O.K.... my HD58X is 5.4dB louder than the HD650 which brings the sensitivity to 110dB/V for the HD58X (102dB/mW) versus 100dB/mW for the HD650. There are certainly better headphones that resolve more (at higher or much higher prices), but these are good especially considering the aggressive price. It's a headphone that sounds good (not excellent), and suits general use with music, gaming, watching youtube.

It may not tonally superior to an original HD600, and it’s certainly not tuned as well as a 560S, but none of that really matters much as it could be more enticing to a newbie audiophile (plus, it sounds great and that’s really all that matters at the end of the day). In other words, One difference you’ll notice here vs. others in the line is the bass; there’s more of it for sure, but it’s still not over the top. But make no mistake, a wonky tuning cannot and must not be handwaved off as being simply unique. The HD8XX is, in terms of tonal balance, definitely up there in terms of Sennheiser’s strangest. If we were to use the HD6X0 as the reference for “correctness” (not saying that it is, just as an example due to the HD6XX being the prime comparison point in this situation), you can see how a 10dB(!) recession at 2kHz can be a… cause for concern. Once there, the sound was delightful with surprisingly good amount of spatial qualities (I give it B+). I listened for the rest of the evening after I tested and did not want to put it down.In fact, these are ranked rather highly on my most comfortable headphones of all-time list, and I’ve always likened them to receiving a warm hug from an old friend. For whatever reason, I found the image here significantly wider than that of an HD600, especially in playing Fallout 4.

Going to return them to get a hd58x since I like the design more and will probably prefer the larger cups.

HD58X Specifications

If I could use an analogy, the sound of the 58X is like a photograph that has just a hair too much contrast.