So I had the chance to pit the Expanse vs the Stealth, and I'm going to say it up front: I'm Team Stealth
Yes, I said it, and yes, it's my opinion. I know I'm probably in the minority, but I don't feel the Expanse is different enough from the Stealth. Yes, it's open back, but it's not a night and day difference vs. the Stealth when it comes to soundstage. I think that's more a huge credit to DCA for creating such an "open" closed back headphone rather than a deficiency of the Expanse. I've seen some people comment that the Expanse is a good complement to the Stealth, but I don't feel that's true. A good complement to Stealth would be a true open back headphone that provides more of a contrast like a 1266, Final D8000 or Susvara where they're incredibly open, wide, and less reference tuned.
Before I go into the sound impressions, my chain is as follows:
PC --> Holo Spring 3 KTE --> Loki Max (both in EQ and Passive modes to test) --> Ferrum OOR + Hypsos --> Ampsandsound Nautilus
Much like the Stealth, the Expanse pairs well with a good tube amp to give it that extra "flavor." However, both sounded great just with the Ferrum stack. A powerful solid state can drive these well, but again, you need a powerful amp otherwise the dynamics will be lacking on both headphones. Much like any other headphone I threw at it, the Nautilus of course drove these headphones to perfection.
The Expanse definitely is punchier with the bass bump in its tuning, however, at times this comes at the cost of vocals and overall clarity. Some songs sound a little canned or veiled, especially in rock tracks, while others sounded fine. I felt vocals sounded better on the Stealth vs the Expanse. Ironically, the theme song to the critically acclaimed show "The Expanse" sounded better on the Stealth than the Expanse!
The Stealth benefits from a better sub-bass response, and honestly, with the right chain, the bass is not lacking vs. the Expanse. When I spoke to Dan at Canjam SoCal, he said that some people prefer the Stealth over the Expanse because of the sub-bass. I feel the Stealth has less punchiness (but not by much), but the bass is tighter and clearer. It might have to do with all the damping in the Expanse which doesn't fully allow the bass to "breathe" so to speak. I know that's not a scientific explanation of air moving, but I like the description.
In terms of isolation, I was pleasantly surprised how much the Expanse actually isolated vs other open backs. However, if isolation is something that is important, you might as well just stick with the Stealth. In my opinion, if you're going open-back, you want the full open experience in a quiet environment. The extra isolation of the Expanse vs other open backs might be marginally useful if you have low-level background noise like an AC hum in the distance or something and are trying to listen at lower volume levels.
Now - when you EQ - things change a bit. By adjusting the Expanse to the Stealth's FR, clarity and vocals improve. However, if you need to EQ the Expanse to sound like the Stealth, then you might as well stick with the Stealth, no? As I mentioned before, the Expanse DOES sound more open than the Stealth, but not by much. Again, not a night and day difference. Imaging, detail and separation are both incredible on Expanse and Stealth, and are on par with each other. I'd honestly rather just EQ the Stealth's bass up for the extra punchiness if I need it. Both headphones respond to EQ very well.
Overall the Expanse is an excellent and beautifully designed headphone all around, and I liked it. However, I feel DCA chose a half-measure, when they should have gone all the way. I think if DCA (
@mrspeakers ) wants to do an open back headphone with the incredibly promising AMT technology, it needs to go all the way. If it wants to create a "fun" dynamic headphone (both closed and open), then it also needs to go all the way beyond just a small bass bump.
I would absolutely love to see a balls to the wall fun headphone (that obviously wouldn't be called Stealth), and then a true open back headphone with less damping and less isolation to really open up the soundstage. The AMT has so much potential, and I'm very excited to see what new headphones DCA comes out with in the future.