I'm getting quite a bit of confirmation on this, regarding Grado's and ortho's., I thought I was a little nuts when I first noticed my preference for the Grado's. It is starting to make sense to me, and I am beginning to get a little amused at the 'science' debates, particularly because there is more than one or two disciplines in science, and they do not necessarily support the same conclusions.
From a physics/electronics/engineering perspective, the Grado's are indeed 'flawed'. From a psychological/neuroscience perspective, I think they may actually be brilliant.
I really, really do not have time to get into it in detail, but my 225 i's not only correlate to the typical hearing response at low volume, but they also take advantage of the fact that one does not NEED to have the fundamental of a bass note below 80 Hz reproduced in order to hear that particular note. Most professional bass cabinets roll of sharply below 50 Hz for this reason, and yet the open E on a bass is 40 Hz. I play an extended range bass, with a low B at 30 Hz, yet when I play live I have a very sharp 24 dB filter at 50 Hz. My open B rumbles and shakes the venue like an earthquake, even though the tone at 30 Hz is most definitely not present.
I suspect that Grado are a lot more scientific than people realize, but that they are 'tuned' to a different scientific perspective. I'm pretty certain I may be called out on this statement, but I don't have time to elaborate. I am equally certain that there are many Head-fiers who know exactly what I am referring to, but choose not to enter into the endless debates
Grado was never trying to be "accurate", as the graph warriors call it. They say this right on their website, actually. Grado phones are more "art" than science. When I put my first pair of Grados on my head almost two years ago, I was immediately taken by them. The way that they so beautifully reproduced the natural timbre of strings and vocals captivated me. I think those who want a flat FR or whatever have plenty of choices. Grado never set out to design headphones like that to begin with, so to fault them because they don't measure as flat as a Sennheiser is pointless.