Let’s discuss. If seen these for the last year or so, but honestly haven’t had the opportunity to try one.
So, it looks like this is partially blocking audio that’s arriving from the rear and or sides of the mic. I’m going to presume that the pattern of the mic is directional, though it could be omnidirectional or figure of eight.
Blocking the back side of a directional mic would have little effect; some, but little, because the mic isn’t sensitive on that side. If tests were done with a mic in omni or figure of eight pattern, I would expect the outcome to be more dramatic.
Blocking from the side makes more sense, depending on the pattern, because it would actually be keeping sound from the sensitive part of the mic’s pattern. For the above reasons, I think you have to look (listen) hard when thinking about the specific pattern of the particular mic to be used here. The devices may make a wide cardioid less wide. But, what if you had a mic with a tighter cardioid pattern? How much would that eliminate the need of the device?
In most normal environments, reflected sound arrives at the mic from may different angles; vertical, diagonal, horizontal and everywhere in between. In live music and in some recordings, you have instruments and amps all playing at the same time. Rudy Van Gelder is an apparent master at recording jazz combos. He relies on mic placement, specifically, careful placement of directional mics to craft his sound stage. Would these devices help him? Hard to say.
I do know that a well-positioned figure of eight mic can null the bejeebers out of nearby sound, just by being positioned to do so.
It sort of comes back to the application. What are you recording? Where are you recording it? Why are you recording it there?
Let’s see what we can discover. Let me make a few calls..
Regards,
Ty Ford
Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Watch Ty play guitar