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John Curl's Blowtorch preamplifier part II
John Curl's Blowtorch preamplifier part II
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Old 14th November 2012, 11:51 PM   #29311
kgrlee is offline kgrlee
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Originally Posted by Wavebourn View Post
Yes, if not to equalize properly the difference in response of front and rear capsules.
You can't fool the physics, but you can model a pressure gradient mic from 2 pressure capsules.
Yes. But you also need to provide 6dB/8ve bass boost from quite a high frequency, from above 1kHz. Have a look at the B&K info on their Sound Intensity probe. A flat response fig-8 is actually a particle velocity device though it is usually actuated by pressure-gradient.

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SM81 is one of only 2 cardioids you can buy today with flat response to 50Hz in free-field conditions. It one of the 2 most extended cardioids you can buy.
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Again, I don't see what's so special in them. Judging from datasheet, they were measured on 1 meter. You can measure mine on the same distance, and may get probably even better results.
If you send them to Cooktown, I'll be happy to check this.

Wanna make a small wager on this? Maybe a bottle of Burgundy? I'll have to ask Brad or Scott to sponsor my side of the bargain

I measured a lot of mikes in da previous millenium and even some in this. Haven't found any evidence of cardioids more extended than SM81 so yours will be the first in more than 3 decades. It will be the most extended conventional cardioid in the known universe.

Anyone used other cardioids with SM81 to record the same musical event?

Last edited by kgrlee; 15th November 2012 at 12:08 AM.
 
Old 15th November 2012, 12:04 AM   #29312
gpapag is offline gpapag  Greece
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John Curl's Blowtorch preamplifier part II
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we had like tickets printed by government from thin air.
The uncomfortable reality (current version):

We have like money, printed by central banks from thin air.




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Originally Posted by Kindhornman View Post
This is an engineers decision and the bands choice to make
Sure. (see attachment)

George
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File Type: jpg Orchestra.jpg (356.0 KB, 158 views)
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Old 15th November 2012, 12:20 AM   #29313
Wavebourn is offline Wavebourn  United States
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John Curl's Blowtorch preamplifier part II
Richard;

may be you just need to buy some bigger woofers and stop your haunt for microphones with extended bass?

I can personally mold for you a pair of boxes, but shipment of concrete through the pond is for your expenses.
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Old 15th November 2012, 12:33 AM   #29314
Esperado is offline Esperado  France
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Originally Posted by kgrlee View Post
Anyone used other cardioids with SM81 to record the same musical event?
I agree, of course about with what you wrote about Cardiod mikes. It is inherent to their principle of construction: acoustic short circuit of distant long lengths waves.
On this point of view of bass reproduction, artificial heads with omnis are OMHO better.

I don't 100% agree with your comment about ORTF miking. Yes, it depend greatly from the linearity of the mike's response curve at 60. That's why ORTF was using paired Shoeps mikes, near flat at this angle. And i do not agree, as well, with the "reduced width of musical scene".
What i don't like is more that the instruments in the stereo area are a little 'out of focus' (see what i mean ?) while well positioned.
I believe it is due to the mikes disparities, because, when you do the same effect in an artificial way (pan pot+delay) you don't suffer from the same problem.
Yes, they are not ideal for focusing the central instruments, but an other front mike can add a little presence to them.

About all (M-S) i had tried or listen to, i was always disappointed. Something not natural and near disagreeable. They are largely used in Europa for movie shootings. Movie mixing engineers used to play (stupid) with 3 desk's slides, while i was decoding them first and use the pan pots to reduce stereo image, instead. Same effect, easier.

Last edited by Esperado; 15th November 2012 at 12:57 AM.
 
Old 15th November 2012, 01:48 AM   #29315
RNMarsh is online now RNMarsh  United States
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John Curl's Blowtorch preamplifier part II
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Originally Posted by Esperado View Post
I don't 100% agree with your comment about ORTF miking. Yes, it depend greatly from the linearity of the mike's response curve at 60. That's why ORTF was using paired Shoeps mikes, near flat at this angle.
Wouldn't the response at zero/on-axis be peaked if flat at 60 degrees? [unless very small diameter] Thx-RNM
 
Old 15th November 2012, 02:44 AM   #29316
Wavebourn is offline Wavebourn  United States
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John Curl's Blowtorch preamplifier part II
SM-81 has almost uniform frequency response from any direction on 1M distance, according to the datasheet. http://www.shure.com/uploads/specifi..._specsheet.pdf
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Old 15th November 2012, 02:55 AM   #29317
Esperado is offline Esperado  France
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Wouldn't the response at zero/on-axis be peaked if flat at 60 degrees? [unless very small diameter] Thx-RNM
Schoeps MK4 have quite little diameter electrostatic cartridge.
The front response have a little elegance around 10Kz. A nice mike for acoustic guitars. :-)
I don't have directional curves, right now, but, indeed, they insist on their web site about constant directivity curves.
 
Old 15th November 2012, 02:59 AM   #29318
kgrlee is offline kgrlee
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may be you just need to buy some bigger woofers and stop your haunt for microphones with extended bass?
Thanks Wave but I designed some subs for the Bradford Computer Organs just to do 32' stops. The biggest installation was in the nave at Worcester Cathedral. At an organ recital, a 2 ton stone block was shaken off the ceiling. Fortunately no one was near.

Probably the most spectacular demo of my Powered Integrated Super Stuff.

I probably won't build this in Cooktown, but when you got speakers that do 16Hz with substantial acoustic power, you sorta want recordings that capture that.

So Mr. Marsh, I don't only design teeny speakers without bass. When we tested this for the first time, we (literally) raised the roof in the factory.

Quote:
.. linearity of the mike's response curve at 60. That's why ORTF was using paired Shoeps mikes, near flat at this angle.
While I have the greatest respect for Dip. Ing Wuttke of Schoeps & his designs (Gerzon believed only 3 companies could make the Soundfield; Calrec, Schoeps & ANother) he will be smiling at your confidence in his capsules

But as I said, its a huge subject and I would use a modified ORTF if I had to make something sound like a Soundfield from 'conventional' mikes.

Last edited by kgrlee; 15th November 2012 at 03:07 AM.
 
Old 15th November 2012, 03:05 AM   #29319
Wavebourn is offline Wavebourn  United States
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John Curl's Blowtorch preamplifier part II
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I probably won't build this in Cooktown, but when you got speakers that do 16Hz with substantial acoustic power, you sorta want recordings that capture that.
I've been there. Now I want such subs for all audio engineers who do mastering, to hear and remove that disturbing content that shakes my sofa each time somebody "pops" an air into the mic.
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Nothing in the universe is perfect. The ideal things are the ones that are most optimal. Optimization criteria, what matters. When I hear "No Compromise Design", I want to take a sledgehammer and test how impact-proof it is.
 
Old 15th November 2012, 03:18 AM   #29320
Esperado is offline Esperado  France
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he will be smiling at your confidence in his capsules
Don't know for now, but, long time ago, ORTF was testing all the mikes against very severe specifications. They had special models engraved for them with special plugs. That was a big market for Schoeps, at the time.
I had too in my studio, a very old electrostatic i beloved: SCHOEPS CLASSICS: 1953 - The CM 51
 

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