Please suggest bookshelf with best bass response under $4000 pr.


Lately, I've been craving deeper, tighter bass. I'd like to hear some ideas for replacing my Silverline 17.5 monitors. Is this a stupid question, due to inherent limitations of driver size imposed by typical bookshelf dimensions, or might I actually do better with another speaker? Amplification is Wells Audio 150 watt SS Majestic integrated. Source is aging Jolida JD100 tubed cdp (in new year, I plan to replace this with another SS cdp or a transport/standalone dac combo). Thanks ! 
stuartk
I just found an a'gon ad for monitors with this claim: 

"The __________ are full range Studio Monitors that will
provide the entire frequency range, therefore, eliminating the need of using a subwoofer which cannot be fully integrate with speakers".

I wasn't aware such performance was even possible. Any thoughts ? ? ?  



Neat isobaric (Momentum, Ultimatum) bookshelf speakers have excellent bass for the size. Both can be found used for under 4k. ProAc Response floor standing models also have very solid bass and they sound great with the Wells Majestic. The footprint is no larger than a good bookshelf speaker stand.