Which headphone is "best" is always subjective, and depends on a listener's tastes and intended use case. Here's some info that may help you decide which headphone is best for you:
The LCD-2 delivers audiophile quality, low-distortion sound that articulates the power and nuance of your favorite music. Continuous evolution and the addition of Fazor Technology has enhanced its transparency and overall performance. 70 ohms impedance.
The LCD-2 Classic comes with special glass-infused nylon rings, and features the wonderful, warm and laid-back sound signature of the original 70 ohm LCD-2 pre-Fazor drivers. A little more spacious sounding than the LCD-2 but with less specific imaging.
For the LCD2 Closed-Back, we’ve taken the very popular LCD-2 Classic and developed a special sealed earcup for increased isolation. Still has the slightly warm tonality of the LCD-2 Classic, but has a stronger bass presentation due to the closed back. This is very similar to the sonic differences between the LCD-X and XC. 70 ohms impedance.
Many say the LCD-X is the most neutral of the LCD Collection; they’re used by sound engineers and musicians to create the most accurate recordings. They do a great job of translating your mix to the real world. The X and the closed-back XC are sensitive enough to be driven directly by portable players like iPods, iPhones, and some of the better smartphones, but you’ll enjoy better sound with an external amplifier. Its impedance is 20 ohms.
Sharing the same transducer design as the LCD-X, the closed-back LCD-XC offers all the benefits of a planar magnetic design with increased isolation and greatly reduced ambient noise for a private and powerful listening experience. The XC remains far and away the best-sounding closed back headphone available, a truly immersive listening experience. Its impedance is 20 ohms.
The LCD-3 is a high-resolution headphone that always sounds musical and spacious, with powerful bass, an engaging midrange, and an extended top end. Its rich, vibrant sound has real scale and authority. It features a deep soundstage and reveals music in a very ambient way with exciting transparency and detail. You’ll find yourself emotionally connected to the artist and music. Pair it with a high-quality headphone or integrated amplifier for best results. Its impedance is 110 ohms.
The LCD-MX4 is significantly lighter than other LCD models due to our use of magnesium, carbon fiber, and our highly efficient Fluxor magnets. A perfect combination of the LCD-X and LCD-4 - it has the easy-to-drive diaphragm and voice coil of the LCD-X combined with the 1.5 Tesla magnetic force of the LCD-4. It has a different soundstage than the LCD-X or LCD-4 to help simulate a room’s sound, and the sensitivity to be easily driven by any high quality headphone amp, mixing console or audio interface. Impedance is 20 ohms.
The LCD-4 is our flagship headphone - the first reaction upon hearing them is often shock at their extreme spaciousness, powerful bass (flat to 6Hz!), rich and engaging midrange, and open and extended top end that makes music come alive. It features ultra-thin 0.5 micron diaphragms, Double Fluxor Magnetic Arrays that nearly double the magnetic flux for perfect driver control and near zero distortion. Pair the LCD-4 with a high-quality external headphone amplifier or integrated amplifier of at least 1 watt output at 200 ohms; the more power the better. Its impedance is 200 ohms.
The LCD-4z is the easy-to-drive younger brother of the LCD-4 above. Features a 15 ohm voice coil, so it’s very easy to drive. Comes standard with Magnesium rings and gold hardware, and is significantly lighter than the LCD-4. If you loved the sound of the LCD-4 but didn‘t have the amp to drive them, you can now get the LCD-4z and your problems are solved.