Audio EQ - Should all the EQ numbers basically net zero?
Like, if you take away 4db "from treble", should that be distributed roughly amongst bass and mid or solely either if you want it to be heavy for that range?
Is it like an equation that benefits from balancing it out?
No. The eq should be the inverse of the room/speaker response; it’s irrelevant if the gains add to zero.
And, most music has way more energy in certain (generally lower) bands, so it’s not like making the numbers sum to zero results in the same total energy.
I think that's a very important point. If you "balance" the EQ like you describe but you boost a frequency band that our ears are more sensitive to and lower a band that we're less sensitive to by the same amount of dB... The mix might still sound louder than before.
So don't worry too much about the numbers and heed the great advice given in this thread.