Telinga "Stereo DAT" mic page 2

In November 2005 I visited a wood to check on owl activity. There were a lot around! This short sample of a fight between two tawnies was recorded from a bridge over a stream . The winner was a male I had heard ranging freely around, sometimes accompanied by his wife. Other owl pairs or males in the area were more static. The owl he attacks and chases off sounds like a youngster -- possibly a “floater”, a young owl that has not established a territory. The change in acoustics in the middle happens because the attacking owl flew directly above to reach his rival. So initially the dish is facing a distant road and then swings 180° to where the two owls fought briefly, and fiercely, in branches above the stream. Quite a screech this one. Telinga with dish.

Tawny scrap 1 Mb

Next one is actually from the same recording, happening a minute or so later. It’s only included as these alarmed pheasants make rather a fascinating noise -- quite scary at night. Was it a reaction to the owl, the same dominant owl, heard just before they start up? I wondered, but more likely there was a fox around. I’ve not heard of tawnies attacking pheasants, though we have seen one flying over a pen in which pheasant young were being bred. Telinga with dish.

Pheasant cacophony 540 kb

Back to previous page

More comments on the Telinga Stereo DAT mic

Here is Klas Strandberg's Telinga site. Klas makes the kit. He does several types, including conventional mono dish mics. Mine is the Stereo DAT mic used with the PRO 6 handle, which is the one for mics taking phantom power. The 22" dish is a separate item. What's unique about this setup is the use of a stereo mic in a dish. On one page there's a useful discussion about how the microphone produces stereo sound, and why this is a desirable feature if the ear is to pick up one sound and reject other, unwanted sound.

Basically, the capsules in the mic are placed either side of a plastic shield (you can just see this circular disk in the photo on my introductory page). Focused sounds from a source directly in front of the dish (i.e. along the central axis) are recorded in mono, but off-centre sounds are picked up more strongly by one side or other of the mic, giving the stereo effect. I also suspect that a lot of sound reaches the capsules directly, with no reflection, including sound that passes through the back of the dish, adding to the sense of ambience but also to the tendency to pick up noise from the rear. Elsewhere Klas recommends turning the dish very slightly away from a singing bird to reduce the mono effect and add subtlety to a recording. It's a good tip. With a bird dead centre the sound can whack into both ears equally, giving a rather flat effect. Turn the dish ever so slightly away and you still get the focused sound, but a stereo effect starts kicking in and a more subtle and pleasant recording can be made.

There's another reason such good, atmospheric recordings can be made with this parabolic mic setup. Many bird calls and songs depend on echo for their full effect. In a wood this echo comes from surrounding trees and their hard trunks, and one suspects that some birds make use of small-scale topographic features to enhance their singing. Near us a favourite singing area is in the trees around a pond set in a deep bowl like an amphitheatre. Many songsters like Blackbirds go to the very top of a tall tree to sing, maximising the number of surrounding surfaces their song will reflect off before reaching their audience lower down.

So, suppose you follow instinct and get close to such a songster with a dish. The bird is very loud in your earphones and you have to turn down the gain to avoid distortion. But this also suppresses the surrounding echo, which gives the singing much of its character. Sure you get a technically stunning recording, almost as if you were right next to the bird. It would be ideal for a sonagram, but as a listening experience it can be flat and dull, with other parts of the sonic landscape so muffled that there's an odd sense of having cotton wool in your ears.

Now imagine moving away. You have to turn the gain up, and the microphone begins to pick up all the surrounding sounds -- including the echo of the song, just as the bird intends it to be heard! Obviously this has its limit when you are so far away that the dish ceases to pick out the singing bird effectively. The balance comes where the sound coming direct from the bird and the echo sound . . well, just right. You know it when you hear it.

In fact of course this is well known to human musicians. It's why we have expensive concert halls, and why so much time is given to designing their acoustic properties -- not least the echo time.

A good illustration of how dominant echo can become is an experience I had with a Cuckoo. It was about 2 am and I was recording owls. The countryside was completely silent apart from a lone Cuckoo calling from about half a mile behind me. I turned to see if I could pinpoint its direction with the dish (i.e. where the signal was loudest) and was surprised to find that the calls sounded almost equally loud over pretty much 180°! In other words, at that distance nearly all the sound arriving at the dish was echo. With headphones off the Cuckoo's direction was quite easy to tell. The unaided ears are good direction detectors, but with headphones on all sound information is coming from two point sources. I often wish there was such a thing as flip-away headphones (flip away from your ears!) as it's all but impossible to tell where a bird is with them on. That's why it's useful to go out with a companion when recording so they can point to birds that start calling unexpectedly.

Anyway, to wrap this discussion up. I believe Klas is right to emphasise the advantages of using a stereo microphone in a parabolic dish. (I have to admit that I'm not certain what mics are used with other, cheaper dish systems on the market, but a quick check suggests that it's usual to place a single omnidirectional microphone at the focus. This, of course, will produce mono recordings.) The four-capsule Stereo DAT mic he's engineered to do this may not be the perfect studio mic with a flat response across all frequencies -- it has that hike in the high treble -- but it works a treat. You can make recordings that get the bird with beautiful close-up clarity and yet at the same time gather the ambient reflections that make bird song such a pleasure to listen to. It would be difficult to do the two things at once with unaided microphones. It's equivalent to having one microphone recording the bird from close by and another more distant mic recording ambience.

Postscript: This description is based on Telinga equipment bought in 2005. Equipment specs may have changed since then. Check with the manufacturer: Telinga website.

Below: some pics showing the Telinga in action

Recording at an owls' nest May 2006

Left: Dawn. The Telinga, on a tripod, is hitched to an HHB Portadisc next to the chair. The two mics on stands are Rode NT1-As connected to an Edirol R4 hard disk recorder (out of view). One faces backwards because a dawn chorus is being recorded. During the night they'd both faced the owls, one aimed directly up at the nest and the other at the wood to the left for ambience. Both setups gave excellent close-up recordings of calls from the nest. The Telinga picked up more traffic noise from the road behind than the directional (cardioid) Rodes.

Right: The nest was near the top of the middle pine in the group just beyond the chicken run. An old crow's nest, it's about 50 feet from the mics.

I often use the Telinga without a tripod, but for long periods of stationary recording like this a tripod is absolutely essential. The dish, mic and handle setup is quite light (I think about 2 lb, or a kilo), but holding anything out from one's body for more than about 10 minutes can become a real pain. A tripod also eliminates all handling noises, and in the case of these owls means that the dish can be precisely trained on the nest (usually by eye, sometimes by sound) and then left.

Recording the nestbox owls April 2006

Left and middle: This was a more serious attempt to follow the activities of a nesting pair, requiring a "hide" and weather protection for the the mic. The nestbox, visible in the left pic, is about 50 feet away. Right: photo from the back showing the gripper adaptor (available from Klas Strandberg) needed to mount the mic handle on a tripod. Again, this was a successful arrangement, allowing recording of everything from the tiniest noises made by mother and chicks to loud interactions between the parents. I did use the Rodes once at this site, but it's further from the house and setting up studio equipment in a dark wood is hard work! It took about 40 minutes, but to my surprise the mother owl, now fairly used to my turning up, stayed put in the nestbox just yards away.

Back to previous page (Telinga p. 1)

powered by owls