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Gear / Technical Help => Microphones & Setup => Topic started by: Roving Sign on May 10, 2007, 08:34:32 PM

Title: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: Roving Sign on May 10, 2007, 08:34:32 PM
Got these in a lot - the markings are just stickers - not really from the manufacturer - I'll crack them open later...(not sure if they are phantom or battery...)

Anyone ever see anything like this...?
Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: rowjimmy on May 10, 2007, 09:09:51 PM
Looks akin to the kfm-6 dummy head mic from Schoeps but theirs isn't black...

Am I right in thinking that they are binaural mics?

Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: Church-Audio on May 10, 2007, 09:34:39 PM
Got these in a lot - the markings are just stickers - not really from the manufacturer - I'll crack them open later...(not sure if they are phantom or battery...)

Anyone ever see anything like this...?


I think I have seen these before.. When you crack them open post some pictures.. :)
I dont remember where I have seen these.. I am thinking Astatic.. But I am not 100% sure..


Chris
Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: Roving Sign on May 11, 2007, 09:05:33 AM
A bit of an update - I did open them - they have 2 AA battery holders, a transformer, and little circuit board - so safe to say they are battery powered. Looking DIY - although the balls look manufactured...pics to follow soon...

I have a noon recording appointment - maybe I can test these out...
Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: Church-Audio on May 11, 2007, 10:00:22 AM
A bit of an update - I did open them - they have 2 AA battery holders, a transformer, and little circuit board - so safe to say they are battery powered. Looking DIY - although the balls look manufactured...pics to follow soon...

I have a noon recording appointment - maybe I can test these out...

Kinda looks like this...
http://users.cwnet.com/kant/sphere.htm
Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: Roving Sign on May 11, 2007, 03:11:04 PM
Ok - ran these this afternoon - less than optimal anything at this gig -

But - surprisingly good results...

Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: Church-Audio on May 11, 2007, 03:16:05 PM
Ok - ran these this afternoon - less than optimal anything at this gig -

But - surprisingly good results...



Wow really interesting.
Looks like a Panasonic capsule and they used a transformer to balance the output of the mic. I wonder what it would sound like if you whent unbalanced out and ditched the transformer?? But ether way very cool.. I can see doing some mods to that lol.. Like putting in low noise preamp there is so much room inside there lol wonder why they put in insulation lol :)

Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: WiFiJeff on May 11, 2007, 05:40:14 PM
That's not insulation, that's gelignite.  The damn thing looks like a cartoon anarchist's bomb, complete with hole for fuse. 

Jeff
Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: DSatz on May 11, 2007, 07:01:40 PM
Assuming that it's not quite like what WiFiJeff said, then these are basically omnidirectional microphones arranged so that they keep their sonic focus even at rather great distances in a reverberant space.

Embedding a pressure transducer in the surface of a sphere and aiming the transducer forward toward the main sound source has two potentially useful effects for distant pickup: It creates a forward "preference" in the directional pattern above a few kHz, and it emphasizes the upper midrange (= presence) range of frequencies in the front hemisphere of the mike while doing more or less the opposite on the back side.

Attached is a polar diagram for one incarnation of the Neumann M 50 (which used a smaller internal sphere--only 40 mm, or about 1-1/2" in diameter) so that you get a general idea about what the sphere is doing. Among other uses, this is the prototypical "Decca Tree" type of microphone.

--best regards
Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: Kindguy on May 11, 2007, 08:15:22 PM
What Lot did you find these in? At a show?
Title: Re: ID these unusual spherical mics? DIY? Cool? Useful?
Post by: Kindguy on May 11, 2007, 08:35:19 PM
That's not insulation, that's gelignite.  The damn thing looks like a cartoon anarchist's bomb, complete with hole for fuse. 

Jeff

All you need is a mini me, set of darryn's cables. BOOOOOOOOOOOM!

Ok maybe this was tasteless.  ;D Tasteless but funny  >:D