the rule of mic placement seems to be “closer the better.”

More importantly in live situations, this cardioid pattern allows for placement in front of monitors with smaller risk of microphone feedback.

Once again, close-miking isn’t necessarily the best way to mic a marimba. However, when it does become the best option, the RE20 should be a go-to microphone.


The Recap

So these are my top two recommended microphones for capturing the sound of a marimba. Of course, there are many microphones that sound amazing on marimba, and this is strictly my opinion. Hopefully you’ve picked up some info that will help you decide on what microphone will work best for you when recording marimba.

To wrap things up, I’ll recap the two recommendations here:

  • Neumann U87AI: Best sounding and most versatile large diaphragm condenser mic on marimba.
  • Electro-Voice RE20: Best dynamic microphone for close-miking marimba.

Honourable mentions:

  • Telefunken U47
  • AKG C414
  • Warm Audio WA-251

For all the My New Microphone mic/gear recommendations, please check out my page Recommended Microphones And Accessories.

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