I think when people say it makes them a "whole new headphone", what they are remarking on is the degree of improvement being so surprisingly big, rather than actually making them sound like a whole different headphone.
No mod can trasform a Grado into a Sennheiser, etc. All our mods are doing is taking what is there and improving on it.
The one comment that can mystify me is when I read someone who has not tried the mods say they are perfectly happy with the Denons as they are and believe the mods are a waste.
That would be a valid comment for that particular individual *if they had heard one of our mod-ed phones* and done some good A/B work. If you already love the phones, the mods will just give you more of what you already like and improve on things you may not even have noticed were not fully optimized until you were able to hear a version of the phone that had been corrected.
The other mis-conception is that mods are only for people who find the bass bloated on the Denons, as if bass were the only thing affected and that impact was to truncate, roll, or otherwise lop off the bass of the phones. Again, there is no loss of musical bass information from the mods, nothing is done to thr driver itself. By making the frame in which the driver sits more rigid and damped, it allows that driver far fewer places to release and dissipate that bass energy, except where it is supposed to. The mods will tightend, harden, speed up and increase the impact of the bass. You will lose most of the extraneous, non-musical resonances and vibrations throughout the assembly, and good riddance to that unless you like the woopie-cusion effect and simulated bass impact they provide. We find that effect distracting, causing a loose, flabby bass cloud.
The damping affects more than just bass, it's able to bring the mids forward in a psycho-acoustic sense because the bloated bass cloud is no longer overwhelming the lower mids. The sound is less muddy and more focused. Detail and apparent resolution increase.
Also, the pad mod (and our cups) enhance and expand the soundstage in an easily appreciable way.
Bottom line is we can't make the Denons into a whole new headphone, we can improve solidly on what's already there. If one already likes the Denons, that is not a reason to avoid the mods; they can only give you more and better of what you already like. Bass is not rolled off or softened or neutered; it gets harder, faster and more focused. Finally, the mods effects are not limited to the bass, but impact the whole presentation in various positive ways.