Monitor Calibration with K-System

Bob Katz Leave a Comment

Name: Richard Furch

Message: Bob, I have a quick question after aligning my monitors for the K system you outline in your (outstanding) book. I’m a mixer though. I don’t want to waste your time, so here goes: 

1. I run ProTools with Apogee converters aligned at -20dBfs=0VU (I’m looking for more headroom than normal). I inserted a signal generator plug in at 0 on the fader and Pan to one output at -20dBfs.

Don’t trust the signal generator plugin. Unless it is guaranteed RMS-calibrated, it will probably be less than accurate. Download the -20 dBFS RMS pink noise from our website. It’s a stereo file. Play one speaker at a time and don’t play with pan pots, play it in stereo but mute one speaker at a time and tell me how different that is than your own generated pink noise.

I aligned the monitors with Pink noise/C weighted/slow/one channel at a time at 83 dB SPL and marked theposition. (a C24 with db readout).

2. I checked that 6 dB down from that actually meant 77dB SPL and it did. 

3. So far so good (I think).

Assuming it was accurate pink noise then you’re right “so far so good”. Except if your monitors are very close then they can end up 3 dB OR MORE louder than mine regardless of the accuracy of your calibrations.

4. Using K14 (6dB down)

Meaning that you set your monitor gain as in the paragraph “I aligned…” and then left it at that monitor gain (6 dB down from the 83 setting) and mixed to that, right?

I mixed a contemporary rock/pop singer songwriter track by ear only (without checking the meter too often).

A good goal!

5. Mix finished, I’m at -8 to -10 VU, even though I would say that sounded pretty loud while mixing (probably a 2 or 3 dB louder than I would normally mix).

What was the peak level of this mix?  How far did its highest true peak get on the peak meter? You’re saying that its VU level (on which VU meter?) is what?

Now in the end, regardless of the miscalibrations or assumptions, your method of monitor calibration and working to that monitor gain while largely ignoring the meters will probably produce a good, clean mix that sounds great and is VERY ready for mastering. It may not be ready to send to a client who expects something hotter, but it is ready for the next stage and you can never say you ruined the mix  :-).

Now for possible explanations and tools to trying to get you closer to your stated goal of producing a true K-14 mix:

First of all, try to get the LM5D meter from TC for your Pro Tools Rig. If not, the UAD limiter has K-metering, for example. Could be a combination of the inaccurate pink noise and the position of your loudspeakers. When you said “I’m at -8 to -10 VU” what meters are you using to measure that? Are those accurate VU meters that were calibrated for -20 dBFS = 0 VU?

6. Confused, I played the same mix releveled to 0VU

I’m curious, using what meters?

(obviously I still have miles of headroom in the DAW). At 0VU I could positively not take the volume in my studio for more than a minute (and I have a hiphop/rnb background as an engineer check my site 

7. What gives? At the 83dB alignment I can positively not get to a 0VU mix without killing myself.

You betcha!

Trying to put things in perspective, keep in mind that your 45 inch speaker distance completely changes the landscape, raises the subjective loudness above the typical points by as much as 3 dB compared to, say a 9 foot speaker distance. That, combined with a possibly mis-calibrated pink noise signal and we’re probably on different planets.

First, compare your pink noise signal and method with mine, just to see how far off we are.

Then, assuming your pink noise signal was accurate, I’d say a true K-14 mix (forte passages at K-14 Zero) with your speakers at the 45 inch position will need to be reproduced at around -9 or -10 dB! Compared with my -7 to -9 dB for the same musical source. Keep in mind the “-6 position” for K-14 was based on the theory of a mono speaker and mono pink noise, but two stereo speakers raise the loudness 2-3 dB so a true, conservative K-14 at about 9 feet speaker distance will probably reproduce around -8 or -9 dB on the monitor gain, so -8 or -9 dB monitor gain is the recommended gain for a K-14 with 9 foot speaker distance.

And then your speakers are yet 2 to 3 dB louder than that by virtue of their physical position. So a true K-14 (conservatively measured) will probably reproduce on your setup at -11 or -12 dB, which is 5 to 6 dB lower than the gain you were running!!!

Does this help?

You have done well and you’re using the right language and speaking clearly, just fine so it’s just a matter of sorting it all out. I must say that using a hand calibrated monitor gain is iffy in itself, you cannot easily move it off that -6 position and readjust it to, say -9 without jumping through hoops. Ideally your monitor controller should have 1 dB steps so you can help debug this. With the monitor set at a fixed -6 dB position I’m trying to get a handle on what you meant by “-8 to -10 VU”, whether that was on peaks or average, loudest passage, etc. etc. etc.  It gets complicated to debug. We’ll sort it out, be patient.


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