Hi, thanks for your interest.
yes I contacted NHT, via email, but they didn't answer me.
NHT 1.1 is a fairly old product, so I doubt it can find the replacement driver. The only way is to buy a full 1.1 speaker on ebay, as I couldn't find the midwoofer alone. The problem is customs duties, which cause costs to rise significantly. (in Europe there is no trace of speakers or components similar to what I am looking for, only USA, JAPAN and CANADA)
Regards