I know I should post this question in the techniques forum BUT... Close mic/room mic ?

all my rowdy friends are over here...
 
I understand close micing, in principle and room micing in principle and I understand about getting phase problems from having two close mics but having one maybe a foot farther away than the other.
 
However I do not understand doing close micing and room micing and not having a problem. I could be totally in left field but I think that I read somewhere that once you get a certain distance away... that the delay is no longer an issue. It doesn't make sense to me so I thought I'd ask.
 
Also using a close mic on an acoustic guitar and a vocal mic. I suppose good unidirectional mics would be a great helps there and an omni for a room mic.... but I really don't know... so what do you think?
 
Most of my mics are condensers, except I have a cheap ADK and an SM-57.. next mic on my list is an SM7b (price is a consideration), unless someone has a better idea and I am very much open to suggestions. I want the SM7b for vocals and expecially for harmonies to keep from building up badness by using the same condenser too many times. I guess the SM-57 would work for backup vocals....
 
Anyway, before I ramble too long... what about the close/room thing? Is there a formula for distances?
 
Thanks!
 
J
 
 

Wow. Thanks a lot guys. I understand, it makes good sense! It also helps me to understand both the importance of a good sounding room and how to utilize that good sounding room. It makes sense to have a room with good acoustics or an "alive room" for tracking and a dead or flat room for mixing... things I have been aware of but have not quite understood.
It makes sense to me now why I shoud have a sound source where I intend to play and then walk around the room to see where it sounds best and try placing the room mic there. Something Danny said in another thread too about having your speaker in a guitar cabinet at or at least closer to ear level instead of on the floor. I have always liked the tone of a tweed Champ sitting on the kitchen counter. It really does make a difference. I'm nt going to try that with a 4x12 though, laff. The tilt back legs on my CVR (Vibrolux) really make a difference to my ears when I use them. I guess I am thinking out loud about a few things but they are coming together. I learn so much here and one of the biggest things I learn is how much I don't know.
It is great to have people who know so much be so willing to share knowledge, it really helps me at least to have more confidence, and I appreciate it.

Thank you!
Julien