Published in "Wildlife Sound" - journal of the Wildlife Sound Recording Society, vol 8, no 3.
Mr. Margoschis has been very kind to comment on one of our Telingas - the PRO III model. To this he has connected our Stereo DATmic. Let me first give a simple information: The PRO III model is now replaced by the PRO 5. The microphone connection is improved and - to allow long cables - the output impedance is lowered to 200 Ohms.
People often think that Telinga is a stereo parabola. But this is only because the Stereo DATmic is the most popular microphone. We have mono microphones, omni-directional and directional, and they all fit the PRO series. We also make the Telinga "Universal" - a handle, dish and a "zeppelin" for all stick microphones 15 - 25 mm, - like the Sennheiser.
A Telinga parabolic microphone should preferably weigh less than 2 lbs. complete - ready to use, including the dish. This means that the battery and two metal XLR plugs on the output cable is 25% of the total weight! Everything necessary shall be integrated into one unit.
The Telinga mono designs are quite conventional. Not much to say. To the Stereo DATmic we could use microphone capsules which sound "softer" and more "correct", but they all make too much noise. There are not even expensive ones to use in a stereo design. We have made some interesting experiments with M/S configurations, but weight, hand- and wind noise, not to speak about price - make such a design unrealistic. But now over to the question:
Parabolas and stereo sound? I see two questions here: 1/ Is stereo obtainable at all with a parabola, and - if so - 2/ does the Telinga performs such a result?
The first question is easy to answer: In a theoretical paper published by Journal of Audio Engineering Society, - "The Parabolic Reflector as an Acoustical Amplifier" Vol. 33, No 6, 1985 - the author Sten Wahlström concludes: " It is even possible to adopt a reflector for stereophonic recordings by a simple method .... (fig) ... The shield separates the front into two sides and will thus create a stereo background when the sound is picked up by the two separate microphones. The sound source in the center of the sound picture will be equally amplified by the reflector to the microphones....."
But - to the second question: Does the Telinga perform such stereo, as described by Wahlström? Yes - the design connects directly to the principal he describes.
The plate separates the two sides from each other, while the focused sound will affect the two microphones equally.
The focused bird will be recorded mono, while the background will be recorded stereo.
| Click here and listen to a mp3 file illustrating this. |
The stereo separation depends on the size and characteristics of the separating shield and the distance between the shield and the microphones. For practical reasons, and wind noise reasons, we want to keep the shield as small as possible. Because the microphone elements are very close to the shield - only 1 mm - the shield is still big enough to create a stereophonic "space" of the background sound picture, which disappears completely if the channels are shorted, or if one uses one channel only.
Traditionally, there has been a tendency to judge a recording as "good" if it is "clean". A recording of a Robin in London traffic, has not been looked upon as "a recording of a Robin in London traffic" - but as a poor recording of a Robin, destroyed by traffic noise.
When telephoto lenses became available for the common man, "everybody" should make pictures of birds, as if they were taken in a studio. If he did not, it only proved that he "couldn't afford buying a telephoto lens".
Today, I claim, we tend to look for other qualities, both in photography and sound recording.
I do not claim that stereo sound is "better" than mono or that using a cardioid is better than using an omni directional. I don't claim that a microphone should be facing inwards or outwards. Telinga has a system - mono, stereo, omni- directional or whatever.
Of course I advice people, but I can only do so if they give me a fair picture of what it is they want to achieve. I have no "standard recipe" for wildlife recordings.
A researcher records the information he needs for his analysis equipment. A wildlife film-maker make recordings fit to the pictures. A commercial bird-song CD producer wants to make recordings which people buy. Some ornithologists want to document what they hear, and couldn't care less about "sound quality".
Today, I claim, the tendency among wildlife recordists in general, is to make "quality" recordings of "a piece of wildlife," - not only of a bird or a special animal. It seems as if we have produced enough of "clean" recordings, and that the challenge nowadays is somewhere else. A "good" recording today is a stereo recording not only of the tiger, but also of the all around present echoes of his roar in the jungle and the sounds of his paws in the grass, or his teeth tearing up his prey.
If you download a recording of a tiger on Internet, it will not arouse your scientifical curiosity of what a tiger sounds like. Instead it will trigger your fantasy and imagination and make you shiver with thrill. The world is asking for emotions.
I once said, that "mono sound triggers your sonograms, while stereo sound triggers your fantasy." It is not all together wrong.
I have often observed that people smile when they hear a nice stereo recording of a bird in headphones. I can’t explain this smile, but I always smile too.
When you make your excursion, a warm and sunny morning, just feeling fine after a good breakfast, listening to this beautiful blackcap singing in his tree, - you don't bother much about the distant traffic noise or the noise from the wind in the leaves. You might not even notice it.
The reason for this easiness in your attitude, is that the blackcap is singing in one direction, with it's own stereo picture - while the noise is coming from "all over", with it's own - and very different! - stereo picture. Since even long before we were hunters and gatherers, we have developed this skill - to separate an important signal from unimportant noise. This is a totally unconscious process, just as our heart beats. But to do so, we need our stereophonic hearing. Everyone busy with sound recording, has noticed that a stereo recording from a noisy pub, still makes it possible for a listener to hear what people say, while the same recording in mono, easily becomes a mess of unreadable voices!
This is not a question of technical quality. It is a question of what happens when technical quality meets the human perception. We cannot concentrate on a particular voice, unless we have at least some kind of direction and/or stereo picture to guide us.
When we replay a blackcap mono recording in our living room, no such information is present. On the mono recording, the blackcap "sings" also the traffic noise and the noise from the wind in the leaves. Or - vice versa - the traffic noise and the wind noise is "singing" blackcap song! It’s the same! This is a fact, not a matter of opinion.
If somebody wants to claim that there also are other qualities than stereo which can guide us to split signal from noise, he is right. But theese qualities are also present in a stereo recording.
After this extremely depressing description of the fatal errors with mono - how come it works? Or doesn't it?
To be provocative, I claim it doesn’t! Most people listening to mono recordings which include a background ambience think they are ugly! "It is a pity with all the noise!?" they say. Cross your heart: Isn't that why we always want to exclude the background? Because in mono, almost any background sounds ugly?
I admit there are exceptions. But how many?
By far, - I claim - the most common "solution" to the mono-problem, is that the recordist doesn't record! Most of the times when wind or traffic noise is present, the traditional mono recordist leaves his equipment at home. "It won't be good anyway....." Mono recordings need ideal circumstances, and - as everybody know - such circumstances are rare nowadays.
Making stereo recordings means a truly significant simplification of this problem. Notice carefully, that I do not say that a stereo recording has less errors! But I say that it does NOT have the typical mono-problem that a signal and a background will become "the same". Even if a stereo effect is poor, even really poor, even really distorted! - there will be a difference between the background and the soloist, and this difference will help the human perception to use it's selective skills.
The typical "Telinga-sound" as it comes from a DAT recorder often sound a bit "hard". This is a consequence of our efforts to keep the inherent noise down as much as ever possible. It is not difficult to equalize a bit and "soften up" the sound, but then you get more inherent noise instead.
Telinga is now developing a variable filter to use in post production of a DATrecording. It softens up the sound a bit by equalizing, and also by limiting the dynamics a little.