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

@audiotroy:  Actually, I don't enjoy trying/buying gear over and over, unlike some audiophiles I know!  As I don't have a huge budget, but have very "picky" ears, I find the process quite stressful. There are no stores in the Sacramento area that offer home demos. I'm not sure whether this is the case in San Francisco, which is  2.5 hours away. Alas-- flying to NY is not a practical option for me!  Thanks for the further explanation re: in-store demos, though. 

Watkins Stereo GenFour speakers for 2k are  very good.

Late follow up. . . I bought an Aqua La Voce DAC, coupled with Empirical Audio Synchro-Mesh re-clocker and coax cable, which made me realize there's nothing wrong with my speakers!  The system, as it was configured before, simply wasn't doing justice to the speakers. Now,the bass is amazing. Round,  punchy. It goes without saying that it varies from one CD to another, but, overall, the improvement is huge. The La Voce is available with different boards/chips (see their website) but as it happens, the standard board is particularly adept at bass reproduction. This was  valuable lesson. 

 No love for Sonus Faber?

I build all of my own stuff, so I'm not much help on what is out there,  but I can say that I would seek out an MTM.... Double the cone area moving air does make a difference.  Good Luck,  Tim