anonymous
11 April 2002
I am having a little trouble understanding the cancelling of high frequencies due to closeness of directional mics to the sound source. what's the relation between high freq and it's wavelenghts coming from 0 degrees cancelling at the mic diaphragm? and why does the dual capsule omni mode exhibit so little effect? I know single capsule omnis don't at all.any help will be much appreciated.Thanks
Comments
Hi! This is very basic , so forgive all the missing details..
Hi!
This is very basic , so forgive all the missing details..
It's not canceling the highs; it's increasing the low frequency with proximity effect. I think you are referring to figure 8 setting as dual mono?
(I could be way off here thinking that, if so, let me know), the figure 8 setting is designed to cancel at the sides, not the rear as in cardioid designs, which give the effect that you describe because some sound is allowed to reach the back of the capsule through a small opening. At close distance, the mic itself becomes an obstacle to the high frequencies at the rear, where the bass will wrap around and enter the port at the rear increasing the low end. Some mics have a roll-off to help flatten the response back out, and some like EV RE-20, or PL-20 have variable roll off as you get closer.
Hope this helps,
--Rick