Why the fascination with subwoofers?

+1 @millercarbon The wide unknown is a fun place. Someone was asking about a cheap good crossover, check out Mini DSP. With a digital crossover you get exact slopes and have the option of doing room correction with Room EQ Wizard and can have even more fun with Multi Sub Optimizer. I prefer a Mini DSP with IIR over FIR filters as the IIR filters operate at 24/96.

I’ve heard my Magnepan 20.1 speakers full range with no subwoofers and they sound great. I added two properly integrated stereo subs and listened a year like that and it was even better. I added two more subs and measured/corrected the room and the “WoW” happened. Nothing is boomy, just accurate full range bliss. I don’t have to turn up the system nearly as loud to hear full range. In the end I’ve spent almost as much in subs as my mains which by all accounts are SOTA. That’s how important I feel the lower octaves are in music.

Jump on 2 subs asap dude!!

LISTEN to @hifidreams.  He knows what he hears, and it is all good.

This is a very timely topic for me as I am about to buy some new speakers. I have listened to both the Vandersteen Treo CT and the Quatro Wood CT at Audio Connection in Verona NJ. I was very impressed with both. These demos however were performed using John Rutan's house Aesthetix amps.
My amp is a Pass X-250.8. It is powerful and has very good bass control. I would love to bring it in and demo the speakers with my electronics but the problem is that it's so heavy to put in the car along with my pre and drive for 1 1/2 hrs to Audio Connection to do a more proper comparison between the two speakers. Also, my wife and I will be moving in a couple years when she retires so my listening rooms will change over time.
My two questions are:
1) Is it better to get the Treo CT and add a Vandersteen sub that can be positioned in appropriate locations as we move or just get the Quatro CT and not bother with subs?
2) What's the consensus on adding an AR REF 6 pre in the future to compliment my Pass amp, or could anyone recommended a different similarly priced preamp?
Thanks so much for any advice.
Bruce

Few "full range" speaker go much lower that 40hz. That is a whole octave missing. And a subwoofer designed for home theatre is not what most audiophiles want.  They want one that plays music convincingly.  In fact home theatre speakers are not what audiophiles seek either.  Now there are true full range speakers, but they are typically very expensive and quite large.   Often a good subwoofer paired with high quality monitors will be a good option, even preferred by some.