Heya,
The FA-011's are not as bassy to me. They have more mid bass, but less sub bass. I put them right next to the FA-003's, which when amped, have better sub bass to me and better impact (expected from tight sealed closed back headphone). The HTF600's have good impact, but they're practically semi-open. They didn't have the impact of the XB500, DT770 PRO, D2000, Ultrasone PRO 580, PRO900. My primaries are the D5000 and HE-500, which are tremendous with bass and impact. I swap headphones all day every day. The FA-011's are just not that super bassy, the DT990's are more bassy really. And the HTF600's are as bassy as that with good impact, right along the lines of XB500 to me for the most part (sacrifice a smidgen of bass quantity for good mids & treble, good deal to me).
Alas, if interested, check the FA-011 thread(s), I'd rather post there. This thread is turning into a big "I don't have these, nor heard them, but I've read some threads and OMG OMG OMG OMG." I can't take it.
Bowing out. `Night all.
Very best,