Are most people saying the soundstage is crappy just comparing them to open-back headphones? I mean, I would just assume that no closed-back headphone is as good as an open by nature.
Does anyone have any input of Oppo PM-3 vs...
Mr. Speakers Alpha Dog
Shure SRH1540
HiFiMAN HE-400i
Senheizer HD600
Sennheizer HD650
..?
Out of those headphones, I have heard the PM-3, the 400i (which I own), and the HD650. Since it seems like you've also heard the Shure SRH940, I'll throw that into the comparison as well.
For soundstage, I would actually say that the 400i has the biggest overall soundstage in comparison to the other three headphones that I mentioned. (Though one has to keep in mind that the soundstage of the 400i is somewhat small compared to other open-backed headphones). The SRH940 is probably a bit wider in its soundstage than the 400i, but it has noticeably less depth. The HD650 is slightly less deep in its soundstage compared to the 400i, but width is significantly less. The PM-3 is definitely less wide in its soundstage than the 400i, but depth is almost comparable. In fact, I'd say that the PM-3 soundstage is kind of like the HD650, except that it's actually a bit wider and sounds are more separated than the HD650.
For imaging (clearly locating where sounds are coming from), I would have to say the 400i does the best job here. It not only precisely locates sounds to the left or right, it also somewhat gives you the locations of the sounds being closer or further to you. The PM-3 does left-right imaging equally well as the 400i, but at least to me everything sounds like they're the same distance away (kind of like a flat wall of sound kind of thing). The HD650 actually images left to right decently, but I really don't like how sounds can get kind of smashed together because the soundstage is small and a bit claustrophobic. I can't really tell you how the SRH940 performs here, because for some reason I can't really remember anything about the 940's imaging.
In terms of overall sound signature, I would say that the SRH940 is by far the brightest, followed by the 400i (which is already much less bright than the 940), then followed by the PM-3, and the HD650 is the darkest.
Starting from the bass, I believe that out of the 4 headphones, the SRH940 has the most uncontrolled and bloated bass. The HD650's bass is definitely better controlled, but still I think it isn't as well controlled or goes as deep as the PM-3 or the 400i's bass. Both the PM-3 and the 400i have nice, solid bass that isn't flabby and is quite textured (you are able to hear detail in the bass better). Between the PM-3 and the 400i's bass, I personally think that the 400i is slightly better in quality, but the difference isn't huge.
As for the midrange, the SRH940 is most the unremarkable here out of the 4 headphones. I don't think it's that bad, but I really can't remember anything special about it. The HD650 and the 400i both have great mids, as vocals really shine on both headphones. The PM-3 also has some great mids, with its slightly elevated mids making some vocals sound really powerful. The HD650 has the darkest (thickest sounding) mids, with the 400i being somewhat brighter, and the PM-3 even brighter than that - but really, the differences in tonality between those three headphones in the mids is not too big.
As for treble, the SRH940 is most prominent here, but it's a bit shrill to me and is sometimes sibilant. The HD650, PM-3, and the 400i are not sibilant at all. The HD650's treble is the most rolled off (and is somewhat off-putting to me, because I listen to a quite a fair amount of music where treble is needed), with the PM-3 being less rolled off, and the 400i being the second brightest next to the SRH940 (the 940 still being much brighter). I personally think that the 400i handles treble the best out of all of these headphones, with the PM-3 coming in second (I like the quality of the treble, but would like just a bit more) and the HD650 (too rolled off for me) and the SRH940 (too shrill) coming in after that.
A short note on comfort. SRH940 comfort is only ok, but not excellent - it's not extremely heavy, but it does tightly clamp your head a bit and the pads aren't the most comfortable things in the world. The HD650 is pretty comfortable - good pads, it's not even close to heavy, and it doesn't clamp your head very tightly (though the one I did listen to was already used for a while - I've heard they clamp kind of hard out of the box). The 400i is pretty comfortable - it's a bit heavy compared to the others, but the pads are very comfortable and the headband does an excellent job of distributing the weight around your head. The PM-3 is also pretty comfortable - doesn't clamp too hard, it's somewhat on the lighter side, and while the pads are comfortable they're not extremely breathable and so your ears can get a bit hot after wearing the headphones for several hours.
Overall, out of the 4 headphones I mentioned, I prefer the 400i and the PM-3 the most. If you want the best for gaming, anime, and movies, to me you'll want the headphone with the best imaging and the best soundstage, as well as something that has good quality bass to really immerse you. For that, I would recommend the 400i (biggest soundstage, excellent quality bass, and among the best imaging out of the headphones here) and the PM-3 (soundstage not as big, but still decent and has really good quality bass and has great imaging).
Whether to choose the 400i or the PM-3 really depends on what you're looking for in a headphone. If you want something that is somewhat easier to carry around, doesn't leak sound at all, get the closed-back PM-3. If you don't really care about the portability factor, get the 400i. Of course, there's the price difference too. I won't say too much on that except that I think the PM-3 and the 400i both are definitely worth their asking prices.
The HD650 is good if you want a more lush and romantic tone to your music, and if you want to be able to listen to music for hours and hours without any hint of fatigue. The SRH940 - well, I think you can tell I don't think of it very highly compared to the other three headphones.
