Keep in mind it's not a system directly geared for recording, but rather Mastering. My advice is keep the meters busy, but no reds in the DAW or A/D converter. Only reds are occasionally OK on fully analog mic-pre's and that's only for kick or snare. Nothing else should give you a red LED. Best of luck!
This is very incorrect. It relates definitely to recording as well as mastering. It applies to tracks and busses and your final mix buss as well. I use the K system during all stages of a production. It does require the use of VU meters though either real or virtual. When you apply the K system during all production stages you end up with your rms levels being constant on tracks and busses. No clipping anywhere.
There is nothing random about recording levels on tracks for example.
eg just keep the meters moving and watch out for red clipping lights. You can apply the K system to tracks and when it is time to mix you will find you have got extremely consistent levels on your tracks and you never have to add or subtract gain anywhere in order to make a sound be heard within a mix.
In fact it does not apply to mastering so much because your final master will end up being louder than even the highest K -12 level. The principles apply but in a mastering situation you are dealing with a higher K system level such as K-7 for example. In mastering you are aiming for that higher level but it is more so about consistency of average rms levels in your mastered album tracks.
The VU meters are required because Sonar and many other DAW's do not display
rms levels very well.
(Studio One can however show rms levels at full scale) On most DAW's the
rms levels are way too far down on the scale for them to be useful. Sonar also shows the
rms level to be 3 dB lower than it should be also. Something to keep in mind.
The VU meter shows full scale (O dB VU) while the system is actually operating at the K level underneath. eg K-14 or K-20 etc.. The basic concept is that your whole system is operating well below 0dB FS and hence will sound fantastic as a result. There is also lots of headroom above
(12, 14 or 20 dB to be exact) the normal operating level such as it was in the analog days. There is no need to be that close to 0 dB FS anywhere. It is only in mastering that we get things louder and up closer to this level. And wouldn't it be nice if we did not have to do that at all and stay at the ref level.
K system is also about calibrating the SPL level of your monitoring at all K system levels. Important.