It is important to distinguish between peak and rms values of any signal. To get gain staging correct you need to know about both, not just one. Most DAW's provide good peak indication devices but are poor in the rms area. You need VU meters to show rms values more readily. Real ones are best but if you cannot get them or use them there are some great plug in alternatives.
We know that in order to avoid clipping and getting too close to 0dB FS we need to work at some ref level down from that. K system suggests 3 ref levels -12, -14 and -20 db FS. What ever you choose as a ref level you need the VU meter to show 0 dB VU when the rms signal is down at the ref level. This is where any rms indicators that DAW's provide are useless. Because if you are down at say -20 db then the rms level is very low on the meter scale (in Sonar case 3 db even lower than that) hence they are hard to read down so low on a meter scale.
If you track correctly at your ref level using a VU meter then all your tracks are already at the correct rms levels. If not you can check each track one by one with the VU to see where it sits in relation to your chosen ref level. Use your trim controls to either add or subtract gain accordingly.
The loudest parts of the song should only just reach 0dB VU either on the buses or the masterbuss. You can still get the perfect mix and get your buses just hitting 0dB VU and your masterbuss also just hitting 0dB VU on the loudest parts of the music. Softer sections will drop below that but they are supposed to.
If you work this way you will have perfect consistency level wise between all your songs and mastering is also much easier as well. Also you will never even come close to clipping 0dB FS
(anywhere on tracks or buses) because of the headroom that you have built in by choosing the K system ref level that you have.
(Note: you can still clip plugins peak wise on tracks and buses and still maintain a correct rms level so use the input and output controls on your plugins to avoid peak clipping and fine tune for correct rms levels) I work at either K-14 for a lot of general work and K-20 for the highest quality and most transient sound. Both have their merits. K-14 means less push up level wise during the mastering stage to reach the final mastered loud rms level. K-20 just means you have got further to come up to achieve the same final mastered level. But it also means you have got this beautiful pristine transient version of your mix with 20 dB of headroom if you ever need to go backwards to that.
You see peak indicators are great at keeping peak levels consistent on tracks and busses and that is what most of you are doing, but your rms levels are all over the place. That is why people have problems with gain staging and levels getting out of control. VU meters keep rms levels consistent on tracks and busses and the peak levels are varying. This is how it was with analog in the old days. We did not worry about peaks because the headroom built into all the analog stages took care of the peaks. But with digital we have obsessed about peaks (rightly so too) and dropped the VU meter in favour of peak indicators. You really need both. Using a K system approach also takes care of the peaks due to the headroom we decide to use in choosing our ref level.
The secret to perfect gain staging is using VU meters. Without them you are floundering in the dark. Most people don't use them and that is why most are floundering in the dark not getting their gain staging correct, clipping tracks and busses everywhere and wondering why their levels are all over the place. If you get a good result without them, you are only doing it by luck. As I have said many times all serious mixing consoles have them and so does every mastering engineer worth their salt as well.
K system is also about consistent monitoring levels in your control room at the chosen ref level. I like using 85 dB SPL.
(C weighting, music too NOT pink noise!) Some say that is too loud but I disagree. I think it is a great volume. And a volume where the ear is at its best
(if you can call it that) frequency response wise. If you monitor for
too long either above or below 85 dB SPL you will be making incorrect mix decisions.
There are plugins that can do great VU metering. BlueCat meter is very good.
http://www.bluecataudio.com/Products/Product_DPeakMeterPro/ There are some free ones too but they don't look like a normal VU meter but the bar graph concept as per the BlueCat. But the BlueCat is a classy display though.
But if you want a VST that looks like a real VU meter the Klanghelm meters are also excellent.
http://www.klanghelm.com/VUMT.html The Klang meters are cheap and they can be set for a very accurate representation of a real VU ballistic. The settings are not like that standard, I have done some extensive testing and got the perfect settings that set up a ballistic very similar to my real VU's which are expensive and very very good.
Many of you are getting great results and mixes without VU meters that is for sure, but if you got into them and really started using them your results would be even better, that is what I believe anyway. Because I am old I have come from the analog era with lots of VU's into the digital era but I have still maintained the use of VU's right through both systems and because of it some aspects of my production just have not changed at all from analog to digital and maintained an amazing sense of consistency. But in other aspects digital is way better, no noise and great transients that analog just could never produce as well.
Sorry for the long post, it is almost as long as a
Danny post LOL!
But then again I don't think I could ever out do
Danny in that respect!