You own an HE400i, how does that compare? I've heard it has way more detail than the HD650 but less bass detail and is similar to electrostatics overall. Where would you put that in the equation? I'm surprised the Foster is less detailed because the biocellulose diaphragm should be fast and they appear to have more treble emphasis, but mostly I am just frustrated to learn they aren't what I'm looking for since it seems to measure similarly to the DT1350, which I like, so I was hoping it would be the perfect medium.
My favorite headphone I've tried to date is probably the SR-Lambda normal bias but it's a bit thin in the bass compared with what I want and VERY open. Maybe I should get another pair of those and call it a day, they really are good sounding to me, although my friends who've tried them and the HD650 think they sound like $20 headphones by comparison. I don't have an appropriate amp for the HD650 so maybe that's what I need... but it feels too "lush" and distant even beyond the resolution and treble being very recessed. It's not even that it's low resolution, because complex passages don't get out of control, but that the acutance isn't as high if that makes any sense. Too smooth. The Stax is surprisingly harsh, maybe too much so.
well, let's be clear here as well. I think in some ways you are mixing up treble emphasis with detail. When I say detail, I mean ability to resolve due to low distortion and lack of ringing, independent of frequency response. The DT1350, in those terms, has less detail than the HD650. The HD650 can sound "less detailed" because it doesn't have as much treble emphasis. However, the detail is still there, it's just not shouting your face off at 10kHz. The HD650 is one of the most detailed headphones there is in terms of ability to retain and not destroy detail through transducer insufficiency, only surpassed by the very top end flagships, but it is also smooth and doesn't force the detail in your face. That being said, Stax detail is on another level, AND ALSO treble pushed, so it sounds crazy analytical.
The THX00 has very, very good detail for a closed headphone. But it just isn't on a Stax level with regards to detail or even a HD650 level.
The HE400i has about the same detail as the HD650, but is more "up front" in terms of presentation. The HE400i is also a little bit better than the HD650 in very dense passages with a lot of simultaneous hard transients. The HD650 has a bit more "weight" to the decay, which can be both good (it gives music more body) and bad (it can sound congested in heavy transient dense music).
So, yeah, when you asked about a closed headphone with Stax level detail, but HD650 (or better) bass, well, that just doesn't really exist. However, I think it looks like now you don't necessarily need Stax level detail, you want a more "upfront" approach with bass, and at least good detail and a v or u shaped signature. In that regard the THX00 fits pretty well. The THX00 would probably be an improvement for you over the DT1350. I'd recommend upgrading your amp and getting SOnarworks for your HD650, and you will be shocked at what the HD650 is capable of with a better amp and professional quality calibrated EQ.
