Exactly. But a Mix of Omni and Cardioid can also be useful.
We know that the capsules have nearly Schoeps Level. Would be nice to have professionell Sound for 5% money...
If only two mics... ?
- Thread starter Emmathom
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We know that the capsules have nearly Schoeps Level. Would be nice to have professionell Sound for 5% money...
Barry Hufker
Well-known member
I did so (closing the vents) on my sE8 cardio pair telling myself "no need to spend 200€ more to get 2 omni capsules"... but unfortunately it didn't sound like the original omni capsules... (I had both cardio & omni capsules at this time).
Is there a reason why ???
Is there a reason why ???
Barry Hufker
Well-known member
I'm guessing it's the design. One design is optimized for cardioid and so makes a poor omni. But the MK5 (and 141) have been designed to be switchable from the start so all parameters are optimized for that...
Here is what Schoeps says about MK5 :
Although it only has one diaphragm, the MK 5 capsule allows you to choose between two directivity characteristics. Switching is strictly mechanical and is accomplished using a side-mounted slide switch.
So perhaps Ulli's intend to build an omni mic with S502's cardio capsule is doomed to failure... ?
k brown
Well-known member
There is more going on in those Schoeps capsules than simply covering the slits in the external shell. Internal changes, as well.
Many SDC cardioid capsules can be succesfully converted to omni, but it requires plugging holes in the actual backplate of the capsule (not just the housing slots), and usually additional changes to internal spacers, requiring disassembly of the capsule.
Covering up only the external slots creates a resonant, trapped air space behind the diaphragm, messing up the response.
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That's what I got covering the vents of my sE8 cardio.
I knew there was something more to do than just covering the vents (and read it somewhere in groupdiy some months ago).
I guess It must be the same for the Shure KSM141...
k brown
Well-known member
What can often work fine is covering half the slits to produce a sub-cardioid response; doing this doesn't create a sealed volume of air behind the diaphragm.
If you intend to dedicate a mic to omni mode then I guess you'll be able to deal with this bass boost (electronicaly ?).Everything may work fine when the sealed volume is small enough. With the S502MKII capsules closed i can hear a bass boost but no irregularities. I would suggest it is around +6dB. Hopefully i can measure it soon
But I doubt if you'd like to make a switchable pattern version of this S502 (but that's not your goal, isn't it ?)
The 'diaphragm resonance' of a cardioid, Fig 8 or other directional mike is at mid frequency ... near 1kHz.
An omni must have it's resonance near the top of its frequency range ... above 10kHz usually.
Plugging the holes in the capsule may raise the 'resonance' high enough but plugging the vents won't do it. You'll get HUGE mid/LF boost.
I had some curves showing this but lost them in a couple of HD crashes
An omni must have it's resonance near the top of its frequency range ... above 10kHz usually.
Plugging the holes in the capsule may raise the 'resonance' high enough but plugging the vents won't do it. You'll get HUGE mid/LF boost.
I had some curves showing this but lost them in a couple of HD crashes
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so electronically, no : but mechanically, perhaps... by plugging the backplate's holes
Perhaps we need to stuff the tube, and seal the back of the capsule, with modeling clay or SillyPutty(R), or even chewing gum, to choke the back of the capsule and also close the vents while filling the void inside the tube . . . ?
Just a wild thought that came to mind. James
k brown
Well-known member
Here are my measurements. S502MKII capsule vents were sealed with self adhesive tape. BLUE curve, shows a 12dB bass boost around 180Hz and a 4dB dip at 5kHz. A three stage EQ leads to the RED curve, for my oppinion not bad at all. For comparison the cardioid S502MKII in GREEN. Of course we have a limited dynamc range, the max. SPL at lower frequencies will be limited to approx. 122dB...
Pls take the measurements with a grain of salt. No reference mic and not the best speaker at all, measurement distance was 50cm.
But if we consider the trivial approach with adhesive tape it is surprising how cheap an omni can be done
BR MicUlli
Pls take the measurements with a grain of salt. No reference mic and not the best speaker at all, measurement distance was 50cm.
But if we consider the trivial approach with adhesive tape it is surprising how cheap an omni can be done
BR MicUlli
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Interesting Ulli... what about the EQ please ? which types, which Fs, how much dB, etc... ? Can you tell us your setup ? or a pict of the EQ in your DAW ? Indeed, a preset EQ can be store in the DAW and recalled when S502 is used in omni mode. For example here is a screenshot of my EQ on the PUI5024 omni little mics where you can see all about the EQ...Here are my measurements. S502MKII capsule vents were sealed with self adhesive tape. BLUE curve, shows a 12dB bass boost around 180Hz and a 4dB dip at 5kHz. A three stage EQ leads to the RED curve, for my oppinion not bad at all. For comparison the cardioid S502MKII in GREEN. Of course we have a limited dynamc range, the max. SPL at lower frequencies will be limited to approx. 122dB...
Pls take the measurements with a grain of salt. No reference mic and not the best speaker at all, measurement distance was 50cm.
But if we consider the trivial approach with adhesive tape it is surprising how cheap an omni can be done
BR MicUlli
122dB max. is not an issue since omnis are (mostly) used for ambiance recording (not close to kick drum)
So to get something more clean than"adhesive tape" a nice & thin ring (brass?) can be threaded on the capsule when needed... (in a "will you marry me" style
)Regards
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Yes, thats true. The EQ parameters areInteresting Ulli... what about the EQ please ? which types, which Fs, how much dB, etc... ? Can you tell us your setup ? or a pict of the EQ in your DAW ? Indeed, a preset EQ can be store in the DAW and recalled when S502 is used in omni mode. For example here is a screenshot of my EQ on the PUI5024 omni little mics where you can see all about the EQ...
122dB max. is not an issue since omnis are (mostly) used for ambiance recording (not close to kick drum)
So to get something more clean than"adhesive tape" a nice & thin ring (brass?) can be threaded on the capsule when needed... (in a "will you marry me" style
Regards
PK Fc 180.0 Hz Gain -12.00 dB Q 0.200
PK Fc 4000 Hz Gain 4.00 dB Q 0.300
PK Fc 12500 Hz Gain -3.00 dB Q 1.000
This gives a first shoot for good sound. Can be refined later after exact measurements...
something like this ?
You did not precise but I guessed that 180Hz is high-pass and 12,5kHz is a low-pass
Note that the curve flips negative to positive @ 1kHz...
But the issue isn't it a strong level in the lows that may influence the whole recording level ?
Could it be possible (just asking) to add a "XLR interface" (see attached please) directly plugged in the mic (like the TritonAudio Fethead) which add passive EQ at recording ? Maybe just to damp the lows by 6 or 9dB ? so the recording level would not be "overload" by lows... ? But this passive EQ (R + capasitor) should not modify the sound and that's the goal I guess...
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