Is there a way to achieve this ?
I've seen this schematic and said to myself: 😕
I can understand the logic behind it but i know reality is a different beast so it may have a low degree of success.
Besides, i won't have time to test it until 2 weeks from now ...
I also thought of placing the condenser inside a bell or cone like structure at the closed end but backwards, with it's face facing the bell.
Basically i get a parabolic like receiver.
I have lots of condensers and they give me easily feedback but have excellent sound.
On the other hand i have some dynamics which are somewhat directional and don't give that much feedback but sound awful.
Any help is much appreciated.
I've seen this schematic and said to myself: 😕
I can understand the logic behind it but i know reality is a different beast so it may have a low degree of success.
Besides, i won't have time to test it until 2 weeks from now ...
I also thought of placing the condenser inside a bell or cone like structure at the closed end but backwards, with it's face facing the bell.
Basically i get a parabolic like receiver.
I have lots of condensers and they give me easily feedback but have excellent sound.
On the other hand i have some dynamics which are somewhat directional and don't give that much feedback but sound awful.
Any help is much appreciated.
Attachments
The trouble with the differential cct is that the diaphragms of each mic will be in a different physical plane, resulting in phase cancellation and reinforcement at different frequencies.
Is there a mechanical diagram that goes with the cct?
You could use a bell-like enclosure, but as with a horn, the lowst frequecy is determined by its diameter. To obtain a good f.r. you'd need a big bell!
Quite decent directional electret elements are available at only a little more cost than the omnis.
Is there a mechanical diagram that goes with the cct?
You could use a bell-like enclosure, but as with a horn, the lowst frequecy is determined by its diameter. To obtain a good f.r. you'd need a big bell!
Quite decent directional electret elements are available at only a little more cost than the omnis.
As you can see the picture is not very telling but basically the capsules are tied together back2back at a distance just enough to not short.
Funny, i couldn't find any uni condensers around here ...
Maybe in england.
I don't care very much about the lower end. If it gets down to 200Hz i'm up high. I just need a sensitive device like a condenser is and for it to be directional let's say it's angle should be 45dg.
Funny, i couldn't find any uni condensers around here ...
Maybe in england.
I don't care very much about the lower end. If it gets down to 200Hz i'm up high. I just need a sensitive device like a condenser is and for it to be directional let's say it's angle should be 45dg.
Attachments
The trouble with the differential cct is that the diaphragms of each mic will be in a different physical plane, resulting in phase cancellation and reinforcement at different frequencies.
Is there a mechanical diagram that goes with the cct?
You could use a bell-like enclosure, but as with a horn, the lowst frequecy is determined by its diameter. To obtain a good f.r. you'd need a big bell!
Quite decent directional electret elements are available at only a little more cost than the omnis.
Is there a mechanical diagram that goes with the cct?
You could use a bell-like enclosure, but as with a horn, the lowst frequecy is determined by its diameter. To obtain a good f.r. you'd need a big bell!
Quite decent directional electret elements are available at only a little more cost than the omnis.
Neat idea! About that plane and cancelation thing, I think one can get capsules closer side to side than back to back. Like this:
http://www.mp3forkidz.com/mic/mod.html
http://www.mp3forkidz.com/mic/mod.html
Sorry abut the double post - ite didn't register first time so I re-submitted.
I agree that side-by-side would work better than back-to-back.
Electret capsules are so cheap that you might try experimenting with drilling a ring of holes in the rear of the body to convert an omni into a directional.
I agree that side-by-side would work better than back-to-back.
Electret capsules are so cheap that you might try experimenting with drilling a ring of holes in the rear of the body to convert an omni into a directional.
I have a fair number of these things, and have fooled with various mods people have published, like cutting the traces and adding a source resistor. No matter what I did, the combination of small diaphragm and internal FET still resulted in a mic with too much noise. For a measuring mic, they can work well because you can deal with the noise and they're quite flat. For a recording mic, I'm not so impressed. Better to invest the $57 or whatever, for a cheap studio type condenser with a large gold sputtered diaphragm. You'll have to build a phantom supply and maybe a preamp. Once you hear that, the little cartridges lose much of their appeal, though the big mics are far from flat.
" .. I agree that side-by-side would work better than back to back ..."
Dual element mics, side by side or top to bottom: This is similar to those funny looking microphones used by the Greatful Dead during the late eighty's and ninty's ... the principle being to cross cancel the background noise, yet let the musician's voice come through on top. The mics are each feed into seperate op-amp pre-amps, one inverting op-amp, one not ... then mixed into the line output driving XLR mic cables to the main mix down console ... worked pretty well (if you can stand the Dead's medeoker to bad vocals ...) I set up a similar dual combo mic for Mimi Farina once, one hot, but distant, one not, but in her face ... she liked it fine until she grabbed the weak link mic and pulled away from the hot mic = a frantic search at the mix console to crank up the mobile mic and reduce gain on he "hot" one.
early prototype: http://i.realone.com/assets/rn/img/5/4/6/0/8900645-8900648-slarge.jpg
Dual element mics, side by side or top to bottom: This is similar to those funny looking microphones used by the Greatful Dead during the late eighty's and ninty's ... the principle being to cross cancel the background noise, yet let the musician's voice come through on top. The mics are each feed into seperate op-amp pre-amps, one inverting op-amp, one not ... then mixed into the line output driving XLR mic cables to the main mix down console ... worked pretty well (if you can stand the Dead's medeoker to bad vocals ...) I set up a similar dual combo mic for Mimi Farina once, one hot, but distant, one not, but in her face ... she liked it fine until she grabbed the weak link mic and pulled away from the hot mic = a frantic search at the mix console to crank up the mobile mic and reduce gain on he "hot" one.
early prototype: http://i.realone.com/assets/rn/img/5/4/6/0/8900645-8900648-slarge.jpg
wxn:
One of the capsule has to be cardioid and i have only omnis. If i could get my hands on any cardioids i wouldn't be here.
dnsey:
i've read that the backholes are rather well calculated and executed in the number an diameter. I'll experiment when i have time.
Conrad Hoffman:
The intended use is for live sound, well, kinda (basically indoors with some speakers outside but only ocasionally).
But absolutely no for recording.
57$ you say, i only got around this one for that amount so ...
And i need about 4 of them in the worst case and better would be 8 so you feel my pain.
I am very satisfied with the sound these tiny capsules provide. I also have some dynamic but these tend to sound like a tin can ...
And i allready am in the mid of building preamps/mixer/phantom power
FastEddy:
Nice. But my mikes will be placed downfiring in a fixed position at 0.5m to1m above the speaker(s)/singers(s).
Somebody suggested i build a mike array. Say for each place where sound needs to be captured i place let's say 8 or more of these capsules in a spatial pattern that covers the possible movement of the person (which is quite small, let's say 5m/3m) and all of them turned down in volume so they add up in the mixer.
I shall see what i can do about them holes 😀
One of the capsule has to be cardioid and i have only omnis. If i could get my hands on any cardioids i wouldn't be here.
dnsey:
i've read that the backholes are rather well calculated and executed in the number an diameter. I'll experiment when i have time.
Conrad Hoffman:
The intended use is for live sound, well, kinda (basically indoors with some speakers outside but only ocasionally).
But absolutely no for recording.
57$ you say, i only got around this one for that amount so ...
And i need about 4 of them in the worst case and better would be 8 so you feel my pain.
I am very satisfied with the sound these tiny capsules provide. I also have some dynamic but these tend to sound like a tin can ...
And i allready am in the mid of building preamps/mixer/phantom power
FastEddy:
Nice. But my mikes will be placed downfiring in a fixed position at 0.5m to1m above the speaker(s)/singers(s).
Somebody suggested i build a mike array. Say for each place where sound needs to be captured i place let's say 8 or more of these capsules in a spatial pattern that covers the possible movement of the person (which is quite small, let's say 5m/3m) and all of them turned down in volume so they add up in the mixer.
I shall see what i can do about them holes 😀
I'm back, large as life and twice as ugly 🙂
So i drilled them holes.
Man, now that's a lot of work. The back of the capsule is thick man.
And hard.
Seriously man. IT'S REALLY HARD. It's about 2mm thick and took me roughly 5 min/hole.
I first did only one. You know, to see the "noise canceling" effect.
Well, it worked. After the first 20cm sensitivity dropped like a rock.
Then i drilled another 4 holes (wanted 5 but couldn't, no more space).
Yes, this thing gets directional. My impression is that it's a fig.8.
Or almost a cardioid in front and another one in the back. Anyway, it has direction.
Now, the thing is, the sound level compared to a non-holed capsule has dropped to around half.
I must admit, i might have drilled them holes too much 😡
I may have touched the electret membrane (have no clue how these things are built inside) or even perforated it, dunno ...
Will run more tests, with a stopper on my drill, hopefully
So i drilled them holes.
Man, now that's a lot of work. The back of the capsule is thick man.
And hard.
Seriously man. IT'S REALLY HARD. It's about 2mm thick and took me roughly 5 min/hole.
I first did only one. You know, to see the "noise canceling" effect.
Well, it worked. After the first 20cm sensitivity dropped like a rock.
Then i drilled another 4 holes (wanted 5 but couldn't, no more space).
Yes, this thing gets directional. My impression is that it's a fig.8.
Or almost a cardioid in front and another one in the back. Anyway, it has direction.
Now, the thing is, the sound level compared to a non-holed capsule has dropped to around half.
I must admit, i might have drilled them holes too much 😡
I may have touched the electret membrane (have no clue how these things are built inside) or even perforated it, dunno ...
Will run more tests, with a stopper on my drill, hopefully
Yeah, well, ok, i noticed that.
But the new "holed" capsule has no "front" or "back" meaning it sounds equally from front or back.
That's why i said it resembles more a fig.8 than a cardioid. Maibe if i place something behind it ... well see.
But the new "holed" capsule has no "front" or "back" meaning it sounds equally from front or back.
That's why i said it resembles more a fig.8 than a cardioid. Maibe if i place something behind it ... well see.
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