Best closed-backs I've heard are Focal Stellia, which cost $3,000. About the only closed-back I've heard that can compete with open-backs in the same price range. Magnificent headphones.

The AKG K371 are a very, very good entry-level closed-back for around $125. Blow away the incredibly overrated Audio-Technica ATH-M40x and M50x in the same price range.

Meze 99 Classics are a lot of fun for $310. Impeccable build quality, comfortable, beautiful. But they are bassy as hell, with flabby bass that bleeds into the mids. Good, smooth treble, though. The 99 Classics are an example of a can that has a hideous-looking frequency response curve but still sound fun.

Focal Elegia are a very good deal at $325 from Adorama. Not worth the $900 sticker price because of the always-sketch Focal build quality and metallic and incredibly weird midrange tuning that almost demands EQ. But their imaging is damn near holographic, and the bass, while not always present, really punches and slams when called upon.

I have not heard the Audeze LCD-XC, but people rave about them. I have owned the LCD-2C and own the LCD-X 2021, and both of those are fantastic headphones. So, I bet the hype surrounding LCD-XC is real.

I owned the Dan Clark Audio Aeon 2 Noire, which are around $800-900 new. Overrated. Blunted transients, lacking detail or dynamics, especially with the felt filters needed to mute the treble peak. Too much clamping force if you have a big head, too, and the Nitinol headband will not bend. Just get an HD 6XX for about $600 less if you're interested in that sound signature unless you MUST have a closed-back.