Mono vs Stereo for sonagrams (1 Viewer)

I see there are stereo (for example, Telinga Twin Science) and mono setups for parabolas. My assumption is if my intent is sonagram analysis, I want to eliminate sounds not from the target source. The stereo setups (omni-directional stereo pointing away from dish) give the impression that the goal is to capture ambient sound in addition to the target source.

To me, this suggests Mono is better for sonagram study, and stereo setups better at capturing nature sounds for other applications. Is this correct? What are people's experience with mono versus stereo parabolas?

The Twin science consists of two mics which let you select which mono signal you prefer. It is not a stereo mic, it merely uses the two tracks to record two variants of a mono signal.

from http://www.telinga.com/choosing.htm

Mono: Twin Science:
A microphone with two mono capsules, one omni facing outwards of the dish and a directional microphone facing inwards. The two microphones will record separately to respective stereo track:
The “Omni” track: Very low handling noise and wind noise.
The “Directional” track: Better frequency response.

Click to expand...

other than that, you are entirely correct. Unlike the ear, sonograms have no spatial discrimination against other sounds, and do not use stereo - if feeding a stereo signal into Raven, for instance, it will ask you to select which channel to use.

You ideally want the desired signal isolated from all other sounds, which means you need to either get very close, or use a directional mic. A parabolic dish mic gives the highest amount of directionality, at the cost of distorting the frequency response which isn't usually too much of an an issue for sonograms.

Thanks, Ermine! You're correct, the Twin Science is dual mono. I was also thinking of the Telinga Stereo DATmic which "provides both a mono signal of the focused sound and a stereo picture of the ambience."

Regardless, thanks for the feedback. I decided to start out a little lighter than a parabola, and went for the Sennheiser ME-67. I've only used it once, but I'm surprised on a windless day how much noise it picks up -- I assume from roads and distant highways. This white/pink (don't know the difference) noise disappears as I pull it back inside the window. I guess that's another feature of the parabola: shielding the mic from unwanted noise as much as gathering from your target source!

the parabola collects sound from a much larger area and concentrates it on the mic; you therefore get noiseless gain.

While a parabola will give you a lot of gain, you should be able to make good bird recordings at ranges of up to about 20 yds with a ME67 (distance varying with loudness of signer and ambient noise) and the sound will be less coloured than that of a parabola. If you have access to a ME 67 you have excellent gear and should get some good recordings with good fieldcraft - don't give up on it!

> don't give up on it!

Thanks! No, I can't give up, too exciting. I notice it's not only learning fieldcraft, but also the computer tools, not to mention adjusting expectations with results.

Yes, I bought the ME67 along with a Marantz PMD661. I suspect this will turn into a parabola sooner than I expected. :eek!:

It's great hearing how sensitive the mic is -- I hear more when it's on, but then even more during playback. It's a great learning experience already. For example, while recording I captured our resident Northern Mockingbird giving his loud "CHEWP!" But on playback, I hear he did it in direct response to a distant calling Mockingbird. Cool!

I may have recorded an immature Song Sparrow "practicing" 2 songs... sometimes just the opening sounds, other times adding or subtracting elements, singing each only once before switching to the other song. Can anyone confirm whether this fits a rehearsing sparrow or whether this is typical in normal adult singing?

Also, do Starlings (S. Vulgaris -- "Common" Starling in UK?) exhibit bill clapping during mating or territorial displays? If so, anyone know whether this is single claps, or a quick series? I hear/see a figure that struck me as a bill, but realize Starlings are so vocally acrobatic that it could be a clicking vocalization.

Not sure how to put in images:
http://www.prism.net/user/buile/starling-c.jpg