I've lurked on this thread since the page count was back in the two thousands. I've found the listening impressions here both useful and interesting, so I wanted to give back with some reflections on what I've heard. (This'll be a ramble!)
Ideally I'd have just one pair of headphones, but I'm hanging on to two: Joe's HP-1 and John's PS2000. (Plus a pair of Etymotics ER3XR.) I've been through a lot of Grados - 80i, 225i, 325i, 325e, GH4, GS3000e - and some other makes - Stax SR-5, AKG K702, and I've heard HD600s, HD800s, Sundaras, and a few others.
I've cast my lot with Grado in part because I'm fussy about how things look. The HP1 and the PS2000 have a mature, functionalist vibe - they could hang out in Paris - whereas I'd want to hide, say, the HD800 ear Lamborghinis in a drawer.
But mainly because of the sound. The GS3000, the PS2000 and the HP1 are, in my opinion, qualitatively different from the rest of the Grado line. The 50mm drivers do something special - the midrange and the treble (oh, my god) is spotless, and the dynamics and sense of space are incredibly vivid, and they can get to "live" volume levels with perfect composure. The famous drivers in the HP1 are just as spotless, but they lack the elevated midrange that gives John's Grados that "magnifying glass" effect, they don't sound anywhere near as dynamic, and they lose some definition when played too loud. The PS2000, I would say, is better than the HP1 in every way except tonal balance. Compared to the HP1, the PS2000 and GS3000 midrange can sound thin at low volumes. The HP1s sound calm and exact, with a subtle emphasis to the lower midrange, and really solid bass (when you get the clamping pressure right). It has what I'd like to call a "broadcast" sound - the qualities that jump to my mind are how rich and clear Leonard Cohen's voice sounds, and how noises like rain falling on a tin roof, the snap of a camera shutter, sound real beyond anything else I've heard. The presentation of the HP1 is holistic in a pretty special way. When well driven, fine details of the recording are there for you to hear, but don't draw your attention inappropriately (to be clear, this isn't a euphemism - they're extremely detailed). They make it easy to comprehend the music you're listening to. I find that to be a rare quality in hi-fi, basically independent of sonic quality, probably mainly a matter of frequency response and mastering. If I'm hearing a song for the first time, I might understand it better on my laptop speakers than on the PS2000e. The HP1 do well by that metric; maybe not as well as the Etymotics buds.
Back to the 50mm drivers - to me, the GS3000 and the PS2000 each sound lifelike. I don't say that lightly. I walk by someone playing a drum kit outside, unamplified, and my mind jumps to the GS3000. I hear someone playing an electric keyboard into a grungy amp stack in front of me, hear the layers of rattle and buzz and tone, and I think of the PS2000. It's something surreal. Surely, that has never happened with any other transducer I've heard.
The GS3000 have an "open air" balance (if the HP1's acoustics make me think of a radio station's studio, the GS3000's make me think of a music festival) and better texture, for lack of a better word, than the PS2000. Hearing the same drum solo on the GS3000 and the PS2000 - with the GS3000, I notice the flapping noise of the drum's skin, and with the PS2000, I can better hear the "note" of each drum hit. The GS3000 also has this rich, colorful decay - an adjective that comes to mind is "bloody" - that I love. Interestingly, that color went away when I used some extremely high-end DIY amplification (directly heated triodes loaded by nanocrystalline-core transformers, with a permalloy-core autoformer volume control at the output). In that setting, the GS3000 - well, they disappeared.
I sold the GS3000 because the PS2000, despite lacking that texture, has better bass and comes closer to the level-headed sound of the HP1. The treble of the PS2000 is better too, I feel, but it's a toss-up - it can be harsher (I mean, it's also perfect). The PS2000 is more informative than the GS3000; it's hard for me to pin down why, but it's just a little easier to tell what's going on in a song. Against the HP1, the PS2000 gives you several extra layers of sound, space, and imaging. Small sounds coexist with large sounds and have equal energy. The bass is fast and has "bounce" and, when you're listening loud, is just huge. The build quality on my pair happens to be better than the GS3000 I had, too; they clearly picked a good set of gimbals for my PS2000s, where I replaced the gimbals twice on the GS3000. On the other hand, the finish is wearing off on my set, which you might call patina. I read some review of the PS2000 where they compared it to the fading of raw denim; that's some wild spin, but it's easy to rationalize when you're in love.
A couple last notes. Take my impressions for what they are, but especially because I'm not using these headphones most of the time with any fancy setup. I've heard the GS3000 and the HP1 with the peak-of-the-mountain amplifier I mentioned, and I've listened to vinyl on a similarly great setup through the HP1, but usually I'm listening to the PS2000 plugged into my 2017 Macbook Pro and playing Tidal. One can hear the limitations clearly, but I want to enjoy these headphones every day, and I can't be stuck sitting by an amp the size of a small cooler. That said, the GS3000 driven by the triode amplifier was one of the most memorable hi-fi experiences of my life, up there with a few all-horn speaker systems I've heard (Jeffery Jackson's; Austin Acoustics). On price and quality - everyone has different opinions and also different means, but if someone took away my PS2000 and gave me back their MSRP, I'd buy back the PS2000 without pause. But again, the $100 Etymotics are arguably better for music comprehension... and other Grados like the GH4, for example, are excellent in their own ways. (Those sound very spacious, though the midrange was too thin for me.) Finally, I wonder what will come next at the top of the Grado line, though I'm not looking to buy anything else anytime soon.
That's probably enough effusion. Thanks to the posters on this thread for talking me into the leap to the GS3000. I've been listening to much more music in the past year or two because of it.
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