@grislybutter "254 Hz is middle C! 350 Hz is well into the mid range. RAISE THE CROSSOVER POINT for the subwoofer" The Nautilus 804 has no subwoofer, just 'woofer'. And small ones to begin with, so 350 Hz does NOT sound like a very high frequency for a 165mm cone (in fact the true MIDRANGE speaker has about the same size !!! playing all the way to FOUR THOUSAND Hz!)
And messing with the crossover of a fairly successful commercial speaker is "dangerous" IMO. The I'd rather do a full DIY and safe a few thousand dineros.