k brown
Well-known member
Without the dough for a Schoeps KFM 6 (~$8,000), KFM 360, or even a T.H.E. BS-3D (~$2,500) - all three now discontinued anyway - I decided to make a budget version based on Hudson Fair's ('Plush' on Gearspace) opinion that the KFM 6 sphere would have been more useful if it were the smaller 7" size of the KFM 360 (see his post below).
Found a dense solid-foam 7" ball on Amazon ($15) that is way heavier and 'deader' than the cheap styro wig heads many use for 'binaural' mic projects. Reviews on Amazon say that any kid that gets whacked on the nose with one of these 'play balls' is gonna have a nosebleed! This is no Nerfball!
Mounted a pair of Audio Technica ES945 boundary mics (cheap on eBay) in it, that have a frequency response very close to the Schoeps MK 2XS used in the KFM 6. Removed the circuit board and XLR insert from the 945s, hardwiring the cables to the FET of the capsules. Can use with any of several AT power modules designed for the 2SK660 FET (most of them are). The foam is firm enough to hold the threaded mic bodies in place by friction alone.
The ball was only available in red, so covered with gunmetal grey Plasti Dip (still needs a second coat).
At about 1lb.,the finished mic is very lightweight compared to any of the commercial models (KFM 6 - 2 1/4 lb., Neumann KU 100 - 3 1/4 lb., BS-3D - 3lb.) - as to whether the ball is acoustically inert enough not to color the sound; only tests will tell - certainly far superior to styro!!
One hitch is that the ball doen't show up on Champion Sports' website, so the ones on Amazon may be limited stock clearance.
By the way - there was a minor error in 'Plush's' post: The recording angle of a 7" sphere is 120 degrees (same as 60cm spaced omnis) , not 110 degrees (the 8" KFM 6 angle was only 90 degrees).
Found a dense solid-foam 7" ball on Amazon ($15) that is way heavier and 'deader' than the cheap styro wig heads many use for 'binaural' mic projects. Reviews on Amazon say that any kid that gets whacked on the nose with one of these 'play balls' is gonna have a nosebleed! This is no Nerfball!
Mounted a pair of Audio Technica ES945 boundary mics (cheap on eBay) in it, that have a frequency response very close to the Schoeps MK 2XS used in the KFM 6. Removed the circuit board and XLR insert from the 945s, hardwiring the cables to the FET of the capsules. Can use with any of several AT power modules designed for the 2SK660 FET (most of them are). The foam is firm enough to hold the threaded mic bodies in place by friction alone.
The ball was only available in red, so covered with gunmetal grey Plasti Dip (still needs a second coat).
At about 1lb.,the finished mic is very lightweight compared to any of the commercial models (KFM 6 - 2 1/4 lb., Neumann KU 100 - 3 1/4 lb., BS-3D - 3lb.) - as to whether the ball is acoustically inert enough not to color the sound; only tests will tell - certainly far superior to styro!!
One hitch is that the ball doen't show up on Champion Sports' website, so the ones on Amazon may be limited stock clearance.
By the way - there was a minor error in 'Plush's' post: The recording angle of a 7" sphere is 120 degrees (same as 60cm spaced omnis) , not 110 degrees (the 8" KFM 6 angle was only 90 degrees).
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