I briefly owned a RS1i and it sounds very different from my RS1 2003. The RS1i in fact sound so different that I'm afraid that if someone heard it, they would believe that it is the representation of the grado sound when it is definitely not. It's not a small difference, and I don't understand why this difference exists. I don't think it's possible that the sound changed that much since 2003. I personally prefer the brighter RS1 much more. For the RS1i, the upper midrange spike has been toned down a lot taking away some of the clarity in the guitars. The bass is boosted to give the user an impression of more dynamics.
I have had a 2008 RS1 with buttons (Sold) , MS-Proi(Sold) and now RS1i (Sold). All of these sound very similar to one another, identical I'd say. More importantly, all of these don't even sound bright nor do they have the upper midrange spike that my 2003 RS1 has that makes guitars and drums sound very real and exciting. Drums and guitars on these RS1i sound just like any other headphone and don't stand out. I don't think I own defective RS1i because I've already owned two other grados (bought from two different sellers from the world) that sound the same. I personally looked at the voice coil (red) and color of the driver (white), and they look the same as the RS1 2008 and Ms-Proi.
The soundstage is the same as a grado, that's where the similarity ends. The treble seems to be lurking the background and isn't as protruding , the midrange sounds full but something about it makes it seem like there is a lack of clarity. The bass while the amount has increased, doesn't sound as tight as my RS1. I'm fairly disappointed in what I've heard, so disappointed that I got rid of it quickly. I clearly remember that my RS1 sounds exactly like the RS1i I demoed from a store downtown but why does this RS1i and the two other grados sound so different? Did Grado have an odd batch?
Now I haven’t given up looking for a RS1i that sounds close to my RS1 so I bought another RS1i. They still don’t sound as bright but they are noticeably better than the other ones I’ve owned, less midrange muddiness. I’m not so sure I should continue looking anymore. Why is there such a big variation in sound?
They really sound nothing like RS1 and previous SR80 and SR225 I’ve owned. At this point, I start to question how many of these “darker” sounding grados are out there. I think everyone should be aware of this because the sound difference is massive while we could technically have the same model. Ever wonder why some people’s impression of the same grado model vastly disagrees with some others? Something just doesn't seem right
My impression of the sound
Grado (SR80,SR225,early ~2003 RS1): Bright, blatant upper midrange peak, tight bass light, crisp sounding. Summary: Harsher raw sounding grado
Other Grados (RS1i,RS1i,MS-Proi, ~2008 RS1) : Midbass presence boosted, overly warm midrange, rounded sounding and not crisp, tamed upper mid spike. Polite but still detailed highs.Summary: A gentle and more lean sounding grado
I'm not going to buy a grado again without being able to audition, no more online grado purchases.