Druid Mk4 08 Kit Comparo

With reprint permission from Mark Lucas

"The Druid upgrade kit shows all the thorough completeness that we’ve come to expect from Zu!!  Well organized shipping, carefully thought out to separate and protect the drivers.  Right down to the slits in the material to hold the wires and keep them off the components.  A video guide to watch before you start is included, along with the necessary screwdriver.  The main message from the video, along with a lot of small but useful tips, is a method to protect the front of the cabinet from damage while changing the drivers.  The wiring lead lengths are appropriately short enough that the driver can’t get very far from the cabinet.  If a second person is available, to cradle the driver while working to separate the wires and driver and then to reinstall the replacement, that helps a lot.

We replaced the drivers in about 15 minutes using two people.  The original drivers have the crossover attached to the back of the HF driver.  So it comes right out along with the driver removal.  The new crossover is a single capacitor and is made up as part of the leads between the drivers.  The drivers externally do not appear to have a difference, so looks do not change.

The leads are made up the same way, before and after the change over.  The wire coming up through the cabinet attaches to the back of the 10.5 driver. A second wire is clipped onto the same point and goes down to the HF driver.  These clip on tight enough that a pair of needle-nose pliers and extra hands to firmly hold the driver while wiggling them off is very useful!  The screwdriver did get a good grip on the mounting screws and felt very secure.  We didn’t have a single case of slipping and scarring the screw head, adjacent driver or cabinet.  Unmounting the drivers consists of removing the trim ring around the big driver, bumping loose the driver from the cabinet.  Unhooking the two pair of wires and removing.  Then pulling the 4 screws on the HF horn and lifting it out.  Unscrew the driver and applying the new.

After standing them up, we set them aside and listened first to the unmodified driver set of Druid’s.  We took a few songs getting used to the usual very fine sound quality of the Druid, in this case driven by a single ended, parallel fed, 300B with about 8 watts.  After getting acclimated, we switched to the modified version pair of speakers.  As seen here….


While setting to one side myself, and not having any stereo sound stage information, I noticed in the first few notes that the sound was a smoother, cleaner sound.  Within another 30 seconds you can confirm your first impression.  Then I moved to centered, to get the full picture and the first thing I noticed was the information seemed a lot deeper and cleaner.  Then you start trying to focus in on HF and lower, trying to localize where the differences are.  But it’s not just a cleaner sound from the super tweeters or just from the crossover region into the highs…its cleaner and smoother sounding top to bottom!  Song after song, the depth and newly refined character came through!

Later in the evening, we stood together side by side both pairs of speakers for a short time, to make quick change of the Zu Libtec speaker wiring for faster back and forth comparison.


Changing over, just seconded the initial impressions of new found smoothness, stage depth and separation of instruments.  If you hear either version separately, it’d be hard to pick apart the sound and identify the differences.  But back to back, it’s clear that the change out complements all the original ideas of the design.  Easy to drive, but higher power capable, dynamic and nimble sound.  Fun music without digging out every bit of harshness that some recordings tip up on some systems.  The focus is on the music and not on the system but certainly capable of revealing the difference in upstream components and wiring changes.


At about a 20% of original speaker price, some could be perfectly happy staying with the purchased system.  The original is good enough to be very satisfying.  But with this comparison, 4 out of 4 Druid owners were pretty impressed with the change over and likely will spring for the upgrade.  Even spouses could hear the change and enjoy the music enough to stretch the evening later than it should have been!


Thanks to everybody.  Especially Ron for arranging and Jeff and Ivy for hosting and putting up with us!

Mark Lucas
Chief Engineer - Knoxville
Journal Broadcast Group