People complain about lack of bass, not enough mid range. Solution?

Ok, I get it now. No room acoustic treatments needed and bi-amping is the key. I'm doing it all wrong.

Try optimising speaker placement. Then, try some room treatment (diffusers, absorbers, etc) - As other have noted above, you might find the bass magically appears!

Following the above you may wish to bi-amp -- or not, as it were.

OTOH, if you liek the idea of two bi-amping don't deprive yourself; but you'll still benefit doing the above

Geting the bass "right" should improve midrange detail and linearity, not detract from it.

As a starting point rule of thumb, you want the distance between the tweeters to be about 83% of the distance from your ear to either tweeter.  (Unless you have one of those rare speakers designed to be in a corner or against the wall.)

Most speakers need to be at least 2 feet from the wall, up to about 5 feet, unless you've got a huge room.  So maintaining the 83% ratio, experiment with moving the speakers in that 2-5 feet from the wall range.

Unless something is damaged or mis-wired in your speakers, speaker placement is 90% of the ball game in getting frequency response right.

I just spent a few days playing with different component positions of power cables - (Shunyata Delta NR v2's and Level 3 Anticables) plus fiddling with the controls on REL S812 subwoofers - all this after doing some room treatment. Quite amazing what can be done by judicious experimenting and shuffling about with these variables.