Shortcut or badcut?

It can be done, But..

Generally to accomplish doing so and getting it to perform and sound worthwhile will require 'pro sound' equipment of the sort you see at concerts. They have a whole range of devices and means to make those arrays 'do what they do'...*S*

@mijostyn has your best option, but level and balance control over the back pair (at minimum...eq added to that is a plus) would perhaps fill the bill for just sheer volume.

No guarantee as to what you may hear, however...*shrug* 

I am quite happy with the sound I have, so I will take the given advice and not mess it up with a dumb idea.  The SuperTweeter seems like the way to go, so I will $tart $aving.

Thanks for the info.  Much ....appreciated.

You will lose your sense of sound stage.

OP... What is your definition of "air?" Is it to increase the high frequencies, meaning more high-end extension? Or are you looking for the phenomenon of air around the instruments? This would increase the space surrounding each instrument and improve focus.

If all you want is more high-end detail and extension, then super tweeters are worth trying. For true "air" in the audiophile sense, then it's more complicated.

Sincere thanks for the info and suggestions.
I just wanted more high-end extension. Sometimes I miss the shimmer and sparkle of the higher end.  I'm also one of those weirdos who think the inaudible higher frequencies have an effect on our bodies, and therefore, our listening experience, just like the very lows do. (I was once exposed to 22kHz, through an apparently loud driver, and although I didn't hear a thing, I felt like being exposed to positive ions, like at the seashore. )