Like your other recent questions, this presumably refers to Metallica, and must be describing the band's eponymous fifth album, which marked a deliberate change of direction and style from very fast, aggressive thrash metal of their earlier work. As this passage says, the songs are shorter, slower and simpler.

I presume "down-wound" means "wound-down", which is the opposite of "wound-up"; whereas "wound-up" conveys the image of a tightly coiled spring, and means tense, frenetic, highly energetic, "wound-down", or "down-wound" as here, is the opposite. The songs on the "Metallica" album are hardly relaxed, but they are relatively less tense, less "wound-up", than what went before.

It's difficult to pin down what the writer means by "directive". A directive is an order or instruction. Perhaps it means that the band had, as it were, ordered itself to adopt a new style. Perhaps (and I suspect this is the case) the word is being misused, and what the writer really means is "direction", in the sense of tendency or style. At any rate, it evidently refers to a deliberate intention to give the album this character.

If the songs are more laid back than before, it seems strange to say the the listener is "pummeled" by them. Evidently a distinction is being drawn by the reduced tension of the songs themselves and the intensity given to to them by the style of production.

http://en.wikipedia.org/wiki/Metallica_(album)