Demise of bass quality in Main speakers

Lots of really Great answers throughout.

My overall impression from comments above is that subwoofers are being marketed and used inappropriately in many situations to solve bass driver Quality issues.  Subwoofers are not intended for this purpose. They are supposed to deal with sound ranging below 80 hz, which generally is not as detailed as sound waves above this.

It's not rocket science.

OP I think I agree with some of your points, but also feel lost on what you're trying to get to reading your first and last post. Marketing wise someone could probably write a 100 page dissertation,  but I think bass performance boils down to cabinet size and competing at a price point. I've tried to give away great speakers and they've been vetoed because of being too big - even lil floorstanders with dual 8's. 

I agree it's not rocket science. I have some great speakers that can do bass solid for most music. Frankly I'm blown away by them for price and performance and that's why they're keepers. For true 20 Hz and below performance I needed to add a sub. It's pretty tough to compete with a good sub for that last bit of low extension with the dedicated high power amplification and cabinet size. I prefer to cross at about 30 Hz with my mains having solid performance down to there though I understand the 80 Hz method.

I have had some pretty big speakers that had stupendous bass, but I couldn't control it in my room. This is the other advantage of subwoofers though you could also use DSP etc to tame powerful speakers.  As someone else stated multiple subwoofers can be used for room issues to get ideal bass response throughout. I will be going to 2 subs when I can fit them, but have heard of many going to 4 for most even response. 

I love 2 channel, but a lot of the "full range" speakers I would love to have at my price range and far beyond that don't dig down to 20 Hz or below. I listed some very expensive speakers that do go below 20 Hz on another site and was chastised as being a snob for providing them as good examples. I think it's all about building the best system you can afford in your space for your tastes,  but it sometimes seems to get way overcomplicated. 

I’m of the opinion that sub(s) should not be audible themselves in the room rather they mesh with the mains to create a single sound. The reason I added a REL to my system was a search for increased fullness in the music. The primary benefit I actually received, and was not expecting, was how great my system now sounds at low / lower listening levels. My ears thank me everyday.

@dmbwire 

Maybe bass from your main speakers was enhanced by the subs.  I contend main speakers often struggle with bass Quality due to smaller drivers and cabinets. Subwoofers are now being used to correct all this.

Your initial comment about fullness at lower end are what subwoofers are all about and the new subwoofers tend to lack fullness because they also have smaller driver sizes.

I find that a pair of 25 Hz quarter wave folded corner horns driven by good quality 15 inch woofers serve my modest needs for bass.  These handsome teak veneered Bill Fitzmaurice designed subs have an output at 25 Hz that is identical to the 1 kHz reference tone in my DEQX DSP equalized and controlled system.  The only possible downside is that they are 18 cubic feet each.  Horn bass is the best bass.