"The remainding question is... will be any suitable 30mH inductor wich could be used, that fits a regular BM700/800 mic body?" - I do not know how much space/how many millimeters are available in the body, but have a look at?
(for some reason this time AliExpress switched to Russian).
Two more things:
1) take into account that the inductor itself has some DC resistance - which can be measured by multimeter and should be subtracted from the R in the three component notch filter;
2) as I wrote earlier, the bigger L is (accompanied by proportionally decreased C), the narrower the dip is. I.e. maybe 47mH or 50mH as two parallel 100mH inductors can be more appropriate. One really has to have the capsule magnitude plot before his eyes to properly pick L.
--Sergei.
P.S The inductor can suck in AC hum magentic field. I.e. one might need some ferrous metal ring inside the microphone body around the are where the inductor is located. OTOH, a humbucker coil consisting of two inductors can be constructed.
I suggest to start from plain single inductor and field test it.
On Tuesday, January 8, 2019, 9:43:15 PM GMT+2, homero_leal@... [micbuilders] wrote:
?
It works Sergei!
Did the sim using values of 30mH, 1.5k and 8200pf, and this is the resulting FR graph:
There is a signal atenuation of aprox. 2.7dB at about 10kHz,?
Looks really good for the application Pat mentined on his previous post.
The remainding question is... will be any suitable 30mH inductor wich could be used, that fits a regular BM700/800 mic body?
Thank you and kind regards!
HL
