Where's the NULL

[radiorickm]

i come from an RF background, so i understand about lobes and nulls in a radiation pattern, and understand how this applies to the cardiod, figure 8 and other patterns on a mike.

what i am unsure of, is in what plane do they exist.

if you hold a cardiod dynamic mike vertically, does the null exist in the horizontal plane..

it thought this true. but then i thought about a uni-directional mike. you must speak into the TOP of it.

an example of my qustion is this.

I am trying to record a performer on stage. I would like to reduce audience noise in his microphone. So theoretically, i could hold the mike vertically and rotate it until i found the null point of the pattern. Once i know where the null is, i could just put a piece of tape on the mike oppisite the NULL (acutally in the lobe) and tell the performer to keep the tape facing him. RIGHT?

That should work great until he rotates the mike to a 90 degree angle (perpendicualr with the floor, then my theory goes out the window???)

some one point me in the right direction here

 

[Marik]

<what i am unsure of, is in what plane do they exist>

On axis--right in front of the diaphragm.

<I am trying to record a performer on stage. I would like to reduce audience noise in his microphone. So theoretically, i could hold the mike vertically and rotate it until i found the null point of the pattern. Once i know where the null is, i could just put a piece of tape on the mike oppisite the NULL (acutally in the lobe) and tell the performer to keep the tape facing him. RIGHT?>

The idea is wrong. It depends on the construction of the mic. Assuming you have a cardioid mic, the audience should see back of the capsule, and the performer--front.

<That should work great until he rotates the mike to a 90 degree angle (perpendicualr with the floor, then my theory goes out the window???)>

See above. Also, open FAQ link.

 

[radiorickm]

<what i am unsure of, is in what plane do they exist>

On axis--right in front of the diaphragm.

Sorry, but "ON AXIS" don't tell me a darn thing.

The idea is wrong. It depends on the construction of the mic. Assuming you have a cardioid mic, the audience should see back of the capsule, and the performer--front.

the capsule is round. you tell me where the front and where the back is


See above. Also, open FAQ link.
i have been thru the faq and 100's of threads....

still cant find my answer. guess i'll go to different manufactures sites

 

[BasPer]

For a handheld cardioid mic, the null line is the extension of the mic shaft. Lots of handheld mics are super or hyper cardioids though, and for those the null is a cone with the shaft in the middle. (And don't let the look of the MD421 fool you...)

 

[Richard Monroe]

Yo Radio! It sounds like you're confused about whether th mic is a side address or end address mic. Most stage mics are end address mics, as are most, but not all small diaphagm condensers. Cardioid or hypercardioid end address mics are pointed at the vocalist, with the specific position varying, and the cable connector, representing the null position, would be pointed at the audience. Of course, if the vocalist is a rapper, the capsule will be stuck in the vocalists mouth with the cable connecter or wireless module pointed at the ceiling-LOL.
With a side address mic (most studio condensers and a few dynamics and ribbons), the mic is addressed toward the side which traditionally is marked by the manufacturer's logo, a small silver or gold dot, or the heart shaped cardioid symbol. If the vocalist then rotates the mic 90 degrees, kill him.-Richie

 

[radiorickm]

hey guys...that was the exact answer i was looking for and unable to find

thanks a bunch!!