Thanks for this info. I'll check it out as soon as I can!

My reason for posting about testing for freq response is:
Any frequency that is loudest will be the reference when testing with pink noise.
 
 

A good test signal for setting up correct monitor levels is band limited pink noise.  You remove everything sharply below 500 Hz and above 2 KHz with some steep filters.  As a result there will be a level change and it needs gain to be added to compensate.  The quality of this test signal avoids all problems in the low end of your room.  It is not feeding anything into the room where the room may be unstable or inaccurate.
 
eg if you are using a K-14 ref level a sinewave with its peaks reaching -14 dB FS will produce 0 dB VU on the VU meter.  Full range pink noise at K-14 reaches about -1 dB on the VU meter which is to be expected due to the randomness of the signal.  If you create the band limited pink noise filter, the signal needs close to 8 dB of extra gain to make up the level.  This depends on the steepness of the slopes around 500 Hz and also 2 kHz.  Switch the filter in and out and note the VU meter changes.  And also the SPL changes in the room.  There should be little difference.  I adjust each monitor for 83 dB SPL individually and that leaves me with a nice 85 dB SPL when both are on.  You should check the volume settings on the rear of your active monitors as well for fine tuning level there.  They are not always exactly the same even if set in the same position. 
 
Full range pink noise at the ref level and at 85 dB SPL is quite loud compared to music at that same level.  Music sounds quieter to me at that same  SPL level.  Your ears are hearing at 85 dB SPL and are in a good place to balance EQ and levels well.  I find having a permanent SPL meter in front of me keeps me honest and in control.  If you are listening at quite precise levels while you mix I feel it helps you mix better too.
 

 
From Bob Katz's site :
 
Pink noise, stereo :
Pink_min_20_dBFS_RMS_uncor_st_441.WAV
 
Band limited :
Pink_Noise 500-2K -20 dBFS RMS Lt.WAV
Pink Noise 500-2K -20 dBFS RMS Rt.WAV
 

Just to let people know the band limited pink noise (500-2K) that has been posted on Bob Katz's website above by Paul  is already perfectly gain adjusted so there is nothing to do with those signals. They have been corrected to read the K-20 level.
 
When comparing to a sinewave BTW at exactly the same level you will notice both pink noise test levels are about -1dB down on the VU meter. This is quite normal.  Probably due to the random nature of the pink noise signal.  I tend to use the sinewave test tones for exact level line up and any voltage measurements eg from your interface. The noise is great for monitor calibration and setting SPL levels etc in your control room.  Avoid using sinewave test signals for these types of applications.  With sinewaves you only have to move the SPL meter a small distance for wildly varying levels etc..Pink noise is much more consistent across the spectrum.  Band limited pink noise is even better as it excludes the bottom end of your room.
 
It is handy to add 6dB and 8 dB of gain to the pink noise signals for the purposes of making a K-14 and K-12 versions of those test signals.
 

Thanks for those tips Jeff!
 
I could be mistaken, but I think C weighted is a form of band limitation that agrees best with how we hear. And Jeff mentioned rolling off pink noise at (500-2k) I'm guessing this is best for most home studio rooms....in either case you're modifying the pink noise to offset some other calculated condition either in your hearing or for the space.. K-20 seems unrealistic to me if you're trying to get in the middle on terms of SPL. Not fighting the loudness war but not making the listener turn up the volume on your mix either.
 
Do you use K-20 on all of your material Jeff? Maybe I'm doing something wrong.
 
Funny we're discussing the K system and another poster post the same thing right over this thread.

The C weighting listens to more (bass) of the spectrum hence it takes in the low end of the music much more.  With the band limited pink noise however the C weighting is not so important but I would still use it on that setting none the less.  As you say Tim it is just leaving out the bottom end to not involve the low end of your room.  The gain however of the band limited pink noise is adjusted to compensate.
 
Tim I work at K-14 a lot and K-20 at times. (for very high quality projects) It makes no difference. The only difference is at K-20 everything is just 6 dB lower down right throughout your project that is all, hence more headroom.  The VU meters need to be recalibrated for K-20 though, hence they still show the same readings eg everything around 0 dB VU.
 
And of course the SPL level in the room also drops by 6 dB so you have to turn up your monitoring level by 6 dB so you back to 85 dB SPL etc..
 
The only thing is you end up with a mix that is sitting around -20 dB FS instaed of -14 dB FS.  But you have got 20 dB of headroom for transients and things hence it will sound a tad nicer.  But in mastering though you have got further up to go to get the track loud.  eg if you want to end up with a loud punchy master around say -10 db FS then from K-14 you only have to add 4 dB of rms gain. But at K-20 you have to add 10 dB of rms gain. So there is just a little more work to do that is all.
 
Another reason why I like K-14 a lot too is my Yamaha digital mixer is calibrated for K-14 too. ie I get +4 dBu at the output exactly when the I am at K -14.  Meaning the output of my digital mixer can produce a whopping +18 dBu at 0 dBFS. Something that many average audio interface cannot even approach. There is a big hefty power supply inside the digital mixer which has no problems producing very high output levels with no distortion or clipping in sight.

Thanks Jeff for that information! I was under the impression you mainly used K20. I'm glad to see you using K 14 a lot as well. I think it lines up the most closely with the genres I work with so far.

I try mixing at a -4.5 db level on the master track.
That way i can provide enough head room to boost up when needed.
Usually with the Boost11 plugin.