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.