1) human capability to perceive distortion varies with frequency
2) how many "octaves" of music are handled by each driver
3) where most of the musical energy exists in a recording of normal music
4) where the crossover frequency is set
1) Simply put - the lower you go in frequency, the less sensitive the ears are to distortions in the signal. Pretty much, as soon as you come out of the midbass octaves, perception is pretty clear - so IMO not as much of a "mid vs. tweet" issue - but technically, perception is still increasing as you cross that crossover frequency into the tweeter range.
2) This of course varies depending on where your crossover frequency is set to - but usually, that's somewhere in the 3Khz-5kHz range - meaning your tweeter is handling about 2-3 octaves worth, where the midrange is handling somewhere between 5-6 octaves worth (or more, if there's no sub!).
However:
3) There's WAY more musical material in just about any recording in the range around 100hz through 2000hz or so... and lots of the musical material that exists outside that range (ie. tweeter and sub) are harmonics and ambient elements that more or less give the music energy and define ambiance and reality, as opposed to the "core" content - which is why so many clock radios and computer speakers that can't play outside that range still play the song - but don't sound "great" by any means.
So - one question becomes whether your priority is "loud", vs "detail" (like all this ambiance, imaging, detail, and reality
).4) The crossover point usually more or less is just a matter of how much material the tweeter handles vs the mid, how many octaves each get to split... but it's really at a critical point, and it can really affect the install.
For example - one "extreme case" - in my pathfinder, I'm currently running NO tweeters. Why? I have six midrange units that can play all the way up to 18kHz (Aura 3" neos). In this case, the priority of "which driver is more important" falls completely on my mids - so I need to angle and arrange them properly, since they are fully defining the soundstage and imaging.
However, in another extreme case, you might find someone with a 3-way component set, with a midbass driver playing all the way up to maybe 300hz, and a midrange only playing up to about 1200hz - only two octaves. And then, a tweeter playing from there up - four octaves.
This may be done intentionally (with a tweeter that can DO it!), putting more of the musical content on the tweeter, because the tweeter is smaller, easier to mount, easier to angle, not requiring a baffle or enclosure, etc - and in that case, would define more of the soundstage, particularly with regard to imaging and ambiance.
So it's not a debate that's got a "winning side" - that's my point.
It's a debate that changes back and forth, as you change all these parameters and priorities.
And a great reason for a thread!
