I wanted to share this simply because this is what we do. We extrapolate information to another realum. Basically, mastering is taking the pro format and turning it into the consumer format. It gets much deeper than that too! Say, you get a 2-bus that has different 2-bus dynamics from left to right channel. Example, the "rms" figure for the left is 16.2 and the peak is 0.6. The right is 18.7 (rms) and the peak is 0.0. This is when you extrapolate the values using science digitally and your ears to perform the unheard of....getting proper imagining when the mix is out of calibration. Center will lean way off on this. We fix that as well with Mono frequency eqtrapolation and even multitracking the 2-bus if need...as many as 16 tracks out. Remeber, we mastering engineers also take things back to analog and restore upper lost harmonics from the original masters using analog eq and such. One helpful hint: The equilizer is your best dynamic restoration friend whether it be compression or expansion of dynamics, single band or multiband. Extrapolation exist if you do not have an undo. You are now playing chess and looking 10 to 20 moves ahead..all of them if outside the digital domain will cause certain problems for sure (more extrapolation). Minimizing this is the key..damn good mixes. Believe me, well established pros send bad calibration to the point of asking for a remix..or asking If I can remix. These days in indie, I want vox and instu. separate "two 2-buses" so I can make the warts diminish rapidly. Food for thought..back to the realum... I stress to studios worldwide, "calibrate your equipment scientifically with tones and the arts will be better off for it" Make sure that your wires to your outboard gear is in calibration. One dusty pot on one piece of equipment without metering in stereo can cause the major headaches us mastering engineers must contend with. Another example of extrapolation is speakers. On another forum here Cedar is stating something I know to be true and others are saying NO and not getting it. (reference is NS10 Sound) Believe me please, if NS10's sound nasty to you..something in your calibration and mix is ^#$%ed up! They are pro speakers not mastering speakers. Make them sound sweet in mixdown (pro stage) and then us mastering enfgineers have something viable to work with..and watch the cones on bottom. Rule of thumb is 1/2 (half) the cone motion for bass lines sustain, full for the kick. Simple! Make them sound like the best speakers (60hZ and up) you have ever heard!... then your mix is masterable because not only we know what we are getting but at least their is room for the conversion from pro to consumer..Cedar says it travels..he is right! it travels to the mastering engineer and many, many, many speakers. Listen to what the Man says! If anything sounds nasty on the NS10's , re-evaluate your mix and eq. SImple. Just do it. Work at it. Now, calibration. How many of you that mix actually put test tones through your metering system, use a VOM and measure voltages, use a impedance meter (toa makes a great one only $400) and check phase of your wires? Every studio should have an O scope and know how to use it! So we are talking about home based studios? Absolutley! For what an O scope and 9 hrs of research ( to learn it) cost, it is only equivalent to 10 days eating out at night. This is not a rant..but teaching. Teaching important skills that should be employed. It is only a snippet..but all of it is viable. Mostly, make your music vibe. IF you do not get chillbumps on your body from your work, seek help and make it so.