Okay. Do you understand absolute value in mathematics? 

How far am I away from 0?

The absolute value of any number is that number. 

-14 is 14 units away from 0
28 is 28 units away from 0

Headroom is just that. However, to use the above numbers relating to volume: 28dB is atrocious distortion. -14dB - how about we creep that up a bit?

This is the reason he said K-20 has the most dynamic range because 20 is further away from 0 than the other two values (in both directions).

K-20: 20dB of headroom
K-14: 14dB of headroom
K-12: 12dB of headroom

What Bit did was calculate the difference between the real scale and the K-Meter's scale to get the headroom capacity. 

If your master is @ -6dB, yes, you have 6dB of headroom according to the real scale (the VU meter value). However, if you figure in the different K-Meter scales:

K-20 @ -6dB = 14dB
K-14 @ -6dB = 8dB
K-12 @ -6dB = 6dB

Notice the headroom decrease.

That may be the wrong analogy to use, but I did to illustrate the YT video and Bit's summation. (Do correct me if I am wrong)

The important thing to remember is when you are working normally ie mixing you can work with K system reference levels eg K-12, K-14 and K-20. But when you are mastering you have to alter the calibration of your system. You cannot use normal K metering to master while the ref level is set for mixing.

The meters in that K video are not great either and I would not recommend them. You are better off getting a VU meter that looks and operates like a real VU meter such as the Klanghelm meters here:

http://www.klanghelm.com/VUMT.html

The reason is that a VU meter needs 300 ms to reach the 0 Vu dB mark on the scale so therefore it is not responding much to material that is faster than that. Hence it is much better at showing you the true rms value of the signal. A VU makes it much easier to set tracking levels and buss levels.

Back to mastering. Suppose you set up a K ref of K -14 but import a well mastered commercial CD. What you will see then is the VU meter going well off the scale so to properly master you must be able to re calibrate the K meters. I have found a lot of loud commercial material is around -7 dB rms so you really need to be able to quickly and easily reset your K metering to suit eg the K meters have to be set now for K -7. The Klanghelm meters allow to calibrate at any ref level which is better than the meters in that video as well. With real VU meters such as I have I have a variable amplifier driving them and I can easily alter the ref level as well.

So if you recalibrate to say K -7 then your mix that you have done at K-14 will now fall 7 dB short the whole time from 0 dB VU and then you can start mastering the signal and getting back up to read 0 on the VU meter again meaning the music is now averaging - 7dB rms instead of your mixing reference.

Don't forget too that K system metering is also about consistent monitoring volume in your studio which you can set at around 83 to 85 dB SPL C weighting.

"If your master is @ -6dB, yes, you have 6dB of headroom according to the real scale (the VU meter value)."


So are you saying that the track/bus meters in cakewalk are a type of VU meter?


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"When you use the K-14 scale, the 0db reference point is moved down to -14db, so hitting +6 actually means you're hitting -8db on the "real" scale. "


So basically the "real" scale is the meter that cakewalk provided?


K-20 is -20db to -14db or in "real" scale -6db to 0db
K-14 is -14db to -8db or in "real" scale -6db to 0db
K-12 is -12db to -6db or in "real" scale -6db to 0db

So really the headroom for K-20 is 20db to -14db, K-14 is -14db to -8db, and K-12 is -12db to -6db? 
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Does RMS mean the average signal level of the project/song?

Does RMS mean the average signal level of the project/song?

It can. An average RMS reading can be for a whole song, a portion of a song, or any other arbitrary interval of time. When you're watching an RMS meter, it's typically showing the average over 50 millisecond intervals.

Headroom refers to how much the signal can jump up before hitting the absolute limit (0db in a digital system). 

So if your song has an average value of, say, -20db that means there's room for 20db-high peaks if you want them. You normally don't need that much headroom for pop music, but you certainly do in classical music. In rock music, most of those peaks represent drum hits. If you want a snare to really crack, being able to make it 12 or 14 db above the rest of the music is going to sound much more dramatic than if you only have 4 db to play with.

So basically the "real" scale is the meter that cakewalk provided? 


I think I understand what headroom is now. The more headroom, the more dynamic range to play with before it clips. Thanks!

I think sharpdio23 you are on the right track. No, Sonar track and buss meters (and most DAW's) are not really suitable for showing K system levels. Because a Sonar meter will be hovering around (-17 for a K -14 ref level. Sonar's meters show true rms which is 3 dB down form the peak value) 
A meter is not much use hovering way down low while you are trying to read rms K levels. You need a meter that is showing FSD or 0dB VU while the digital ref level is right down at the ref level. That way you are seeing the full range of the meter.

You can buy them and install them easily though. Studio One meters can be put into K system mode at any time which is rather cool. (busses and Masterbuss only)

VU meters also show something else and that is the ballistics of the music or ie how the needles move! You wont see that in any other meter. There is a lot of information in how a VU meter moves on a very well balanced mix and mastered track. When your mix and mastering is not happening you will see it in the VU meter. It makes you go and hunt down the tracks that are making them move wildly but not offering any real extra sound. eg silly subsonic material that is of no real value. 

Thanks Jeff.

Maybe my question really should be, what kind of meter is the one provided in cakewalk tracks and buses?

The metering provided in Sonar is rms and peak which is great. (depending on what settings you have for the meters of course) It is just the rms values are all showing low down on the meter scale that is all. With a proper K meter the rms values are all up high around 0 dB VU.

The ideal thing is to use both an rms K system meter and a normal peak meter. You definitely need peak metering too because the VU won't show damaging peaks at all or very well so as we are in the digital world now peak metering is a must. But for some reason a lot of modern DAW's have abandoned rms or VU metering in favour for peak metering. 

Back in the analog days we only had VU or rms metering and we did not worry about the peaks because the built in headroom of all the stages in an analog recording chain basically took care of the peaks by themselves and without fuss usually without any audible effects. 

I'm understanding quite a bit, but still have questions.

What I know so far is that it is a good idea to have an rms meter and a peak meter since an RMS meter only shows the average perceived cumulate volume and the peak shows in real time where the audio peaks. Correct me if I'm wrong.

"It is just the rms values are all showing low down on the meter scale that is all. With a proper K meter the rms values are all up high around 0 dB VU. "


1.What do you mean when you say "low down" and "up high"?


2.As for a peak meter, would you suggest a plugin that is a true peak meter?



3. Do VU meters usually read slightly lower than the true RMS value?

In answer to your questions.

1 I am referring to where the meter is indicating. eg the rms value that is actually showing on the meter. If you are using a K reference of say K-20 and Sonar is showing that at -23 dB rms then the meter is indicating something that is very low down on the meter scale itself ie it is hard to see because it is almost at the bottom end of the scale. But with a K meter you are looking at something that is right up high on the meter scale right up near 0 dB VU so it is much easier to see!

2 No, I think most DAW's cover peak metering pretty well and I don't feel you have to go and buy a better peak meter although you could and you might be able to see more information as a result eg the BlueCat meter.

3 Yes, with a sine wave the VU will show the same value but with music or pink noise the VU meter will read slightly low but slight being -1dB down from 0dB which is not a big deal. I tend to push the music right up to 0dB VU which means the overall level might end up a little louder in the end but that is usually OK as it means a little less you have to go in the mastering stage.