Agreed with most everything above.
Best in good sounding spaces where a relaxed natural sounding recording with full frequency range works well. Great outdoors when the sound is clear. Outstanding for acoustic / classical music in dedicated halls. Stagelip/onstage almost always works, farther back the quality of room and patrons becomes more influential on the result.
Hard to beat combined with directional mics (or SBD) - can lean harder on the omnis when the acoustics allow, more strongly on the directionals when needed, but almost always end up including at least a bit of both as they tend to complement the each other well and address the other's deficiencies. Provides good bottom extension, 3d "air" and naturalness the directionals often lack on their own. For that reason I run them for everything along with directional mics, even in situations where omnis would ordinarily not be a go-to choice. When it works they are the foundation and often the largest contributor to my mic mix. Omnis in combination with a highly directional pair in the center provides an overall collective pickup pattern similar to wide-cards, variable to taste via mix ratio. The situations in which I tend to use the least from them are small clubs from a recording position midway back in the audience or from the SBD, in which case they might only contribute a little, and on some occasions none at all. I don't tend to like those situations, but its a good option to have.
They tend to sound more relaxed, and less "up front and direct" than directional mics. They take EQ well and a bit of a midrange bump can enhance the sense of proximity and clarity when used on their own, similar to what combining with a directional pair does. If EQing you can manipulate excessive bottom as necessary.
Spacing: 2 feet is my minimum. 3 feet is a good go to and almost always works well. Used in combination with a directional pair in the middle try for 4 feet, 5-6 feet even better great If you can arrange for it. Sufficient spacing improves the feel of the recording and quality of the bass. Good to increase width when recording from farther away. Sufficient width also helps diffuse the portrayal of nearby audience pickup, but as Aaron mentions, hoisting high is usually the best way to deal with audience noise. Classical and studio situations will recommend less spacing, but there's a magic from sufficient omni spacing for live concert taping.
Angling: Why not? Use that little bit of top end directionally they have to advantage. With very tiny lavs it won't matter, but with standard pencil mics it can.
Topic: best kinda room for omini's (Read 485 times)