Like Spoiler, and as I've said before, I can drop my cheap Sony into my huge room and hear "punch". By punch, I mean the initial attack of the stick hitting the skin of the drum or a bass string being released. This initial attack has a rise time of 5 to 10 milliseconds which puts the frequency at 100 to 200 Hz. The 600 has no hope of reproducing this with its 100Hz brick wall filter.

Is this attack any better for those that are using the amp that has the 150Hz filter?

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated