The power (watts) delivered by a powered sub and the subs low end frequency response are two different things. Each powered sub will measure differently in each regard. Some subs go down to 20 hz or less and some only to 30-40 hz or so. More power will generally be needed to produce equivalent levels in larger rooms. Same true with integrated subs. Either approach can deliver similar results.
For audio, the sub should be adjustable so that it can blend in smoothly with the separate speakers. Same true for home theater, but for movie sound effects, etc., you might run a sub at a higher level for extra impact compared to what you would to fill in the low end smoothly for music.
For audio, the sub should be adjustable so that it can blend in smoothly with the separate speakers. Same true for home theater, but for movie sound effects, etc., you might run a sub at a higher level for extra impact compared to what you would to fill in the low end smoothly for music.