The single electret capsules are performing
admirably in that rig. What type are they? Let us
know if you determine/solve the source of the
buzz.
At 10:09 PM +0000 6/5/06, tk7859 wrote:
>Hello Rob and the Group
>
>--- In Rob Danielson <> wrote:
>
>> Hi Tom--
>> I couldn't download the volume matched file but after boosting the
>> DIYCaps/Jecklin section +2.6dB and the NT4 section +13 dB to match
>> volume, the stereo imaging with your DIY rig is much more interesting
>> to me and, if you can rid the buzz (~4K Hz and up) from your DIY rig,
>> I'd head out with it over an NT4 any day. Perhaps some shielding on
>> the back of the caps or elsewhere would help?
>
>
>I was monitoring both NH1s from the comfort of my dining room. The
>NT4's NH1 was next to me and I therefore used headphones with a short
>cable. The Jecklin's NH1 was ouside in the garden and I had to use
>headphones with an eighteen ft. cable. Possibly this was a cause of
>the hum pickup.
>
>> To my ears, the NT-4's stereo image is very compressed towards the
>> center and the cuckoo call with the NT-4 is harmonically simplified
>> compared to your DIY Tri-Capsule Jecklin rig. I assume you removed
>> the attenuation circuit from your NT-4 cable (if it came with one).
>
>I used NT4 cables that did not have the attenuator.=A0
>
>For this dawn chorus test I used the more sensitive single capsules
>rather than the triplets (easily done using a modular mounting system
>so that I can use singles or triplets on the jecklin disc and also on
>the parabolic reflector). BTW, the reflector is now finished and
>operational. The focal zone was found to be very close to the
>designed 12.5 cm from the base of the dish. It works well in the
>garden but needs testing on the saltmarsh. I will report on this when
>it is done.
>
>This evening I did some tests to check the relative sensitivity of the
>single capsule and triple capsule stereo setups (in the Jecklin) and
>the NT4.
>
>The test was to measure the manual volume setting on the NH1 at which
>the bargraph just reached the -12 dB spot. The sound source was pink
>noise from an off tuned FM radio 12 ft. away.
>
>The results confirmed the sensitivity ranking and were:-
>
>Single capsule stereo 16
>NT4 21
>Triple capsule stereo 27
>
>Cheers
>
>Tom
>
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>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>
--
Rob Danielson
Peck School of the Arts
University of Wisconsin-Milwaukee
http://www.uwm.edu/~type/audio-art-tech-gallery/
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