Are NHT speakers know for being inefficient?

I know this isn't high end audio but it is what I have now. I actually am using my NHT 1.1 speakers that use to be my rear speakers as my mains. I was using some Carver AL-III with a Phase Linear 400 as mains but that is not the case now. I have since bought and older Pioneer Elite VSX-07TX. Not a bad deal for 162.00. My question is that now I have the NHTs up front. I really have to turn up the volume alot to get them going. The receiver is rated at 110 into two channel and 100 into 5 channels. The speakers are rated at 150 max. I can turn it all the way up and it sounds great, no clipping or any rough stuff. But still not THAT loud. I just can't imagine that these speakers are that inefficient. I am using a Sony don't remember the number dvd/cd/sacd player. It is around 300.00 new. It seems to me I have read somewhere that these older NHTs circa 1993 where on the inefficient side but this is a little suprising. I do notice if I turn them from stereo mode to Dolby Digital or THX they are louder but still not that loud. For normal listening level in stereo mode I am having to turn it up half way. Anybody got anything to say on the subject. I also have done all the adjustments with the receiver, although the vsx-07tx doesn't allow to much user tweeking. I am using optical and analog cables and it makes no difference whether I am listening to vcr, tv, fm. Well actually the optical is a little better but still the same basic thing.
Thanks,
Christopher