My settings
Currently, I have my sub setting at 120Hz (max), and my receiver set to 60Hz. This allows the receiver to perform the bass management. There is no reason to set the sub anywhere else, since the frequencies are cut at 60Hz via the receiver. All my speakers are set to small and the sub is set to LFE (as opposed to LFE+Main and the fronts as large). 60Hz is about the most your 7" woofers will reproduce efficiently at normal listening levels. Sure, they'll go down lower, but have you attempted to drive those woofers? Before you get much bass out of them, you need to take the receiver almost to 0 on your volume setting (or boost your lowest frequencies on your parametric eq and turn up the bass control). Your towers handle every bit of a 500 watt amp, and much of that power goes to those woofers. Let them do the "punchy" bass, and your sub handle the rest. Your midbass and mids will sound that much better.