Sometimes it seems that the microphone world revolves around the cardioid polar pattern. Life is easy when you’re the most popular belle at the ball! But omnis have a lot to bring to the party too.
For one thing, they don’t suffer from proximity effect, so with an omnidirectional mic what you hear in the room is what you get with no low end hype from the mic. Their lack of a directional polar pattern also means you don’t need to worry about the microphone not being aimed properly at the source, so it’s perfect for picking up a round robin of voices or instruments. That lack of proximity effect and directionality also means that there’s much reduced impact from plosives (bassy thumps from “P,” “M,” and “B” sounds).
The next time you’re looking for a natural-sounding recording with good room ambience, grab an omni and get to work!