Polk subs aren’t bad from an accuracy or sound quality standpoint, they just suck for home theater simply because they lack decent extension. When I owned a psw 10, it sounded just fine with music.
If you follow Dolby’s cinema specifications, a subwoofer should have a minimum response down to 31.5hz -3dB, if you follow THX, 22hz. There is no excuse for a 10” subwoofer to not be able to reach 30hz, and a 12” sub 25hz. Even the extremely cheap Dayton subwoofers manage this.
In addition, the amplifiers used in their subs are awful, and poorly mated to the driver. The Dayton sub 1500 may top out at 150w, but this is more than enough power to drive the sub past its mechanical limits, the psw 10 starts clipping at a lousy 95dB @1m.
I do agree though. A good speaker or good sub should sound good with everything. The only reason a sub or speaker would sound good for one type of content but not with others is because certain things may hide flaws.
The whole “musical” or “fast” subwoofer debate mostly has to do with group delay. Music exposes these flaws because our brain is accustomed to what a bass line should sound like, for example, but not necessarily the rumbling lfe in movies. So called “musical” subs generally tend to be sealed, which can sometimes reduce extension, making them not as effective at HT. If you took two subs that had identical extension, and one was accurate with a lack of excess group delay, resonances, or “humps” in the response, and one with the problems mentioned above, the accurate sub would sound equally good with movies and music.
