If I use a lower powered amp on the top end ( I have a 100 wpc Aragon not currently in use) would that make any sense? I will also have the B&K checked out to see if there are any issues with it, but I'm concerned that sending 200 watts to the upper and 200 to the lower speaker modules is why I'm having the issue.If the problem is amplifier clipping, using a lower powered amp (for either the lows or the highs) will make matters worse, not better.
Also, you are not "sending 200 watts to the upper and 200 to the lower." The power you are sending to each is determined by the music, the volume control setting, and the speaker efficiency, as long as the amplifiers' maximum power capability is not exceeded. And keep in mind that music almost invariably has most of its energy concentrated in the lower part of the spectrum.
Keep in mind also that if you biamp with two different model amps, especially ones with different power ratings, if their gains are not the same you would be introducing a volume imbalance between the lows and highs in horizontal biamp configuration, or between channels in vertical biamp configuration (vertical biamping with different amps of course not making sense for other reasons as well).
I second BDGregory's suggestions about how to go about addressing the problem itself.
Regards,
-- Al