Parabolic Reflectors

When thinking about my experiences when first taking up the interest in wildlife sound recording, one of the most rewarding moments was when I first pointed a parabolic reflector  with that cheap old microphone installed, at a mixed flock of Jackdaw and Rook on that cool, clear Gloucestershire morning.

The sound I heard was just thrilling. It brought nature so close to me I found it really overpowering.  In fact you could say I actually ruined the recording by uttering expletives every now and then. Nothing rude, just WOW and WOW and OH MY GOODNESS and JUST LISTEN TO THAT!!!!!

Having mentioned this to my many recording friends, most agreed that their first parabolic recording was a moment when the joy of wildlife recording really struck home. A very important moment that made them all wanting to do more.

My first parabolic reflector was sourced from a member of the WSRS (Wildlife Sound Recording Society), who actually made them for other members.  It was called an Atherstone reflector after the town where it was made.  I am still using it every now and then, just to prove it is a great reflector. A decade or so later another member took over the production, and it was renamed the Amberwood reflector.  It had a few modifications which made it even better, and that is one one I use now if I resort to having to use a reflector.
Unfortunately production of this reflector has now ceased.  It ceased over 10 years ago, when the mould used eventually became unusable. These reflectors were formed using fibreglass, and were of good rigid construction, holding their shape, , very well, most important. Mine have travelled all over the world, safely packed in a suitcase, purposely bought  to accommodate the 22 inch diameter reflector.  They take up very little space and act as a protector to my socks and underwear!!!

These reflectors were made with the purpose of using any microphone you had available. The microphone holder could be used for nearly every microphone you could imagine.  This meant that the microphones used for other purposes such as individual open mic work could be slipped into the holder, adjusted to the focus point of the reflector, covered with a windshield and away you went.

I feel I should explain myself a bit better here, after I may have given anybody listening to this that I use a reflector as a last resort, because I don't.

The benefit of a reflector is that it gives a major advantage over open microphones.  It acts as a noiseless acoustic amplifier. If the reflector dish was say 3 feet in diameter the amplification would be around 10db. I have one this big but it is impossible to carry around so I use it as a stationary reflector for Nocmig (Nocturnal migration) recording where the birds flying above are at quite a height and the more amplification I get the better.

The ones I have talked about previously are 22 inches in diameter and they give roughly 5db of amplification which is fantastic if the subject is in canopy of a rain forest or the like.

The downsides of parabolic reflector recording are at least twofold.

Firstly this amplification and noiselessness only relates to a subject that is on the axis of the reflector. This “on axis” should be imagined as a very narrow beam and if the subject moves or the recordist isn't accurate with his/her directionality, the tonal quality will change for the worst, it will sound different.

This can be difficult if the subject is moving around in the tree or in a group of birds. I, therefore only tend to use a parabola when recording an isolated subject, one that is stationary.

Secondly, a parabola of this handleable size will not be able to deal with frequencies below 1kHz.  The sound wave associated with these low frequencies is larger than the diameter of the reflector so it cannot “capture” them.  So any animal that makes a sound that is below that frequency or has a part of their sound below that frequency, will not be captured accurately by  a parabolic reflector. To capture these frequencies would would probably need a reflector approaching 6 feet in diameter. They would be tad difficult to carry about!!

Having said all that a parabolic reflector can enable the recordist to record from a safe distance without risk of disturbance. Choosing a suitable subject though is paramount. Owl or Elephant recordings for instance.

Unfortunately production of this reflector has now ceased.  It ceased over 10 years ago, when the mould used eventually became unusable. These reflectors were formed using fibreglass, and were of good rigid construction, holding their shape, , very well, most important. Mine have travelled all over the world, safely packed in a suitcase, purposely bought  to accommodate the 22 inch diameter reflector.  They take up very little space and act as a protector to my socks and underwear!!!

These reflectors were made with the purpose of using any microphone you had available. The microphone holder could be used for nearly every microphone you could imagine.  This meant that the microphones used for other purposes such as individual open mic work could be slipped into the holder, adjusted to the focus point of the reflector, covered with a windshield and away you went.

If I search the internet today, there are a few limited basic parabolic reflectors available. Anybody wanting to adapt their previously bought microphones for reflector use will be disappointed. (If anybody reading this knows of a supply, please let me know). 

What there is instead are two firms that can supply the whole parabolic reflector kit. Parabola, with all handles, mic support, windshield etc. complete with microphone and necessary cabling. These firms are Wildtronics in the USA and Telinga in Sweden. Telinga have stockists throughout the world while I cannot find the same for Wildtronics.

Both these manufacturers use their own designed microphones, which are of adequate quality but are not the best quality microphones available. Having said that, most people would not notice the difference, particularly taking into account the inherent problems associated with parabolic reflectors.

One of these manufacturers, Wildtronics, do a kit for using your own microphone in place of theirs. This is, in my opinion, very sensible of them and I congratulate them on their flexibility. I do believe that Telinga used to provide something similar but it seems not to be offered any more.

To conclude, anybody wanting to start wildlife sound recording should first find someone who is already doing it (see joining a wildlife sound recording group). Ask to borrow their reflector and point it to the natural history sound of your choice. If you are not blown away by what you hear through your headphones, then perhaps, wildlife sound recording is not for you.

If, on the other hand, you, like me and many others are amazed by what you can hear, then get yourself some kit, and get out there, and start having immense fun, capturing the sounds of nature.

I wish you all the luck in the world.

RB 22/11/19