1) He listens to Jazz and Folk;
2) He may or may not have speakers since he hasn’t bothered to tell us what he has.
3) He likes bass, only cares about the bass, has told us nothing about what he prefers for other characteristics of a speaker.
4) He has a room, it is small, but who knows where his speakers are placed, where he sits, or if there are setup problems.
5) Any speakers with horns are out because as he puts it: " I have a small size room and no I do not want horns!! I am not a huge rock or pop genre listener... all I need is “ENOUGH BASS”".
6) He wants to spend less than $4000.
So given all the amazing information provided, I suggest the following:
1) Cerwin Vega SL-15- "large motor 15" woofer for punchy bass".
2) Polk S60 with "(3) 6.5” low distortion mica-reinforced polypropylene cones with four-layer voice coils for clean, clear bass, better linearity, and dynamic mid-range" and " Exclusive Polk Power Port technology for greater, more impactful bass".
3) Bic Venturi DV-84 with "Two 8" polymer active woofers, two 8" passive radiators".
4) Dayton Audio T652 with " Dual 6-1/2" woofers provide superb bass power and punch" . . . "for unobtrusive yet modern aesthetics and incredibly deep bass."
All of the above meet your stated criteria and should provide, as you put it “ENOUGH BASS”.
" happy listening....
Cheers"