This capsule is also used in the KM83, KM130 and KM183.kingkorg said:
‚Honeycomb‘ reflectors are also used in Schoeps capsules.
DIY M50 capsule
- Thread starter kingkorg
- Start date
Help Support GroupDIY Audio Forum:
‚Honeycomb‘ reflectors are also used in Schoeps capsules.
Not realized yet, but I bought this:
https://www.ebay.com/itm/40mm-Diameter-Solid-Round-Acrylic-Sphere-Plexiglass-Ball-Ornament-Clear-5pcs/183144669862?epid=18002459477&_trkparms=ispr%3D1
and
thought about this:
https://www.ebay.de/itm/Oktava-MK-012-Omni-Capsule-Stereo-Pair-Silver-Brand-New-Free-Shipping/220400195022?hash=item3350e015ce:g
vAAAOSwB0hcfEMp
I think that this would be the best price performance combination. The only thing I don't know, how much polarization voltage this capsule need.
Would be voltages from M50 schematics sufficient ?
Thanks
https://www.ebay.com/itm/40mm-Diameter-Solid-Round-Acrylic-Sphere-Plexiglass-Ball-Ornament-Clear-5pcs/183144669862?epid=18002459477&_trkparms=ispr%3D1
and
thought about this:
https://www.ebay.de/itm/Oktava-MK-012-Omni-Capsule-Stereo-Pair-Silver-Brand-New-Free-Shipping/220400195022?hash=item3350e015ce:g
vAAAOSwB0hcfEMpI think that this would be the best price performance combination. The only thing I don't know, how much polarization voltage this capsule need.
Would be voltages from M50 schematics sufficient ?
Thanks
If it's 57v as specified in schematic, it should work just great.
As i used ST51 for this experiment 40v was a bit low, some noise issues at distance.
So i used an extra DC-DC board i had from Behringer B2 to get 60V, and it works great with my capsule.
edit:
Now that i am actually looking at the schematic for the first time, as i was going for Fet version, i see that 600pf cap anode to ground. Hm...
As i used ST51 for this experiment 40v was a bit low, some noise issues at distance.
So i used an extra DC-DC board i had from Behringer B2 to get 60V, and it works great with my capsule.
edit:
Now that i am actually looking at the schematic for the first time, as i was going for Fet version, i see that 600pf cap anode to ground. Hm...
https://s.click.aliexpress.com/e/oSIraolT9 ;D
I have no m50 to compare it to, but it measures exactly as it should, and sounds great.
As it's meant to be a far mic the circuit is afjusted for lowest noise, not highest headroom.
So the capsule is polarized at about 80v, fet rebiased for highest output. It is very low noise, in range with my Shure KSM44.
I have no m50 to compare it to, but it measures exactly as it should, and sounds great.
As it's meant to be a far mic the circuit is afjusted for lowest noise, not highest headroom.
So the capsule is polarized at about 80v, fet rebiased for highest output. It is very low noise, in range with my Shure KSM44.
Attachments
Better late than never. So here's shootout of some of my ''clones'' against this fet version of M50 with my diy capsule.
I think the goal is achieved and it does what it's supposed to. It ''grabs'' wonderfully high end at distance, which is obvious on hi hat, and low end response is better that LDCs in the shootout. This is exactly opposite of stock capsule which was all midrange, and sharp peak at 8k, which doesn't exist any more.
My clones used in this shootout are u87, u67, u47, m50 and ECM8000 as a refference mic. All of which in omni mode.
Bear in mind it's not one take, it's one for each mic.
https://app.box.com/s/sxy3j8o6gvhsb5kz9g6jecsu7a0xamht
I think the goal is achieved and it does what it's supposed to. It ''grabs'' wonderfully high end at distance, which is obvious on hi hat, and low end response is better that LDCs in the shootout. This is exactly opposite of stock capsule which was all midrange, and sharp peak at 8k, which doesn't exist any more.
My clones used in this shootout are u87, u67, u47, m50 and ECM8000 as a refference mic. All of which in omni mode.
Bear in mind it's not one take, it's one for each mic.
https://app.box.com/s/sxy3j8o6gvhsb5kz9g6jecsu7a0xamht
Is it really that simple to convert a cardioid capsule to an omni capsule,
by just blocking the holes in the (plastic) second backplate?
In the Neumann book "Microphones" at page 27 there is a picture of how different types of capsules are "tuned" (and why).
Condenser pressure microphones have a diaphragm that is "high frequency tuned", condenser pressure gradient microphones have a diaphragm that is "mid frequency tuned".
This is also the reason why condenser pressure microphones are less susceptible to disturbance by wind
and body noise, footfalls, handling noises, etc. The diaphragm is "stiffer".
Any thoughts on that?
by just blocking the holes in the (plastic) second backplate?
In the Neumann book "Microphones" at page 27 there is a picture of how different types of capsules are "tuned" (and why).
Condenser pressure microphones have a diaphragm that is "high frequency tuned", condenser pressure gradient microphones have a diaphragm that is "mid frequency tuned".
This is also the reason why condenser pressure microphones are less susceptible to disturbance by wind
and body noise, footfalls, handling noises, etc. The diaphragm is "stiffer".
Any thoughts on that?
Well it isn't just closed at the back, there is a ball around it that does it's own thing. The pattent documents explain it in detail.
Also, the m50 capsule is not purely omni, its directivity is changed through the frequency spectrum, and it's unique mix of omni and cardioid.
I don't have the original capsule to compare it to, but the measurements i have taken and posted here confirm that it behaves as it should.
Also, the m50 capsule is not purely omni, its directivity is changed through the frequency spectrum, and it's unique mix of omni and cardioid.
I don't have the original capsule to compare it to, but the measurements i have taken and posted here confirm that it behaves as it should.
Btw, it is a piece of cake to tune this diaphragm tighter if one has gold plated mylar, i have done it several times. No tools required. It does make sense for some capsules, but diaphragms for km84 and similar Neumans don't have higher tensioned diaphragms for omni capsules compared to cardioids. One of the M50 versions has just km84 type capsule stuck into a sphere, just like this one.
I'm also planning on building the M50's. Lately i'm doing some orchestral work, and a nice decca tree of M50's would be nice.
I'm taking a little different approach, which is closer to the original, but of course more expensive.
I'm taking the KK83 (KM83 capsule) and put a sphere around it. In some of the original M50's there was this capsule installed, so it's bassically the same. And the KK83 capsule is sometimes easy to find. I paid about €600 for 2 pieces, which is reasonable IMO.
I'm taking a little different approach, which is closer to the original, but of course more expensive.
I'm taking the KK83 (KM83 capsule) and put a sphere around it. In some of the original M50's there was this capsule installed, so it's bassically the same. And the KK83 capsule is sometimes easy to find. I paid about €600 for 2 pieces, which is reasonable IMO.
Nice work Matija!
Did you considered to make metal "ball" with mesh and leave it opened without outside headbasket?
It could work and definately it would look fantastic. I love IRT V30 visual design. There of course head wasn't to create omni pattern but i belive it could work this way.
Did you considered to make metal "ball" with mesh and leave it opened without outside headbasket?
It could work and definately it would look fantastic. I love IRT V30 visual design. There of course head wasn't to create omni pattern but i belive it could work this way.
Influenced . . .
Project in progress for a Decca tree: fet-version of the M50 idea. UTM transformer.
k brown
Well-known member
Don't know if you're using the exact capsule KK showed in his first posts, but to obtain an M50 response, the capsule itself needs the response shown in the first pic. If the capsule has a flat response and is used with a 40mm sphere, the mic will have the response shown in the second pic. The M50's response is the combination of the two curves. For a flat response capsule, you'll want to use a 50mm sphere.
Attachments
I used Pronomic SCM1 and Takstar CM-60.
Picture of a Takstar capsule and the result after some sawing, filing and sanding.
Aren’t these cardioid capsules?
Cardioid indeed. You have to close the capsule to turn it into omni.
Which circuit did you use for this?
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