RF T112D4 distorting!

Hi there am from the United Kingdom and basically ive bought a used RF T112D4 sub of ebay from the States which was described as used and in great working order tested at Soundtrack etc. Well ive just received the sub few days back and ive got a JBL BP1200.1 amp to use (yeh i know its way overpowered but i figured that ill have to control/adjust the gain carefully + these subs should be able to handle a bit more then their rms) Anyway i asked guy the who i brought it from that did they run it in and thay and he goes for a few hours but recommended that i mite aswell play it at low volumes for about a week. I also phoned RF Tech Support in the States to confirm this and they said shouldnt really need to break it in just play it low for a few hours then do what you have to do power it etc. So i had a ported box which was about 1.75cu.ft without the sub and had a port 4"wide and 4"long i knew the box will be a bit small etc but i just wanted to try the sub in it see what it sounds like then i thought ill keep the gains really low let the sub break in for a few days while i sort out a proper box.So i started by wiring the sub into 2ohms by getting one wire from one +voice coil and plug it in the other side + of the voice coil and vice-versa or the -voice coils. Then from one side of the subs voice coils -&+ i had a wire put into there and the other side going to my connectors in the box and mounted the sub into the box. Then i put the box into me car and from the outside of the box i connected a wire to +&- and then to the amp. I switched everything on and the sub sounded fooked/distorting/farting i cant explain it i was gobsmacked. There was just no bass at all!!!! I then took out the sub from the box to try it just incase the box was too small or somin and still no difference, so i wired up one side of the sub/voice coil and tried it still no good. I even tried it with a way underpowered amp that am using with my speakers and still it was no good.So i phoned RF Tech Support in the US and they guy couldnt really help me over the phone, i did like turn it up etc so he can hear but you really cant tell over the phone and he reckons maybe the sub is faulty/damaged spider gone etc (so am ****ting me loads now.) The guy goes ill have to ring my RF Distributor in the United Kingdom, so i rang them the next day and same again he couldnt really help me only recommended that i go to a local car audio shop (since they didnt have a RF dealer in my area) and he goes yeh if the sub is gone and it needs reconing (what ever that is) etc its gonna cost me in excess of £100 (****) but he reckoned that the sub shouldnt be blown probably just some minor settings or soming.So i went to a local car audio shop and they guy didnt know much but did have a multimetre and said well the voice coils are ok (btw we are now testing the sub with the small amp not the jbl) and i tried a basstube from his shop and that sounded all ok. So i went to another shop that sells car audio, parts etc and the guys go change your earthing which i did but still no good. Then he got a sub in a box and we tried that and that sounded ok so he reckoned the sub is gone!!!!! I was about to cry so i just hooked my speakers back to that amp and they sound ok and taken the sub out and put it in me room now to get some answers from you lot hopefully.So:1.) I did wire the sub properly yeh when i put it on the jbl amp @2ohms?2.) What could the problem be and whats the chances taht the sub is blown?3.) If the sub is blown could i have blown it or is that i was sold a dodgy one?4.) Whats reconing etc?I hope there isnt nothing major wrong with it and there is a solution for this if not then ill be screwing and wouldnt know what to do.I hope you lot can help me!!!!Cheers