Is bass the most important frequency band?

Ballpark $100 per Pod. They are priced higher https://www.audiogon.com/products/townshend-audio-seismic-isolation-pods but call and order direct from John Hannant he will give you better pricing. They like to recommend four per component, but I use 3 under most things and have played around and don't really notice any difference 3 vs 4. 

My first big surprise with Pods was how much resonance was coloring everything. The more Pods the more that goes away and the more every instrument sounds as it should. The cumulative effect is really something. I was listening to Brubeck last night. The whole record is a gimmick- Time Out, they are all different time signatures- and it usually gets tiresome and so hasn't been played in a while but last night I was struck over and over again how much more interesting it is when it sounds like a real piano, sax, and drum kit. 

The other thing, my room has hardly any treatment, it keeps getting put off and now I am so glad! Podiums and Pods removed a huge amount of "room" resonance that I would have sworn could only be handled with bass traps and diffuser panels! 

That is why when we did them recently at Brandon's he said it was worth a couple thousand in room treatment alone. That was Podiums, they have the biggest effect but also the biggest price tag. 

Hopefully that is enough info so you will be able to figure it out but if not you can always ask for more. 

Really good bass always was pretty much impossible to achieve. People came up with all sorts of solutions. Do a search, with enormous horns and speakers built into walls there are people pretty much turned their whole house into a subwoofer. I heard a bunch of systems with really powerful impressive and deep bass. But never anywhere heard really good bass until I built my DBA.  

The difference is hard to describe in a way people who have never heard it will understand. It is not so much that the bass goes really deep, although it does. It is not so much that the response is ruler flat, although if that is your thing it can be, and a whole lot easier than any other method. It is not even so much that the bass is clean and tuneful and articulate, although it is all of those and in spades.  

Mostly what it is, the DBA gives a sense of envelopment, of being in the recording venue and space. This helps make not only your speakers but your entire room disappear. This is something that is heard, better yet felt or experienced, even when there is no apparent bass to speak of being played. When I put my subs on Townshend Pods for example the improvement was immediately evident in these terms long before any real bass was even being played. 

I have heard plenty of mightily impressive bass. I have heard some exquisitely tuned systems that I am sure measure within a gnats hair of perfection. And yet I have never heard anything with that you are there sense of envelopment that is so easily achieved with a DBA.  

Not surprised. If you're ever in the Seattle area come check it out.

This question is much more complex than it is being given credit for.

Two examples, from the extreme opposite ends of the spectrum. At the extreme low end, really good bottom end reproduction improves the sense of envelopment and improves the sound well up into the midrange. This is the case even when there is no discernible low bass present. I heard this when first going from one sub to 4, and again when putting all my subs on Townshend Pods. In particular with the Pods I distinctly remember being surprised because I was expecting and listening for low bass but what hit me instead was the greatly improved imaging and envelopment. What was surprising was the low bass I had put the record on for hadn't even started yet. 

Something similar also happens at the extreme high end. There the addition of Townshend Super Tweeters would seem to only affect from about 15kHz and higher. But yet in this case clear improvement is heard well down into the midrange, and even some pretty low bass sure seems to sound more tight and articulate with greater clarity. 

For these reasons I think it is overly simplifying to talk about frequency bands as if they can be viewed in isolation. They can, of course. But only by discounting a lot of really significant phenomena such as these.

Use the above methods to get the bass right and you will be surprised at the improvement in those "details". 

Oh wait, sorry, other bass discussion. Use the below methods. 

room modes, which are what we hear as lumpy boomy etc bass. But the solution to room modes is multiple subs. Once you understand this and change from the old-school two locations mentality to a DBA suddenly a huge amount of "room problems" goes away. 

The next biggest source of "room problems" is the room being made to vibrate by speakers physically coupled to it. This creates resonances and ringing that ruins a lot more than just the bass. When floors, walls and ceilings are all being made to vibrate by physically coupled speakers it smears and colors all up and down the audio band. 

The solution to this "room problem" is to decouple the speakers by putting them on springs. This is impressively effective, as has been demonstrated many times. 

If the goal is improved bass response then both of these should be done first, long before any of the other suggestions. DBA and isolation are whole orders of magnitude better than anything else you can do. The improvement you will hear from doing these goes does indeed greatly improve bass response, but also goes far beyond that one thing.

DBA, Townshend Podiums and Pods, huge improvement in detail resolution and bass control. 

This by the way will also reveal why it is not so much "a" frequency band, but whatever band has the worst most colored resonance. DBA and isolation greatly reduces these revealing a huge amount of hidden character. 

The most important frequency band is the one you let your mind obsess over.