So I finally got around to modifying my parts express amp to the 24 db/oct. rolloff per John K.'s web site. The modification only involved the substitution of 4 components and only took me about 30 minutes- very easy job,especially for one with soldering experience. This amp is used with my sealed 122L tempest sub, and I'm about 80% music/ 20% home theater. The results are promising so far; I have much less mid-range bleed through than before, and the sub is more "invisible" than before; very important because it is being used in our living room, and my wife insists that the sub is hidden behind the couch (primary listening position). A few notes: - even with a 24 dB/oct slope and crossover set to ~70hz, male vocals come through. Much quieter now than before, but still enough to notice. - the only chance my sub has at being truly invisible to my ears is by positioning it very far away from the listening position. That way the relative volume of the midranges will be weighted more towards the monitors that are supposed to be playing them. Another thing- I've noticed that I have strong output at 40 Hz, greatly reduced at 31.5Hz, and nearly nothing at 20 Hz. Obviously no bass boost involved here. Frankly I don't really miss the low extension- but I'd be curious to know if this is consistent with the experience of other sealed tempest users in the group. Lastly- how do I post pictures in a message? I just finished some sound clearing house monitors that I wanted to brag about.