I wanted to give an update to my journey looking for after market pads now that I've arrived at my destination.
So I tried the perforated ZMF Ori, the suede ZMF Eikon, the Dekoni X00 Elite Hybrids, and now the perforated ZMF Universe. My goal was to find a pair of pads with ear cavities that would allow me to naturally, haphazardly, and comfortably put the headphones on while preserving the tonality and technicalities of the stock Sundara.
I found that both the Ori and the Eikon shrunk the stage but sharpened the imaging, like how one can see things more clearly when they are closer. Unfortunately, this also had the effect making the treble a bit too hot for my tastes. Additionally, I noticed that the bass became a bit more bloomy and wooly with both pads, so I sold both of them shortly after trying them.
The X00 Elite Hybrids were actually a mis-delivery from Dekoni when I actually ordered the TH-900 Elite Hybrids. Tal from Dekoni, though eager to help, never actually shipped out replacement pads even though he claimed he did (it's been over a week, tracking to this day has not updated, I live in an adjacent state, and Tal has gone completely silent in our email exchange). I tried the X00 anyway and it was just poor pairing all around. I didn't listen to them long, but what was immediately clear was that the bass through lower midrange were greatly muffled and distorted.
Noticing that Sundara's stock pads have a round 55mm diameter ear cavity, I had a theory: the muffledness I heard in the aforementioned pads was due to their ear cavities being smaller than 55mm along at least one dimension. This meant that part of the pads blocked the diaphragm when the stock pads did not. The X00 pads were especially egregious of this offense.
I decided to try the ZMF Universe due to its large ear cavity, whose width is the same as the diameter of the stock pads' ear cavity and whose length is 50% larger. These pads do not block the driver diaphragm. I tried them on, and indeed bass resolution and performance was the same as the stock pads, just slightly more elevated, likely due to the better seal of the lambskin vs. the velour.
However, I noticed that, similar to the Ori and the Eikon before it, staging was much more intimate, imaging was sharper, and sounds were much more in-my-face. The beautiful expansiveness of the stock sound was gone, and once again the intimacy sometimes made the treble a tad too glaring for me. How could this be?
Looking over the Sundara's stock pads, I noticed the inner ear cavity wall is very densely perforated and also thin. This meant hardly any inner pad reflections were happening with the stock pads. Following this theory, I placed two strips of 1.5cm x 8cm felt tape along both sides of each Universe pad's inner wall. These walls are quite a bit thicker and rather sparsely perforated compared to the stock pads.
After this mod... Voila! This dampening, similar to how I modded my old M1060's stock pads, more or less eliminated inner pad reflections. The result is that higher frequencies were no longer amplified by reflections to immediately in front of my face and the delicate expansiveness of presence and treble returned! There is absolutely no glare or hotness now either!
For those who love the Sundara's stock sound, but want something with a larger, more forgiving ear cavity, I highly recommend the ZMF Universe pads with my felt tape mod. The end result is the stock sound, slightly weightier lower end, and happy ears. It's been a rather long journey for me, but I'm glad I found a satisfying conclusion.
