mic patterns vs feedback

[jagpunk]

What is the relationship between the different mic patterns and the feedback that each mic creates?

To be more specific, do mics give feedback in different positions according to its pattern type? If so, what is the rule of thumb for mic positioning for each pattern type?

 

[Tuner]

Yes, mics can often feedback depending on their pickup pattern and the location of any loud sound sources. This is very important in a live situation.
A mic with a cardiod pattern (eg SM58) picks very little noise from the 'back' of the mic, ie the end where you connect the cable. So in this situation you should place your monitors directly in front of you and behind the mic.
A mic with hyper or super cardiod pattern picks up significantly more sound 'behind' the mic in order to have a tighter pickup from the front or singing end. In this case your monitors should be set up at 45degree angles to the microphone.
It's very late now, sorry if this turns up to be a load of garbage

 

[jagpunk]

no, thanks... your post WAS helpful

 

[vox]

Generally mics feedback at the frequencies that they are most sensitive to, if you look at the frequency response graph of for example an SM58 you will see that it has a boost at around 5 khz, this is usually the first frequency to start feeding back. The pickup pattern of a mic tells you how sensitive it is to certain frequencies that hit the mic from different angles, eg. from behind.