Define small, tight, musical. Small is kinda easy, but measurements help. Tight is a strange word as is musical as they're completely subjective and vaguely defined. How does a sub match a Kef brand speaker? Personally I'd say keep the Dayton and save some money for a better sub, i.e. one capable of significant output (so you have sufficient headroom for now and the future) and/or extension (i.e. how low a frequency it can capably reproduce within a small range of the rest of the frequencies it can reproduce). But that's just me.