6.Which recording device ?
- Basic concepts about recording
- Microphones and directionality
- Different solutions for different uses
- Simple recorder
- Shotgun microphone + recorder
- Parabolic dish + recorder
- Build your own microphone
- Which settings ?
There are different types of microphones that can be used for birding, depending on the way you intend to record birds.
The choice of the microphone will mainly depend on :
- What you want to record : soundscapes, individual birds, night migration ?
- How much money you are willing to spend on a microphone. You can build your own microphone for a dozen euros, or buy a super-expensive dish…
- Practical aspects : do you want to carry a big parabolic dish that will inhibit the use of binoculars, or a very handy microphone that you can keep in your pocket ? Or maybe you don’t even care about the handy aspect because you just want to put it on your roof during the night ?
- Field-proof aspects : Do you want something that can withstand rain ? Do you want to be able to record in windy conditions ?
Let’s deal with all these questions sequentially
1. Basic concepts about recording
1.1 Microphones and directionality
First of all, you have to know that all the mics do not have the same directionality. Some microphones are directional, which means that they focus on a particular direction, thus limiting the sounds coming from the sides or the rear of the microphone. This is typically the case for shotgun microphones. When pointing a shotgun microphone at a singing bird, you will focus on that particular bird. Thus, the recording of that Song thrush (Turdus philomelos) singing just in front of your microphone will be loud and clear, while you will almost not hear the voice of people talking in your back, even if they speak as loud as the Song thrush. This is very practical for sound birding as you generally want to identify or record this single bird singing in that direction.
On the contrary if you want to record global soundscapes there are some XY microphones, that basically consist in two different microphones, each recording in an opposite direction. That’s what we often call “stereo” (in opposition to “mono” = single channel recording). Such microphones will record the sounds coming from all directions at similar volumes, and hence convey a feeling of three dimensional environment while listening (you will hear that Song thrush singing louder in your right ear than your left hear, as if it really was located on your right). This is probably the best choice if you want to record soundscapes.
Classical microphones (like shotgun microphones) are composed of three parts, that are generally bought separately:
– The microphone head, that converts sound into an electronic signal.
– A powering module, that contains the battery.
– A wind protection : this is a kind of sock or bag that you put on the microphone to reduce the parasitic noise generated by the wind. You can remove it when there is no wind.
Once they are put together this gives something like that :
Microphones do not “zoom” sounds. What you record is exactly what comes to your ears (with attenuated sounds coming from the sides if you use a directional microphone).
In fact, the songs you will play on your computer will often sound clearer and louder than what you really hear in the field. This is simply because you can record sounds on the field, and then play them louder on your computer, so that the faint notes can be heard louder.
To draw a comparison with photography, this is a bit like using a digital zoom. Details appear when you look closer at the picture. This means that if the recording has a good quality (no parasite noise), you can artificially amplify a sound (see how to amplify a sound with Audacity for example) or simply put the volume of your speakers louder. If you do so, you will also amplify the parasitic noise in the background of the recording.
But there is a way to zoom directly on the sound you are recording : this is what parabolic dishes are made for. They work exactly like optical zooms on a camera : they focus more sound waves on the central microphone, so that the birds sound louder than they actually do.
Parabolic dishes produce clearer sounds but are expensive, cumbersome and so directional that you will need to wear headphones to focus on the bird you want to record.
A microphone transforms sounds into an electric signal. To save this signal as a readable computer data, you need a recorder. Most of the time a microphone is actually directly integrated within the recorder, so you can both record and save the audio file on the same device. But it is also possible to add an external microphone on the recorder.
In any case, keep in mind that the sound quality will depend on the quality of your microphone more than on the quality of your recorder.
Technically, you can now buy recorders that include fairly good microphones, so that you can record birds with one single pocket-sized item (a recorder). This can be a practical solution. At this stage, just remember that it can be worth buying a good microphone to put it on a medium quality recorder. The different options are discussed with more detail below
2.Different solutions for different uses
2.1 Simple recorder
The easiest way to record sounds is to use a digital sound recorder with a built-in microphone. You will find a big variety of recorders on the web, at different prices.
Since the microphones included on the recorders are generally made for studio-recording use, they are not as directional as shotgun microphones, and since they are smaller the quality can be affected. This solution is very practical yet because all the device can be held in a pocket.
If you’re using directly the microphone of the recorder, don’t forget to a put wind protection on it to reduce disturbance, and see the paragraph about settings to set correctly your recorder for soundbirding.
As far as I am concerned, I own an Olympus LS-12 and I am pretty happy with it (but see below)
2.2 Shotgun microphone + recorder
This is the device that I use. The idea is to improve the quality of the recording by adding a shotgun microphone to the previous device.
I personally use the Olympus LS-12 recorder (see above) and a Sennheiser ME 66 shotgun microphone. The microphone is connected to the recorder with a XLR-Mini jack cable (plug the XLR end on the powering module of your microphone, and the Mini Jack end on the “external mic” part of your recorder.
That’s how it looks like :
This solution provides clearer, more focused sound recordings. If the bird is not too far, then the recording can be really good. Check out recordings my Xeno-Canto public profile to listen at recordings taken with the Olympus LS-12 + Sennheiser ME66 combination.
Don’t forget to read the paragraph about the settings if you use this kind of device (bottom of the page)
2.3 Parabolic dish + recorder
Using a parabolic dish provides an amazing directionality. Actually it is so high that you will need to wear headphones to focus while handling a large dish . Therefore, when using a parabolic dish, don’t expect to use a scope or even binoculars at the same time.
There are two ways of getting a parabolic dish :
- Buying it (they are often very expensive. Some brands like Telinga provide all-in-one solutions for soundbirding)
- Building it yourself. ( see for example the following tutorial : https://www.videomaker.com/article/f20/17144-how-to-build-a-parabolic-mic-dish)
Note that the choice of the microphone depends on the parabolic dish.
2.4 Build your own microphone
If you have a little budget, you can build your own microphone. I’ve seen such microphones in the US and I confirm that this is indeed possible to identify migrating birds with a homemade microphone like this one :
So depending on what you want to do this can be a good solution
3.Which settings ?
If you chose this solution, don’t forget to change your settings for a specific soundbirding use.
On the microphone :
- Activate the high pass (= low-cut) filter. The high pass filter enables you to remove low-pitched background noise such as mechanical noise (city activity, cars). Since almost all bird songs are high-pitched, they won’t be affected.
On the recorder :
- Set your recorder to the highest sensitivity, you want to record faint sounds, not a metal concert !
- For the same reason, set the highest recording level.
- Put the high-pass (= low-cut) filter of your recorder too. Because two high-pass filter are better than one !
- Set the recording format to “Mono” if you are using an external directional microphone. With a shotgun microphone for instance, you don’t record in two different direction as in a XY microphone. Hence, recording in “Stereo” will record the same audio track twice. This takes two times more space on the memory without improving the sound quality. So chose a “Mono” format.
- If you use an external microphone, don’t forget to select it on the menu (This will be something like “external mic ON” or “central mic OFF”)
- Pre-recording. One interesting feature on some recorders is the pre-recording. Pre-recording enables you to start recording up to 2 seconds before you press the button for recording. So when you press the “Rec” button just after you hear this Yellow-browed warbler (Phylloscopus inornatus) call, the call will in fact already be recorded. In other words, you can record a bird that gives a single call, even if you start recording after the call. Great isn’t it ?
Read the next page of “The quick guide to soundbirding” : Softwares and audio processing