Please tell me what this means in English; in advertising a pair of speakers for sale, the dealer said:
"This speaker does have a combination of somewhat difficult impedance and negative phase angle in the upper bass, just like most loudspeakers of this type and size. These are not a good match for SET-class amplifiers."
These are not oddball speakers but a very respected manufacturer. They are a 3 way bass reflex, with (2) 6" woofers, a 6" mid-range, and a 1.1" silk dome tweeter.