It seems to me that my biwired KEF 104/2s are just a bit more transparent when the crossover is set to 80 Hz. They also sound fine full range without the sub, but the low pedal notes of a pipe organ, for example, are missing. The HGS-15 fills that in, and can provide that subtle more felt than heard experience when a big pipe is invoked. For HT, you really need the sub; for jazz and chamber music, my favorites, maybe not.
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