loudness: peak & rms

i've been getting better at mixing and during this process i've been listening to a lot of reference mixes

what i've noticed is that for example while SONG A & SONG B are both maxed at 0db as they should be, SONG A is waaay louder.

I found a thread about this on gearslutz but i wasn't really understanding.

something about rms and peak and how we perceive audio as humans...idk

if anyone is willing to offer information on this subject, possibly a lamens terms if there is such a thing,
thanks in advance.

-Copper Tony

EDIT: when i mix i do everything in the computer. i dont have an external mixer or anything. only reason i add this is because i read on tweakheadz and many other places that u have to calibrate the mixer using a test tone of 0dbVU. i dont know if this is only for external mixers, but i would assume so.

One of the songs is denser and more compressed and likely distorted (not necessarily clipped), in addition to possibly being made to psycho-acoustically sound louder by other means (distortion, aural exciters, etc), basically...making it seem louder, despite peaking at the same level. Our ears perceive volume most from averages not instantaneous transient sounds. If you squash the distance between peak and average levels, you will have constant density or constant high levels...at the expense of the aesthetics and inherent dynamics of the music.


:: An example of a fairly loud Post-Rock song by someone who I often collaborate with.

This post was longer, but I got rid of nearly 3/4 of it...as you said laymen's terms. Honestly, if you really want to know about the subject, you probably should read what was said about peak vs. average RMS levels, at the resources you mentioned. To oversimplify, one measures the instantaneous levels, the other is a mathematical quantity of so-called energy/power over an elapse of time (average level). In the current context, this is not a mixing topic, this is a pre-mastering topic.

I can post what I initially posted, which did address those things, but I likely won't be around much to reply. I'm sure others will help though, just as well.

thanks, this really helped me out.
i guess it is more of a mastering type question

im gonna experiment with exciters.

A lot of compressors have peak and RMS. Normalisation also works off peak and RMS. Peak transients are used to mark the highest most value whereas RMS (root mean square) measures the average peak values across the timeline of the sample/audio. RMS will always sound far louder and denser as the average peaks are calculated the process is applied to this average.

yea ive found that the rms for my songs is around -15/-10 which seems normal

peaks at zero ish obviously

thanks for the advice everyone