that should be the N4, if you check their website descriptions
"The Noble 4 is a neutral sounding product designed to appeal to those who desire a flatter frequency response. An update from the Wizard’s original four-driver design, the Noble 4 lacks the controversial dip in the high frequency region. The smooth, flat, sound makes for an ideal pairing with vocal, acoustic, and classical music."
N6
The Noble 6 is an adaptation of the present four-driver design. With the addition of two unique drivers, the low-end is considerably filled out while soundstage has expanded building upon what is already a natural, airy, space. Mids and highs were not disregarded in the design process either, the Noble 6 is characterized by smooth mids and highs with great extension at the top end.
Relatively, the N4 is more neutral. N6 and K10 would be better described as balanced imo