DC Offset

It's a big non-issue, because DC offset isn't usually a problem in a recording context. Certainly not at -96dB or -130dB.
 
If you regularly see significant DC offset it's an indication of some faulty hardware, perhaps a preamp or the audio interface. You'll not see it with sampled or synthesized sounds. And even if a small offset is present, it's not necessarily a problem. You won't hear it, and it doesn't hurt anything. The only effect it'll have is a trivially slight loss of headroom.
 
Also, DC measurements are often misleading because the software can't distinguish between DC and very low frequencies. Some of the "DC offset" you're seeing could in fact be subsonic rumble, which can't be heard but can be sensed by your dynamics processors. This is why we place a HPF on the master bus, in front of any buss compressor or limiter.
 

If you have an application like Adobe Audition it is very easy to measure the DC offset with an Amplitude Analysis process.
 
If you have modern AtoD gear that has a well designed power supply it will be a trivial issue.
 
I usually see something like 0.010% DC offset on my mixes.
 
You can clear out the offset with a "Repair DC offset" process in Adobe Audition.
 
I imagine every other good audio app has similar functionality.
 
IIRC Sonar's remove DC offset function applies offset removal to the input AS it is being recorded.
 
This is effective because DC offset primarily occurs in analog gear, all of which has a DC power rail that the AC (your sound signal) floats upon. As Bitflipper has suggested, the wide band capability of ITB mixing allows the lowest frequencies to mimic the symptoms of DC offset and so it may seem as if the mixing process adds DC offset... but it's not likely to actually be DC... just incredibly slow AC. There isn't much DC processing going on in sound signal DSP unless perhaps someone is *modeling* a vintage Quadraverb or something skanky like that.
 
You can easily minimize that with the High Pass Filtering that Bitflipper recommended and you can simply make it go away with a subsequent "Repair DC offset" process.
 
If you have good gear, it's a trivial issue... but if you enjoy good housekeeping you may make it a non issue very easily.
 
I think the answer to your specific question is that it's safe to wait till the end of the production process to do it. You don't need to work on each track.
 
I've never seen bad DC offset in my work. I have seen significant amounts of it in other people's work. (I like to look and see what folks are doing) I think if I felt that my source tracks had a bunch of it that I'd process the tracks, but it never seems to be an issue.
 
Check your stuff and see how you feel about it. My guess is that you'll find you have a trivial amount and the removal process will mainly be an act of good housekeeping.
 
best regards,
mike
 
 
 
 
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Well I found it informative.

Cool. Thanks everyone! Bit, your statement is backed up by the fact that the -96 dB was on the bass track. so, on guitar and vocals I was at -130, it is probable that the -96 was only because I was recording the bass itself. I had originally guessed that it had to do with the fact that I took a direct line from the bass amp.