coustic 241se crossover ?

i have two 70watt rms kevlar svc mid subs wired in series, briged mono mode for 8ohm load. the rca plugs were connected to my sony cdx-ca890x sub out mono plugs, and then to the input rca on the amp. at this time all filters hi -low were set to off in the head unite loudness to off also, i also set the fade to full rear, and the amp to lpf, the sound was muffeled like a pillow was over the speakers, i played with the high-pass/low-pass frequency control workes between 30 to 300hz also the input sensitivity control and bass boost to no avail still sounded muffeled so i switched to full range mode it sounds better, but without much bass midrange response which is what im after, so i pull the head unite and plug the rca pluges into the audio out rear off the head, i turn it on set to lpf on the amp muffeled sound again, i try to ajust the sensitivity and frequency no good, im starting to think the amp speakers are not compatable, so as a last ditch effort i switch the amp to hi/pass filter on, every thing changes, no more muffeled sound, instead i hear mid range/bass notes clearly, all off a sudden it sounds a hole lot better, but why?the filters  seem to be working in reverse! or is the high pass filter ment to fliter out h.f.sound, i thought it was the other way round, if any off this makes sense could someone say what ive done above is the correct way to connect amp to head amp to speakers. thanks Geoff. 

Geoff,

the muffled sound you described is probably because you had the amp set to low-pass, so the higher frequencies were cut- subwoofers aren't meant to play these frequencies.  The sub out on your headunit probably has a low pass filter so that it only provides bass information, so it sounded really quiet when you set your amp to high-pass.  Then when you switched to rear outputs and noticed the difference.