Is bass the most important frequency band?

@dabel

My monitors have been with me 20 years and they’re keepers. But they do not dig deep enough.

Well there is no way to tell if my speakers go down lower than yours, or if I’m just satisfied with less. But does show how silly it is for folks to argue about equipment given we all want different things.

90% of the brains processing power is between 500Hz-15kHz. The region that processes sub-500Hz looks more like an afterthought, barely any brain tissue dedicated to it.
So, the 500Hz-15kHz would be universally the most important frequency range, and is key for natural sound, because that's where our brain is the busiest.
There's so few audiophiles who aim for natural sound - most go for controlled / processed sound, so nobody really cares about this region where 90% of the brain tissue is concentration on.
What each of us perceives as key aspect is highly personal.Bass certainly has a special role, as its perception is also through the body (internal organs resonating) and not just the ears. Makes for a big added layer of experience, for good or worse.

 What a balance we must achieve to please ourselves. And on top of that, mood matters, damned age matters now, then there is the environment for listening. Assuming that all goes well I can't top the experience. But  it is just about anywhere in the audio spectrum (except treble, which I just don't hear well anymore), it has to be right for me. Midrange can make me cover my ears, 'bad' bass loses my interest, and even noise if it is too high makes me walk away. If it don't sing, I'm walkin'.

I don't care much for bass compared to the midrange frequencies. 
I'm one of the few .7 magnepan users who don't feel the need for a sub. 

I think many have this right. Because the room is in essence a bass instrument the variables involved make accurate bass difficult to achieve.
cd318 is also very right. "most systems don't even try." This is for good reason. IMHO no bass is better than bad bass. 

I have no problem enjoying music with no bass but you can not reproduce the "Live" experience without it. One can argue about the best way to achieve accurate bass but many residential spaces preclude making accurate bass and at best you might be able to get it at one location in the room regardless of what equipment you use and how you set it up. Using multiple subwoofers definitely helps but you still have the entire room and it's contents vibrating at various low frequencies screwing things up. Room control helps but it can not overcome poor room acoustics and items resonating and buzzing. For fun get a test record or CD and play a 40 Hz sine wave. Turn up the volume and listen to what happens. The lower you go the more items will join the symphony of buzzing and rattling. Items ringing add a higher frequency halo to it. This is usually masked by the music so you only hear the loudest problems under the right circumstances. It took several months to stop my theater screen from acting like a tambourine. Tip of the day, get a roll of butyl glazing tape from your local glass company. You can stop any rattle with it! 

Even the most intelligently designed rooms will have some problems. If you want to know what your situation is like take snapshots of the room at various locations with a measurement microphone. You can get a mic and a complete computer program for $300. It is the best tweak you could ever buy! Ideally you should get the same frequency response at the various locations. What you will get is wildly different curves. 10 dB swings are the rule and 20 dB swings are not unusual. This will happen even with a swarm system but to a lesser degree.

Unfortunately, there is no acoustic treatment that can overcome a bad room and the best solution is to limit low bass so that exaggerated low frequencies do not overcome the midrange. IMHO there is no one most important part of the audio spectrum. Midrange sibilance is every bit if not more aggravating than bad bass. I personally can't stand a system that is too bright. Old age will fix that problem. But, I have to say that hearing a system with great bass is great experience. You get that same rush you get at a live concert when the band lights up.