I let the headphones run overnight to burn them in - always a good idea if you are listening to headphones for the first time by the way. Most manufacturers should have an estimated burn in or break in time recommendation for their product. The first song for these cans is off the new Foo Fighters album Medicine at Midnight. I couldn't have asked for a better track to christen these headphones. The opening track of the album "Making A Fire" is pure fire. The Foo Fighters are known for their wall of sound and in-your-face vocals, and Making a Fire is no different. The new album itself is more fun than previous albums in my opinion, but Dave Grohl is always experimenting and working with new arrangements in his music. This track is particularly backing-vocal-heavy, which I would say is sometimes problematic with guitars, as there are usually a lot of competing frequencies. However, the chorus vocals really show off the soundstage of the HE-R10D. They are surprisingly spacious. Drums are incredibly punchy and tight. The song starts off with the drum pattern, and you can tell that the snare has tremendous weight from the get-go. It might be some of the cleanest and fattest drums I've heard on a rock album. Grohl likes to record analog too, and it sounds like a lot of the dynamics were retained for the HD digital transfer, especially as the technology gets better every day. A perfect song to set the tone for how impressive the HIFIMAN HE-R10D's are.
The next in the queue was Yo-Yo Ma's rendition of Bach's Cello Suites. I always prefer Pablo Casals' interpretation from his 1939 recordings as the gold standard, but Yo-Yo Ma's recordings have a better depth and resolution to the instrumentation to really define how well the headphone performs. I like using these recordings because of the minimalist approach in hearing the various dynamics and variations of the single voice of the cello. Some of the arrangements themselves are far from minimalist, as they are incredibly difficult to perform for a soloist, requiring a masterful dexterity and fluidity. The engineering of the HE-R10D allows the recordings to sound much larger than they actually are. The design of the ear cups allows the internal sound to have a much more expansive soundstage than a closed-back dynamic driver would normally be capable of, and I think that it's what is most impressive about these headphones to me. The reverb on the cello sounds more expressive in that it becomes easier to hear the concert hall itself in the performance. It's like the HE-R10D wants to be an open back headphone but retains the warmth and punchiness of the closed-back-dynamic-driver aspect.
The design of the ear cup allows the extra space of the dynamic driver to breathe a little more than a traditional closed-back headphone, and it does sound expressive. However, I wouldn't say it comes close to mimicking an open-back headphone either. Another note to make is that I also noticed some pretty substantial bleed through the ear cups, sounding at times as though I was listening to an open-back headphone at high volumes. Something to keep in mind if you are planning to use these headphones around others.
