EdCampbell
Newbie level 4
Hi firstly I am new here and would like to say that I am more of a hobbyist than an expert in electronics, However right now I am working on a phantom powered electret microphone for use as a direcional mic. The design of the mic amp is not mine, and is in a way a balanced output and is powered via the mixer phantom power system. I have found how ever that I get a sort of ring at certain frequencies and I get feed back in the range of about 600 to 1.25 khz. I have reduced the mic sensitivity quite a bit but may have to go even lower. What I am thinking of is putting a pasive filter sytem to help reduce the feedback in the mid frequency range and obviously the hi range so as to make equalization on the mixer a lot easier. My question is where does one put the filters just after the mic capsule or on the output going to the mixer. I am not sure if I would be allowed to upload the schematic as according to your rules no copyrighted stuff to be uploaded. Maybe I can give the link to where I got the circuit for those who wish to see it in order to understand my plight. So will leave this post and wait for answers from Admin etc before I continue. Here is the link the the schematic. https://sound-au.com/project93.htm
I have changed the values of R8 and R2. R8 is now 2.2 kilo ohm, and R2 is 4.7 Kilo Ohm. Looking at the schematic where would it be best to put the filters.
Just a comment, as is it works really well but my mixer which is a Soundcraft Signature mtx22 is quite sensitive even though the max input on the balanced input for each channel is +12db. By the way the ring I hear is on the prefade listend and the channel fader and all other aux faders down. So it is due to the mic frequency response to high notes.
I have changed the values of R8 and R2. R8 is now 2.2 kilo ohm, and R2 is 4.7 Kilo Ohm. Looking at the schematic where would it be best to put the filters.
Just a comment, as is it works really well but my mixer which is a Soundcraft Signature mtx22 is quite sensitive even though the max input on the balanced input for each channel is +12db. By the way the ring I hear is on the prefade listend and the channel fader and all other aux faders down. So it is due to the mic frequency response to high notes.