Preface: A few months ago I found an amazing device I should have found years ago â€” the amazing Zoom H2. Appropriately dubbed "a studio on a stick", it can produce amazing sounding location recordings. In the right hands, of course.
By "mastering" such a recording I mean simply making it listenable and enjoyable. The process is different from a conventional mix. On one hand, the material is taken care of and, if you're lucky enough to be listening to great musicians, already sounds very good. On the other hand, the only things you can really control is the mic position and your input gain level. Your task in post production, therefore, becomes correcting the things you could not change earlier.
This is a big one. During a performance levels can fluctuate wildly between sets, individual songs, solo sections, etc.. This works great when you are part of the setting, but listening to such a recording would be rather difficult, especially in less than ideal environment such as a car. You would have to keep adjusting the volume to hear the quiet parts over the noise and to keep the loud parts from blasting your ears.
We can avoid that by preemptively doing it for the listener: with volume automation curves and compressors. But take care not to destroy the dynamics entirely â€” the level changes must be subtle enough to keep the quiet parts perceptibly quiet and loud parts loud. Just enough to make the whole thing intelligible at a moderate and constant level.
To throw in a video analogy, there are webcams that show a static frame with a person moving about and then there are some webcams that constantly follow your face and fill the screen with it. You have to play the camera operator, zooming in and out when appropriate to produce a smooth and transparent viewing experience that does not get in the way of the story.
My processing chain
There is a gain plugin set to +6.8dB to bring the recording into a more useable range. The rest is just volume automation, some of it done riding a fader, but mostly just mouse drawing. I briefly toyed with a compressor but could not get it to sound right to my ears.
The order of EQ and compression still puzzles me, but this placement is logical: it is there to correct the room/mic response. Where I was sitting it picked up hardly any bass and there was a pronounced honk around 400Hz. Also, I was very close to the drummer and the cymbals are just way too overpowering most of the time, so everything above 2.7kHz comes down about 5dB to keep them under control.
Tricky to operate and very easy to make a total mess of your sound. I started off with a "Slow Attack 4-Band" preset and played with it to add some punch below 40Hz and to control the cymbals a bit more.
Two of them, sharing the gain increase. They seem to adapt better this way.