Ive had a chance to play with a Ns15....
I got it with ripped spiders, so i just glued them back on the best i could, lasted a few hours.... decided it was time to have a bit more fun... wired i down to .5ohm on my AQ3500.1 (new style) in the box...took it no problem... was a bit noisy due to torn spiders but.. still worked! after a while of trying to kill it in a box.. full clipped signal, i took it out and free aired it fo another 15min... still at .5 on the AQ... i got board and decided to cut it up...
basiccally what im saying is the NS will take quite the beating!!