I received today an EP175 to add to my system. I connected the EP175 to the receiver and started to do the tests. Originally I had only a couple of Paradigm Studio/80 (excellent sound) and I decided to add a subwoofer. I don't picked the Servo-15 or PW2200 of Paradigm because it was too expensive for my current budget, so I went to the EP175 that theoretically can handle 175 Watts. I tried setting up my Marantz SR-14EX for "small" speakers on front (I only have front speakers) to send some power to the subwoofer, and I tried with Seven Years in Tibet beginning part of the bass tibetan instrument. I was surprised to hear that the EP175 reproduces an anoying medium to high pitch noise when this instrument comes into play. Seamed to be I could not handle the internal air pressure of the quickly moving cone. I tried changing the crossover settings and lowering volume. The only thing seams to help is lowering the volume a lot, and actually the volume is pretty low in my system for this test. I switched back to "large" in the front speakers, and the Studio80s actually is reproducing the low freq better than the EP175 and with absolutely no distortion.
My question is if this is a normal thing to be expected from the EP175 or do I have a failed unit?. Does the EP175 some clear limitation on the freq it can handle properly with no distortion?. Actually the driver in the Studio80 are 8" and seamed to reroduced the bass more accurately than the 10" of the EP175. Probably I'm missing something, but if I'm not and this is a feature of this speaker I'll be really disapointed being this a pure subwoofer.
Thanks for any advice.

Just offhand i would say you have your sub plugged into the wrong connection on the back of your receiver.
You mentioned:
"I tried setting up my Marantz SR-14EX for "small" speakers on front...to send some power to the subwoofer"

Well the subwoofer has its own internal amp. You don't want to be sending it "power" from your receiver at all. Check your connections again.

When I said power I meant line in this case. The sub is connected to the subwoofer line output of the receiver. Actually I tried using also the high input of the sub (I don;t wanted to do that having a line output for sub) and the results were the same. As long as you keep the volume low the sound it's fine, but when the sub starts to show some cone movement (and not really too much, and not violent at all) the distortion starts to appear.

sounds like a bad unit, call axiom. I have the 175 and it sounds beautiful (although it is setup through an LFE line on a 5.1 system).
Kore