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Can a mic lose directivity with increasing distance??? Multi-Ef­fects Plugins
Old 14th September 2011
  #1
Gear Nut
 
Joekkel's Avatar
 

Can a mic lose directivity with increasing distance???

i found a really confusing statement considering the shure ksm44 on this blog:

Shure KSM 44 Microphone


"One downside to the KSM44 is that it isn't much of a distance mic. One of the Shure engineers warned me that programmable polarity microphones are inclined to lose their directivity after 2-3' and that is certainly the case with the KSM44. However, several of the microphones we used in comparison were less inclined to exhibit this tendency at normal studio distances than the KSM44. For example, Studio Projects' B3 hung on to it's cardioid characteristics at almost double the KSM44's mic'ing distance. The same was true for the bidirectional pattern. AKG's 414 and the Neumann U87 were also more directional at distance than the 44."

i'm wondering: why should a mic lose it's directivity with distance?? it may lose lowend due to the proximity-effect...but directivity? this statment would mean, you can't record orchestras in cardiod with ksm44, caus it will be omni either way

imho, the author of the quoted text wrote some serious garbage. or shall i be corrected?
Old 14th September 2011
  #2
Gear Head
 

Nope, it's a crap statement.
Old 14th September 2011
  #3
Lives for gear
 
frans's Avatar
Words. Use them wisely.

Ignoring the link I can say that much... back off the mic and it hears more room (the source heard from ALL directions + reflections + the phase relationships of all signals involved). You could call that "losing directivity". But I think the message just means that the directivity-fluid* drips from these little holes in the mic... so get a piece of toilet paper ready to clean up the mess. Maybe that mic just isn't housetrained.

* flux compensator taken into account
Old 14th September 2011
  #4
Gear Head
 

New product idea - The Mic Diaper.
Old 14th September 2011
  #5
Gear Nut
 
Joekkel's Avatar
 

whoa, the quality of directivity-fluid is so underestimated. heard, that chinese mics use poor qualitiy-fluids, hence the lack of mojo...



thx, thought it was a crap-statement
Old 14th September 2011
  #6
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frans's Avatar
Quote:
Originally Posted by ToxicAvenger69 View Post
New product idea - The Mic Diaper.
Only valid if the sh-t nulls.
Old 14th September 2011
  #7
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audiogeek's Avatar
 

Quote:
Originally Posted by Joekkel View Post
i found a really confusing statement considering the shure ksm44 on this blog:

Shure KSM 44 Microphone


"One downside to the KSM44 is that it isn't much of a distance mic. One of the Shure engineers warned me that programmable polarity microphones are inclined to lose their directivity after 2-3' and that is certainly the case with the KSM44. However, several of the microphones we used in comparison were less inclined to exhibit this tendency at normal studio distances than the KSM44. For example, Studio Projects' B3 hung on to it's cardioid characteristics at almost double the KSM44's mic'ing distance. The same was true for the bidirectional pattern. AKG's 414 and the Neumann U87 were also more directional at distance than the 44."

i'm wondering: why should a mic lose it's directivity with distance?? it may lose lowend due to the proximity-effect...but directivity? this statment would mean, you can't record orchestras in cardiod with ksm44, caus it will be omni either way

imho, the author of the quoted text wrote some serious garbage. or shall i be corrected?
I don't even know what that quote is saying. I mean... Is he just saying that the "on-axis" properties of a KSM44 are wider than that of a 414 or a U87? Not sure I understand.
Old 14th September 2011
  #8
Lives for gear
 

Yes, directivity of dual diaphragm mikes does change at some frequencies and distances.

Review Torio and Segota:

http://www.shure.com/idc/groups/publ...hragm_mics.pdf

Note that the low-pass portion of the transfer function tends toward omni for a model dual-diaphragm mike. Translation, moving from 2 feet out to 8 feet, the dual-diaphragm capsule in cardioid mode stays cardioid at 1K, but starts to go omni at 100 Hz.

Obviously, the details of a real mike matter. The KSM 44 may have a stronger propensity to go omni at low frequency in cardioid than other dual-diaphragm mikes.

Face it, cardioid mikes are messy. It's in the nature of a mike with sound entering from the back side as well as the front, but through a complex acoustic resistance that produces a complex response.

Cheers,

Otto
Old 14th September 2011
  #9
Gear Nut
 
Joekkel's Avatar
 

wow otto, thank you this input! so it's obviously no garbage... always good to learn something new.

cheers
Old 14th September 2011
  #10
Lives for gear
 

Quote:
Originally Posted by Joekkel View Post
wow otto, thank you this input! so it's obviously no garbage... always good to learn something new.

cheers
You're welcome. Over the decades, I've found that the more I understand the physics and engineering of real microphones and their deviations from "ideal" models of performance, the greater the miracle it seems to me that we can actually use all this stuff to make recordings that sound good and may even present an illusion that smacks of real sound.

Cheers,

Otto
Old 15th September 2011
  #11
Gear Head
 

Quote:
Originally Posted by Joekkel View Post
wow otto, thank you this input! so it's obviously no garbage... always good to learn something new.
cheers
I'd contend it's still a garbage statement, at least very poorly worded.
Old 15th September 2011
  #12
Gear Addict
My explanation would be that the mics that "stayed cardioid longer" are the ones with peakier high end. This gives an impression of greater detail, and the normal tendency for an LD to become more directional at higher frequencies gets a boost with these brighter mics. The phenomenon is similar to the use of diffuse field omnis for more distant placement.

Fran
Old 15th September 2011
  #13
Lives for gear
 

Quote:
Originally Posted by ToxicAvenger69 View Post
I'd contend it's still a garbage statement, at least very poorly worded.
The comment attributed to the Shure engineer regarding dual-diaphragm mikes becoming less directional at larger distance (at least at lower frequencies) is correct, flows from their analysis and is confirmed by experiment. The other comment about the KSM 44 relative to other mikes is not supported by any meaningful measurements documented on the referenced blog. I'm skeptical of any such claim without measurements to confirm it, but recognize that such model to model differences might exist to some degree.

Cheers,

Otto
Old 15th September 2011
  #14
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audiogeek's Avatar
 

Quote:
Originally Posted by ToxicAvenger69 View Post
I'd contend it's still a garbage statement, at least very poorly worded.
+1
Old 15th September 2011
  #15
shure ksm 44 definitely loses some of the sound if positioned far from source, i used it for 3 years along with a u87, u can place the u87 2 meters a way in cardioid and still pick a good sound, thats not the case with the ksm 44, but it doesn't mean it is a bad mic, it is a great mic, worths every penny.
Old 15th September 2011
  #16
Registered User
I suggest that any mono mic has already lost all sense of direction ...
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