I think I've learned the basics of the K-System, though I haven't yet had a chance to use it for real.
 
Say you chose -20db for reference.  I understand that you try to get your input tracks to be around that and may adjust with the gain knob before going any further.
 
For a recording done outside Sonar, would it make sense to normalize the wav file to -20 by using something like Audacity of Audition before importing the file into Sonar ?  Or does it not make any difference ?  Does normalizing do anything different than the gain control ?
 
My thinking is if I'm going to try to maintain -20 throughout, I might as well start there as well.
 

Be wary the K-System refers to the average volume level at 83dB SPL at the 0 decibel point. The K System was developed by Bob Katz as an alternative to the varying RMS measurement standards.
 
Let me explain, the K-20 reference was designed for classical,soundtrack and music without a lot of loud transients like you get in dance music or rock music. So the -20dB refers to the average volume level at any given time rather than the instantaneous VU reading. 
 
When you refer to the meters using the K-system when the bars cross the 0 point, this is where it's exceedig -20dB RMS. However if your VU meter may be peaking at -3dB which is a tell-tale sign of lack of dynamic boost in your overall mix. It also allows you to judge the VU volume and RMS in the same place.  So adjusting the EQ or volume of a certain track might be enough to fix that. Limiting should be last thing on the agenda.
 
I'm rubbish at explaining things however I hope that helps.
 
Personally I never normalise sounds unless it's a final product not mid-project. 
 

With the K system it is important to use proper VU meters rather than the DAW meters. The DAW meters won't tell you much and the rms readings are so low it is much harder to read. Also Sonar rms meters show the rms reading as being 3dB lower than where they should be which is also not good.
 
There are VU meter plugins of course and what you do is calibrate them so an rms signal down at -20 makes the VU meter show 0 dB VU. (note a correct rms level of -20 rms will show as -23 rms in Sonar, unless this has been fixed in X3 of course!)
 
Normalizing is not the way to go either. That process looks at peaks not rms levels so it is useless. (unless you can do rms normalization but I still would not do that) What I do whan a project is tracked outside of my main DAW is open the tracks up in an editor program one by one and take an rms reading of each track. Some tracks will be louder than 0 dB VU so I might drop them down by that amount. Other tracks may fall short of 0 dB VU so I usually add gain to those tracks to get them back up to 0 dB VU.
 
You can also do this by importing the tracks into your main DAW and setup an rms VU meter over them and take some readings. Then adjust the gain so all the tracks are showing the same rms reading. Make sure you make a complete backup of the whole session before you do any permanent changes to gains etc...
 
It is a good idea especially for sessions recorded outside your main DAW to adjust all the tracks so they are all around -20 dB rms (or 0 db VU) then the mixing process will be much easier.

I don't normalize tracks outside of Sonar.
I prefer the gain nobs to strict 'normalization' using process > audio > Normalize.
 
I do use process > audio > normalize sometimes. This does not normalize to RMS or VU. It normalizes to peak.
 
 
 

Jeff Evans
Normalizing is not the way to go either. That process looks at peaks not rms levels so it is useless.

Ok, this I hadn't thought of.  I have the Klanghelm meters so I'm ok within Sonar.  I was just thinking that if I wanted to use -20 (for example) and keep things there throughout, I might as well start with a track that is already at -20.  But I didn't realise normalizing looks at peaks, not rms (actually I knew it, I just didn't think).
 
So I'll use the gain knob and my meters.
 
Thanks.
 

all it does is move the waves up to where the peaks all hit the same spot (that you dictate, all the way up to 0db)
 
it does not provide any advantage at all,
except to bring up the noise floor; if there is noise on your tracks at low level,
it brings that up too.

http://www.meterplugs.com/kmeter
 
Watch the Freemasons video. Makes interesting viewing.
 

"Normalization" has a broader definition than just raising everything until the highest peak is at some target level. Broadly, it means to make things conform to some standard. You can normalize to any target: peak, RMS, LUFS, K-20 or any other reference you like. 
 
Whether it's worthwhile pre-normalizing files prior to mixing is another question. It could be a time-saver as Jeff suggests, but it depends on how wildly off they are. If they're all reasonably in the ballpark, I wouldn't bother. It's not that hard to normalize within the DAW if that turns out to be necessary.

I have just recently mixed a track that was tracked elsewhere.  Some of the tracks were 15 db too low in level others were 3 dB too low.  Some were 4 dB too high.  (makes you wonder how people actually track stuff, badly folks)  I believe it is well worth making all of them the same rms value (in my case I was working at K-14 for this project)
 
Even the tracks that are 3 db too low.  It still all helps.  It just means now most of your faders are around unity in order to achieve nice buss levels etc..  You never have to add in plugins to add gain etc..  You don't have to turn down very loud tracks.  They are just all at the perfect level ready for a mix.
 
I was measuring rms values using a VU meter also.  Bringing up tracks even by as much as 15 db rarely makes the noise audible either.  If a track was tracked down at say -30 db it means the noise is more than likely still 50 to 60 db below that.  Yes adding 15 db of gain to a track raises everything but in most cases you still wont hear the noise.  Instead you have got a track that is now at the right level rms wise.   That is far more important.

interpolated
http://www.meterplugs.com/kmeter
 
Watch the Freemasons video. Makes interesting viewing.
 

Watch out using bar graph meters for showing you rms levels. A VU gives you something else apart from the rms level.  And that is the ballistic.  ie how the needle dances to the music.  There is much to be gained from learning how to read that.  Bar graph meters don't show it anywhere nearly as well.
 
Real VU's do it the best in terms of ballistics but I must say the VST's are getting very good.  The Klanghelm meter has got a very good ballistic.  I have devised some special tests for showing VU ballistics and some VST's just dont cut it especially in how they fall back.  But the Klanghelm meter is excellent.  Not perfect but damn close.  Also PSP has released a nice VST as well. (Triple meter) and the ballistics have improved in the VU meter I am sure of it.