As the first truly new high-end dynamic-driver headphones to hit the market in quite a few years, when Sennheiser’s HD800 was introduced at CES on the 8th of January 2009, they caused a massive storm. Since the last truly high-end pair of dynamic driver headphones at this level had been, arguably, Sony’s R10s (the Qualia 010 is another matter altogether) and the only equally expensive headphones available at the time were Ultrasone’s Edition 9s, it became something of a re-awakening of the high-end headphone market, which subsequently exploded with Audeze and HiFiMan’s planar headphones.
Not only is the design technically fantastic, but the large cups and light-weight design makes them highly pleasant to listen with, even for long periods of time (issues with the frequency response not withstanding). They copped some flak for the plastic used, even if it was intended to minimise vibration, and distortion. The head pad and ear pads are not the most robust and may require replacement after some years, which is thankfully not that costly, unlike the cable!
Seven years on and the only thing that had been added or changed with the HD800 was the introduction of an optional balanced cable to go along with Sennheiser’s headphone amplifiers, the headphones themselves still highly competitive with everything out there, though arguably with careful amplifier and cable considerations, or possibly damping mods, depending who you ask.
So it was at the 2016 Spring Fujiya Avic festival that was I heading into the building with Jude, who told me he had to drop something off to Axel Krell of Sennheiser. That “something” was a pair of HD800 S, prompting me to ask for a quick video.
It wasn’t until recently that I actually had a chance to sit down and have a proper listen with a pair, and only thanks to Anakchan offering to lend me his pair.
The HD800 itself is quite unique in the world of headphones, including for Sennheiser. When an image was leaked, pre-announcement, nobody believed it, as the design looked more like something Sony would make. This makes the most sense if you’ve seen the Qualia 010.
As it is, they are still the only pair of headphones to use a ring radiator driver, which is shaped like a donut on one side, rather than a disk, with a hole in the centre. That hole has been the centre of attention, pun very much intended, as it holds the secret to the difference between the HD800 and HD800 S.
Before explaining more, it is worth re-visiting the original model and some of the good and arguably less good aspects of its design.
The HD800 uses a ring radiator driver — basically a shape that looks like one side of a donut with a hole in the middle. Being a fairly large diaphragm and the cups being large, the result is quite a large presentation of the music. Despite this, there is sufficient bass, though something of a drop-off towards the deep bass.
Dynamic drivers typically have a drop-off in the deep bass to avoid distortion which increases rapidly at very low frequencies. This is, to a degree, why planar magnetic headphones have become popular, as they can avoid this. Regardless, the HD800 did better than average.
The mid-range is somewhat recessed, increasing the sense of space. However the treble is where things were somewhat unusual. Most headphones have a peak in the treble between 8-10 kHz, giving instruments, which usually top out much earlier, a sense of “air”. Without this peak the music can sound muffled, such as with V-MODA’s LP series which was designed without the peak for listening loudly to club music.
The HD800 has a peak at 6.3 kHz, lower than most, and making them sound brighter than average. This became problematic with some music as, say, the Cowboy Junkies famous song Sweet Jane, becomes SCHWEEEEEEEET Jane, which is unpleasant to listen to.
This lead to people often pairing the HD800 with warmer-sounding tube amps, as well as re-cabling them to try and tame the peak. Eventually people such as Jazz Casual began sticking things inside the cups to see if the sound signature could be improved.
Inside the cups, under the fancy two-layer dust cover there are plenty of surfaces which can reflect sound and potentially introduce harshness, such as the metal ring securing the driver, the metal back grill and the plastic surfaces. Covering these surfaces to varying degrees with felt, foam or perforated non-slip matting seems to improve things considerably, reducing the internal reflections. I tried this myself with non-slip matting I bought in my local hardware store.
However, not everyone likes the improvement, even if it does result in a more precise sound, and sometimes one with a bit more bass. The theory I have behind this relates quite a bit to live music, and how we listen to music in general.
I recall, many years ago, when I first heard one of my favourite bands at the time, Massive Attack, played on a high-end system instead of from a radio or other cheap stereo. The clarity was unexpected, which while good in some ways, felt odd. Likewise, when most people hear live music it is at a concert or less than ideal venue, where the sound is reflected off everything. Even a classical music concert in a properly designed hall presents most of the music with carefully tuned reflections.
In contrast, I used to sing in a boys’ choir, where our venue for practice was sometimes in the recording studio in the School of Music. That room had perf-board walls to damp sound, and we’d always enjoy the weird feeling of an over-damped room which, even upon entering, would mess with our voices. If you’ve ever been inside an anechoic chamber and had someone speak to you, it is freaky how their voice will come verydirectly from them, with no reflections at all. Most importantly, being inside these rooms feels unnatural to us, as we’re used to hearing sound reflected around us.
Similarly, some damping mods to the HD800 can have a similar effect, making the music sound too accurate. While it has been shown to improve them on a technical level, like an anechoic chamber, it can end up with something that sounds unnatural to us.
That leads us to the HD800 S. The primary physical difference is that in the hole in the middle of the driver is what appears to be a Helmholtz resonator — a device that is used to either reduce or emphasise selected frequencies. In the HD800 S, it has been shown in measurements to reduce the bothersome 6.3 kHz treble peak. Additionally, the drivers have been tuned to have more low bass, but with the consequence of more distortion. 
The HD800 S cups, showing the small donut-shaped resonator in the centre hole.
This makes them more sonically pleasing for many people, especially those who like the HD800, but find it too bright. However when I first put them on and listened, the sensation of listening to the mid-range felt very odd, and it took me a while to figure out exactly what was going on.
Listening to Macy Gray’s latest album, recorded binaurally by Chesky Records, Macy herself appears dead centre, while the instruments of the band are quite strongly either on the left or the right. With the HD800, my mental image of the sound is of Macy’s voice in the centre, tapering off sharply and then echos of her voice off the surrounding walls and objects, then the instruments sharply in focus in their respective positions.
With the HD800 S, where the image is the same, the in-between echos of the surrounds of the building seem to be less prominent, increasing the contrast of the direction her voice is coming from and the direction the instruments come as well. It is as if the sound has been damped and the natural echo of the building reduced or removed to a significant degree. I believe it was that which made me feel that the sound was unnatural at first.
However with a lot of music that sounds a bit too thin through the HD800, the S is more pleasant to listen with. Now we have a better balance between the huge spaciousness of the sound and the enjoyable warmth so many of us prefer and would compromise with via tube amps and re-cabling.
Unfortunately, even to the point when people had convinced me it was impossible, I can’t enjoy listening to either pair of headphones with the stock Sennheiser cable. I’ve been through a bunch of cables, for which I have a dedicated thread, so I wont go further than to say that, for reasons I can’t explain, even if it doesn’t change their frequency response, I find that the stock cable does something I can’t explain that makes even the HD800 S sound thin and unpleasant to me.
As for gear, the cost of getting good listening from the HD800 S is a lot cheaper than it was when the HD800 was released. A Chord Mojo or even a Schiit Vali 2 (preferably with a better tube) are a couple of my favourite which have given me much listening pleasure, even if they don’t bring out all the detail they are capable of retrieving. Likewise, ALO’s Continental V5 makes for a fantastic booster for any DAP that doesn’t quite get up the voltage swing to be ideal, such as Soundaware’s M1. On the other end of the scale, Woo Audio’s WA8 has the most syrupy delicious presentation, and my peak amp for both dynamics sounding pleasant is ALO Audio’s Studio Six. Sometime I’ll have to try them on Schiit Audio’s Ragnarok and the new Cavalli amps, if not a Chord Dave.
In the end, the HD800 S, when combined with good equipment, can be an amazingly pleasant pair of headphones to listen with. After I got over that initial period of weirdness, and started doing comparisons, I would pick it up over the HD800 to listen with, and that is where it really counts.
If you’re thinking to buy a pair, please help support my channel by buying them from this link: http://bit.ly/2pMt3J4
Thanks to Anakchan for the headphone loan, and to Kimber Cables for the cable.
