I’ve owned the Sennheiser HD 650 for about seven years now. It’s been my primary headphones for the various equipment I’ve used. They are an excellent pair of headphones that have been scaling with my gear and doing it in ways that exceed my expectations.

I purchased the Audeze LCD 2 rev. 2 in 2019 to add to my headphone collection after researching Mid-Fi headphones. I’ve wanted a pair after encountering reviews about its bass quality similarities to the HD 650, and finally decided that I’d purchase one to compare with my Sennheiser HD 650.

After carefully listening and comparing the two, I believe they are different headphones altogether. There’s some expectation that the LCD 2 rev. 2, being the more expensive headphone would be the better-sounding headphone; however, that’s not exactly the case.

At first, I wasn’t smitten with the LCD 2 rev. 2, I thought it was quite flat compared with the HD 650s. They didn’t provide the warmth and forwardness that engaged me as with Sennheiser HD 650s. The Sennheiser HD 650 provided a more life-like timbre that appealed to me. Because the notes are lusher, the HD 650 captures a fuller expression of music.

With the LCD 2 rev. 2, the presentation is more balanced and spread out in its big and well-defined soundstage. The Sennheiser HD 650 soundstage doesn't reach this level of nuance, which may be desired by some.

With time, I've come to appreciate the more balanced presentation along with the bass quality of the LCD 2.2 Pre-Fazor, but without proper cabling, I find that I prefer the expressiveness of the Sennheiser HD650.

With the Sennheiser HD650s, raw detail is captured through the forwardness of the notes to a remarkable degree. I'm constantly left surprised and satisfied at how well the Sennheiser HD 650s scale with equipment; with the Feliks Audio Euforia, the G1217 Sunrise III, ampsandsound Kenzie OG Rev. 2, and ampsandsound Agartha, the changes in the sound signature have always been enjoyable to experience (although I'm finding over time that much of the gear I use scale with more powerful gear).

Presentations are entirely different with between the Sennheiser HD 650s and LCD 2 rev. 2. I find that the HD 650 is not confined to a soundstage, has a more life-like timbre, and is forward. The Sennheiser HD650 is an enjoyable headphone for any person as a generalist headphone. With the LCD 2 rev. 2, I found that a premium cable allows me to enjoy the headphones more. The Audeze LCD 2 rev. 2 sound better with the Audeze Premium cables, bringing more clarity, sparkliness, timbre, a new sense of space, improved imaging, and definition.

When I started out becoming interested in Hi-Fi, the Sennheiser HD 650s were always a headphone that I saw talked about on Headfi.org. After seeing it scale well with the gear that I own, it has become one of my favorite headphones. The soundstage on the Sennheiser HD 650, however, is not as wide, and the presentation is quite confined in that regard. 
 
Both headphones are worth owning, but with proper sources and cabling, you can give more life to the Audeze LCD 2 rev. 2. I haven't had the opportunity to buy quality cables for my Sennheiser HD650, but judging from what I've heard and read, this may not be necessary

Sources: Audio-GD HE-7 MK I, Yulong D18

Cables: Blue Jeans Coaxial Cables (3 foot, 6 foot)

USB: Matrix Audio X-SPDIF 2, Singxer SU-6

Amplifiers: Yulong A18, Feliks Audio Euforia, ampsandsound Kenzie OG Rev 2, ampsandsound Agartha 2021

Product Links:

Sennheiser HD-650: https://amzn.to/3oy3vRn

Audeze LCD-2 2021: https://amzn.to/2YcysQl