I have some experience with this. Several factors will determine the best distance. If the room in which you're recording isn't too live (i.e. has very few, if any, smooth, flat surfaces, such as walls, windows and floors), and the sound doesn't bounce, it is a good idea to put the microphone a good distance away from the face. Usually, some 30-50cm (about 12-16 inches). When the microphone is close to the face, any slight movement can cause swings in audio level. In addition, microphone will more prominently pick up unwanted sounds, such as lip smacks, breath taking, pops from 'b', 'p' and 't' sounds, sibilance from 's' and 'z' sounds, etc. Having it far enough reduces those, as well as evens out the frequency response. This also makes it possible to record voice without the pop screen. As good as these are, they can muffle some of the highest frequencies.

If the room has too many smooth surfaces and the sound reverberates and/or echoes around, it will be difficult to capture raw, direct sound unless the microphone is very close. In that case, the talent must be careful not to move around much (or at all), and it will be very necessary to use pop screen to avoid serious unwanted pops from those 'p' sounds.

One remaining significant consideration is the actual sound quality of the voice. Putting the microphone close will enhance the 'proximity effect', which noticeably enhances lower frequencies (i.e. below 200 Hz). If the voice is male, this may, in some situations, sound desirable. On the other hand, the same effect can easily be obtained with proper use of EQ. Meanwhile, it is easier to control the audio quality and levels if the microphone is placed at some distance.

Bottom line: whenever I can, I put the mike at about 50cm (16 inches) away from the speaker, approximately at the height of his/her forehead. If it is a studio mic shaped like Neumann U-87 (side-address), I'll hang it from the stand on the shock mount and point it downwards. That way, the stream of air projected from the speaker's mouth doesn't go directly at the microphone, but the mic still picks up the voice very clearly and directly.

As for the level of background music, there is no dB rule, primarily because the objective level of that audio will depend on the actual music track. If the music was written and arranged/orchestrated to be played over spoken voice (male or female), the arranger/orchestrator will have likely taken care to leave some free sonic space within the frequency range of base frequencies of the voice (an octave below middle C for male, or above, for female voice). If the music in the background is some ordinary instrumental, it will likely contain instrument(s) that will fight for that sonic space with the voice, and the whole track would therefore have to be silenced to the point that it does not interfere with the intelligibility of that spoken voice. Even worse if it is a song that someone sings.

When the final audio mix is done, it must be done in optimal conditions (good monitor speakers, good room), so that proper optimal balance between various tracks can be made.

Thanks. Now I forgot about paying attention to all the other sounds in a room. I want to record in my room which is next to a window. I really don't have a choice to move anything around but next to another window.
So last night and this am I put a few clips together and began speaking ... trying out different distances. It appears under the circumstances I have to be fairly close to the mic. I am using a blue mic Yeti.
I didn't realize I had congestion believe it or not until I heard my voice playback. I guess I have the lingerings of a cold that suddenly became quite clear to me. In the meantime I was fooling around with the music dbs and background sounds (crashing waves) as I spoke. I haven't found a happy medium yet.

The more I learn the more I realize how detailed every aspect of filming is. I used to think that voice over was just talking but without realizing all the details that go into it...everything from making sure you don't have congestion!

So it looks like its going to be a while before I find that happy place.

If you have ANY possible means to move things in that room, I would suggest a few things that would make recording voice a bit better:

1. If there are curtain rods on those windows, hang some heavier curtains (or blankets, or other cloth or canvas that's a bit thicker than ordinary thin curtains or venetian blinds);
2. If you can afford it, get a couple of cheap Chinese screens (tri- or quad-fold) and create a little booth around your microphone. Hang some beach towels on the inside of those screens;
3. Get a solid good night's sleep before recording. Nothing sounds more natural than a well-rested voice.

Essentially the principal idea is to dampen the echo/reverberation in that room. There were several situations when I needed to record vocals or softer wind instruments in an ordinary room, in an apartment building in Manhattan. I used something like these:

http://www.amazon.com/gp/product/B0014ZWKDK

With a bit of luck, you can improve the room acoustics significantly.

You should check out these websites:

SOUND LINKS ? http://realfilmcareer.com/forum/index.php?topic=14.0

http://jwsound.net/SMF/index.php

http://www.coffeyinteractive.com/phpbb2/ramps.php - RAMPS, Sound Newsgroup

http://www.coffeyinteractive.com - Sound Forum

http://audiotuts.com/mixing-mastering/how-to-process-vocals-for-an-amazing-professional-sound - How to Process for an Amazing Professional Sound

Brian Dzyak
Cameraman/Author
IATSE Local 600, SOC
http://www.whatireallywanttodo.com
http://www.realfilmcareer.com

I actually have those room dividers you are talking (writing) about. Never thought of that. I can certainly buy some thick velvety type curtins from a local store here really cheap.
Clear up the sinus.
I am collecting all this footage I have and trying to put it together while practicing this vo. Right now I am not in a rush to have it done until spring/early summer. But since I am so green at this I need all the time I can get..and also I work.

So far I have also learned not to talk when a sufer is crashing...the sound of the waves was so powerful and my voice talking about it just took it away.

in terms of balancing the voice over and the music, you should record the voice by itself in a quiet environment, yes 2-4 inches from the mic

and then import that music onto a separate track and mix the two tracks (voice and music) together in your software

this way you can optimize the voice by applying eq and compression, etc without affecting the music track and you can achieve the perfect balance ... while its good to experiment, you should never record the voice and music at the same time, its inefficient because you can't change the mix once the recording is done and you may end up doing a dozen recordings instead of doing them separately once and then mixing afterwards

SFXsource.com Sound Effects and Royalty Free Music
http://www.sfxsource.com
http://www.freesoundeffectsandlooops.com

Okay. So do the voice and add background music later.