Strange Device - Microphone Collar?

[Jack Hammer]

Last night I saw a live Salsa band playing in a club. They had five horn players, three trumpets and two tenor saxaphones. the mics for the trumpets for 57s but here is the strange thing, they seened to have a sort of round, clear plastic collar device apparently to prevent either feedback of leakage. I am wondering if anyone has ever seen or used such a thing and whether or not they are effective.

By the way, there were many percussion instruments on stage and thus the idea of preventing all of the percussion from leaking into the trumpet mics makes some sense. ther eason I find it strange is becuase I though SM547s were omnidirectional in the first place. If this is so, what good would the "collar" do?

 

[littledog]

Ha ha! Good guesses, but you don't get the prize!

The plexiglass shields around the mics have nothing to do with the sound system or the mics - what they are for is so the horn players can hear their own instruments better - the sound reflects off the plexiglass and comes back to their ears. This means that there can be less horn volume in the stage monitors, reducing the ambient stage mud.

Horn players love them. (Ever notice a horn player practicing by playing right into a wall? Same idea.) The trumpet player and trombone player in my band have been using them for years. Now they won't play without them. Obviously it doesn't work for woodwinds like it does for brass.

And by the way, 57's are cardioid, not omni.