How to record the ocarina

Whether you want to record yourself to share, to study your playing, or you're an audio engineer tasked with recording an ocarina player, here are some tips for getting a good sound. Audio engineers should skim the first section as it includes notes on good microphone types for ocarinas.

Microphones and speakers

The majority of microphones in smart-phones and laptops are designed to capture a legible human voice, not musical instruments. If you want to make a decent sounding recording you need a microphone designed for this purpose. Basically, you have 3 options dynamic microphones, condenser microphones (Linked to Wikipedia) and portable audio recorders.

Portable recorder,
zoom h1
USB condenser microphone, AT2020

The simplest option are portable recorders. They are all-in-one devices with built-in microphones which record onto an SD card. Using one is just a matter of pressing the record button. Being simple, they are a great option to get started and are useful for recording on the go, but they are less flexible than a separate microphone and interface (next paragraph). Look for one designed for recording music and avoid voice recorders (Dictaphones). The Zoom h1 sounds very good for the cost. If you are just aiming to study your playing this will be fine.

Using a dynamic or condenser microphone, on the other hand, is more complicated. They require a computer to record and most need an XLR audio interface, though there are a number which connect to USB directly. Recording is done using software called a digital audio workstation (DAW). Audio interfaces often come with bundled software but, failing that, Audacity works for basic things and is free. I like Reaper, which isn't expensive for home use.

The main difference between dynamic and condenser microphones is their sensitivity:

Dynamic microphones are less sensitive; you have to be close to them to pick up a usable volume. This is a good thing in a typical home environment, as they reject background noise well. The SM57 is quite affordable (£100~), though be sure to avoid counterfeits.

Condenser microphones are more sensitive, which is a double edged sword: it lets you place the microphone farther away but means they pick up room sounds. Because of this, they work best in a quiet, acoustically treated space. Condenser microphones are technically more complicated than dynamics, so expect to pay more for a good one. The cheapest condenser microphones often have notable background hiss. Also note that XLR condenser microphones require an interface with phantom power; USB models are powered by USB.

Microphones also have varying frequency response and pick up patterns.

Frequency response

Humans can hear from about 20hz to 20,000 Hz and microphones rarely pick up this full range equally. How a given model behaves can be found in its frequency response graph. The X axis spans 20hz to 20,000 Hz and the Y axis represents how the microphone handles that frequency. The following graph shows a hypothetical 'perfect' microphone which captures all frequencies equally.

In practice, microphones are never perfect; they deviate for both stylistic and technical reasons. Dynamic microphones have trouble with higher frequencies which can give them a 'vialed' sound. Condenser microphones do not have this limitation.

A lot of microphones emphasize the high frequencies similar to the chart below as doing so gives many instruments a more 'spacious' sound. Unfortunately, when used to record ocarinas, this makes wind noise more obvious. Preferably, you want a microphone with a flat high end. Another option is to slightly cut this range with an equalizer.

Pick up patterns

Microphones come in different pick-up patterns which describe whether they pick up sound from all directions (omnidirectional) or a limited angle (directional). For musical instruments,you want a directional microphone to avoid capturing room sounds. There are multiple types of directional microphones including Cardioid microphones, which capture sound from about 180 degrees, to shotgun microphones that have a very narrow angle of sensitivity.

Omnidirectional
Directional

A microphone pick up pattern is visualized as a radial line graph. The center of this graph represents zero sensitivity and the outermost ring 100% sensitivity. To read this graph you start at the center and draw a line outwards in the desired direction until you hit the red line. An omnidirectional microphone is equally sensitive in all directions, thus it's graph is a circle at 100%. Cardioid microphones have a heart shaped lobe extending forwards from the center, they are very sensitive from the front and much less so from the back.

Omnidirectional
Cardioid

Do note that the red line represents sensitivity only, not absolute distance in physical space. The distance that a microphone will pick up from depends on multiple factors including background noise and acoustics.

Closing notes on microphones, plus speakers and headphones

Portable recorders, dynamic and condenser microphones can all capture a good sound from the ocarina:

  • Portable recorders are a good way to get started as they are very easy to use
  • Stand-alone microphones offer more flexibility at the cost of complexity
  • USB microphones are fairly easy to set up but choice is more limited than XLR

One option is to get a higher end portable recorder like the zoom H5; it has XLR connections and can function as an audio interface. Listen to some sound samples of microphones to get an idea how they sound. If possible, find a microphone with a flat frequency response to avoid exaggerating wind noise.

Always get the best microphone you can afford. If you are experimenting and are unsure that you will continue in the future, still get the best microphone you can afford. It should be easy to re-sell and they usually retain their value well.

Finally, a note on speakers. Like a recording made with a bad microphone will sound bad, listening to a good recording on bad speakers will sound bad. In particular, small built-in speakers tend to distort when faced with the ocarina's pure tone. This can be misleading, making you think you have a bad recording when you don't. I recommend getting some headphones as they are cheaper relative to their quality and are not influenced by room acoustics.

Microphone placement

While it may be intuitive to place the microphone in front of the ocarina in line with the voicing, this usually isn't the best option. Ocarinas. like all acoustic instruments. do not project their sound equally in all directions. Assuming you want to get a 'pure' tone, positioning the microphone above the ocarina is a better option as the body shields the wind noise. Needless to say, you absolutely have to get a microphone stand.

As microphone placement has a direct impact on tone, I recommend doing your own experiments. If you have never heard an ocarina from the perspective of an observer, get someone else to play your instrument. You may be surprised how different it sounds.

If you do wish to place a microphone in front of the voicing you will need a wind screen. Putting a microphone in the air stream is essentially the same as blowing on the microphone. A wind screen diffuses the stream.

Acoustic treatment

Within a typical home environment, there is little to dampen the reflection of sound waves. Hard surfaces reflect sound which will echo around the room, creating an effect called 'comb filtering'. Comb filtering changes the perceived volume of a sound depending on its pitch and your location. You may observe it first-hand if you move within your room playing a single note. In some places, it will sound louder than it does in others. If you instead play in an open outdoor environment, these volume spikes will be gone.

The following image shows the volume of different notes of an octave of an ocarina's range. Notice how the volume changes arbitrarily: starting from the left, notes 2 and 4 are very quiet, and note 7 has a large volume jump over note 6. This is caused by comb filtering.

Obviously you don't want these irregularities in your recordings, so what can you do about it? You have to use acoustic treatment to reduce reflections. Acoustic treatment is a soft material that absorbs and diffuses sound waves entering it, greatly reducing the volume of reflected sounds.

No treatment,
most sound is reflected
With treatment(yellow),
much less sound is reflected

Effective acoustic treatment does not need to involve expensive acoustic foam. It may be improvised using heavy curtains, blankets or bed quilts. Layering towels in frames or using fiberglass acoustic insulation are also options. Another option is to play into a walk in closet, the clothes are great at damping reflections.

Treating a whole room requires a lot of material and thus can be expensive, but it's not necessary. It is adequate to create a 'booth' within a room using floor stands. Acoustic treatment doesn't need to span the full height of the room, either; a meter above and below the level you're playing at is adequate.

In a corner, place acoustic treatment:

  • In front of you to dampen the main source of reflections.
  • Behind you to stop it reflecting back into the microphone.
  • To your left or right. The open side should be against a wall. Usually, you want a 'live' wall as it brightens the sound.
  • If you do not have a carpet, using a fluffy rug or putting acoustic treatment on the ceiling will also help.

This is how it would look, the arrow indicates direction you would play in.

Even very basic acoustic treatment can dramatically improve the balance of a recording. The following was achieved just by placing couch cushions in front of and behind me, and hanging a bed quilt on the right. It isn't perfect and there is still a drop out, probably because I have a hard floor, but it's still much more listenable. This was recorded with the same microphone in the same location, using the same settings. The only difference is the acoustic treatment.

Before

After

Don't bother with curved 'reflection filters'. These attempt to absorb sound before it bounces off the wall in front of you. However, they are not big or thick enough to do this effectively. Note that they do little to stop sound entering the rear of a microphone as cardioid microphones already do this well.

so note that this acoustic treatment is not soundproofing. If there are other noises like people talking or a road, you will hear them in your final recording. You should aim to eliminate these at the source by recording when nobody is around, turning off air conditioners, and choosing a location as far from a road as is practical.

Recording

How you go about recording depends on whether you are using a portable recorder or a microphone with a computer.

Portable recorders: Take a look at your devices user manual for basic usage. Normally, it's good enough to just press record. Note that many of these recorders have auto-gain, which adjusts the volume of the recording automatically. If your recorder has this feature, disable it as it will eliminate your instruments volume dynamics. Set the gain manually as described below.

Microphone and computer: Connect your microphone to your audio interface or USB if it's a USB microphone. Check that your software is recording from the USB microphone or audio interface, not the built-in microphone. Normally, this can be set in your DAW's options. Read a 'getting started' guide for your DAW for more. Your software will have a microphone level meter which will look similar to the images under 'setting gain' below. If you tap the mic or speak into it, you should see the level meter change.

Setting gain (applies to both)

Digital recording can only represent sounds up to a limited volume; if a sound is too loud, it will 'clip', which sounds terrible. Your recorder, be it a portable recorder or a DAW, will have a gain meter (see below). Play through your tune as if you were going to record it and watch the gain meter. You should set the gain on your microphone so the meter hits about 80%; it should never max out.

Pictures left to right. 1: too low, 2: about right, 3: clipping.

Exactly how to set the gain depends on your device or software. Portable recorders often have buttons to set gain. XLR audio interfaces and some USB microphones have a gain knob. Many USB microphones set this in software through your computer's audio settings.

Making some recordings

Now you are about ready to make some recordings. Set up your microphone as described above. Make sure you point the correct part of the microphone at your instrument. Dynamic mics normally work 'end on' but condensers often pick up from the side. With that set try making some recordings.

The temperature of your recording space should not change greatly during your session as the ocarina's pitch is temperature sensitive. If you play in an environment notably colder than your ocarina was tuned for and compensate by blowing harder, you will not get the best sound. The harder you blow, the more airy and harsh an ocarina will sound. It is preferable to either heat the room or play flat and re-tune your accompaniment. If something must be in concert pitch, you can correct this afterwards. All good digital audio workstations can slightly raise or lower the pitch of a recording without changing the speed or quality.

Post processing

Once you have a recording, there are a number of things you can do to improve the sound: for example, dynamic range compression and equalization. Note that compression in this context has nothing to do with reducing the size of the stored file like an mp3.

Ocarinas are considerably louder on their high notes than their low notes and dynamic range compression can be used to bring them into balance. Effectively, it is an automatic volume knob that turns down sounds louder than a threshold. I recommend looking for tutorials on how to do this in your DAW as the details are beyond the scope of this page.

Equalization provides a means of modifying the loudness of different frequency ranges of your recording. When recording ocarinas this is mostly used to remove low-frequency rumble and to compensate for microphones that boost high frequencies. You can freely cut low frequencies as ocarinas don't produce any sound below their fundamental, about 520Hz for an alto C (Equal temperament note frequencies). How you apply this depends on the software you are using.

Summary

  • Always get the best microphone you can afford.
  • Portable recorders, dynamic and condenser microphones can capture a good sound from an ocarina.
  • Position the microphone above the ocarina to get the cleanest sound; the body shades wind noise.
  • Positioning the microphone farther away will also reduce wind noise.
  • Microphones that boost high frequencies will exaggerate wind noise, so look for one with a flat response or cut this range with an equalizer.
  • Acoustic treatment is essential as ocarinas are sensitive to comb filtering.
  • The temperature of your recording space should be constant as an ocarina's pitch is temperature sensitive.
Exercises

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