I have a few pairs of them and sold lots back in the day. The range was NS-5X, NS30X, NS100X, NS300X, NS700X and NS1000X. They are built well, sealed cabinet, use the carbon die cast bass driver and mid and a nice little dome tweeter. They are tight and bright but in the end, they are horrible for anything except Japanese harp music. Quite honestly, I love the look (mini NS1000X) but they sit unloved in my storeroom gathering dust. They actually used to sell here at $1399 per pair back in the day.