Anyone who knows me knows I am a fan of Zu speakers so I will not claim that this is an unbiased view of the upgrade. That being said, I know Zu will be offering an upgrade path in the near future for Definition owners. I am fortunate enough to have had the drivers changed in my room right after a listening session with the original drivers so a "side by side" comparison could be performed.
First, let me tell you why I have been so smitten over the Definitions for years now. Some of the attributes that the Definitions are known for are amazing tonality, great macro and microdynamics, and a very cohesive presentation due to the crossoverless design. I would submit that most people's negative impressions of Zu speakers are do to improper setup and component matching. In order to extract what is capable from the speakers, they require careful setup. As far as component matching, I really haven't heard anything that sounds bad with them but there are certain associated equipment that sounds amazing with them. The great part about component matching is that they don't require 400 watt amps to make them sing. A well designed, yet inexpensive, 2-25 watt amp can bring a grown man to tears with the Definitions.
Installing the drivers was actually quite easy and could be accomplished by any owner willing to do it. The drivers I purchased already had 1000 hours of burn in so break in wasn't an issue for me. The difference between the drivers was not subtle and demonstrated a quantum leap forward in transparency. I honestly never thought the Definitions had a lack of transparency...until the Dominance drivers were installed. Articulation and reverberation of individual strings was easily apparent. There was a "see though" presence in human voice without bringing thinness to them. So, transparency dramatically improved without sacrificing the killer tonality that Zu lovers are accustomed to.
Also, the efficiency of the Dominance drivers is higher than the Definition drivers allowing less range on my preamp knob to reference levels. Apparently, impedance is now an 8ohm load rather than 6 in the original version. With this, both microdynamic and macrodynamics are improved. How much is related to the increased efficiency vs how much is due to the updated drivers, I don't know but I could never go back now that I've lived with it.
So, overall, this is a significant improvement to any Definition owner. Apparently they will be offering an upgrade path to rebrace the cabinet, change out wiring to Zu Event wiring, rework the tweeter, and update the bass amp if needed. Keep in mind my only change was the drivers and can say I would recommend the upgrade to anyone that loves their Definitions and can't bear the thought of letting them go but would like to move up the upgrade path.
David
