A week ago I first got to hear the LCD-4. That was under less than ideal circumstances and I posted my very high level impressions
here.
Yesterday I got to listen to those same headphones on my own rig at home, after the dealer had spent the week breaking them in. This was a much more suitable comparison, again involving my Abyss, HD800S and LCD-2.2c. While I am going to take the weekend to listen more before posting detailed impressions and comparisons (and pictures), I'll say a few words now.
The initial comparison was done using Tidal via the digital out on a Sonos Connect into a McIntosh MHA100. The rig I use at home currently uses Roon (TIDAL and local lossless files) to an Auralic Aries feeding an Yggdrasil via AES/EBU into a Ragnarok and then balanced out into the various headphones.
When I came away from my first listen the LCD-4 were clearly very good, but not so good that I'd have taken them over my existing LCD-2.2c even if I didn't already own the Abyss AB-1266. As a result of listening yesterday and this morning I have decided to add them to my collection along side my Abyss and HD800S etc. These things really do need to be broken in and fed with a suitably potent amplifier.
I would still say the Abyss has the better soundstage, still sounds faster and is a more visceral and "fun" listen. However, the difference is mostly in terms of signature preference and there are areas that the LCD-4 is clearly better to my ears. It's smoother, darker and more euphoric/seductive in its presentation. While both headphones have a similar notch in their frequency response from 4 KHz 8 KHz, I find that more obvious in the LCD-4. Bass is comparable unless you run the Abyss with no seal, in which case it is still clearly the headphone to beat in that area.
I'll have more details to follow, as well as having my new WA5 LE available to test with early next week, but at this point I think both sets of headphones have a valid and complimentary place in a high-end head-fi setup. Both are good enough to listen to anything with and not have any real issues, so its more about mood and flavor. Just to put the cat among the pigeons, with all that said, if you told me I could only have ONE headphone for the rest of time ... I'd likely take neither and go with the HD800S instead!