Wearing Style: Headband Ear coupling: Circumaural Transducer principle: Dynamic, closed Frequency Response: 10-42,000 Hz Impedance: 23Ω Sound Pressure Level: 114dB (1 kHz / 1Vrm) Total harmonic distortion: <0.08% (1kHz, 100dB) Bass Boost: +/- 5dB at 50 Hz Contact pressure: 5.5 ~ 6.8N Weight (headphones excluding cable): 400g Accessories include carry bag and 3.5mm to 6.3mm adapter.

* I'm using a G.R.A.S. 45CA head (affectionately referred to in the industry as Thor's Hammer, due to its shape), which is equipped with G.R.A.S. IEC 60318-4 ear simulators with G.R.A.S. 40AG calibrated microphones (using G.R.A.S. 26AS microphone preamplifiers). This is all plugged into a G.R.A.S. 12AQ microphone power module. I'm currently evaluating measurement software and/or hardware for the final setup, to use with the G.R.A.S. gear. In the interim, the output of the 12AQ is being fed to a CEntrance MicPort Pro (which is a 24/96-capable USB mic pre) for analog-to-digital conversion. The MicPort Pro is plugged into my iMac, where I'm using TrueRTA for real-time analysis (in Windows), and FuzzMeasure Version 4 Beta (in Mac).

At Munich High End this week, one of the most notable launches--at least in the Head-Fi world--will be Sennheiser's (now-leaked) Sennheiser HD 630VB. The cat's out of the bag, so let's start with some photos (click on them to see larger size):The last time Sennheiser released a new headphone with the "HD" designation--with a number in the 600's behind it--it was the Sennheiser HD 650, nearly 12 years ago (in 2003). Whereas the HD 650 was rather a lot like the HD 600 (and the HD 580 before that), you can see in the photos that the new HD 630VB has no outward familial ties to anything I can think of from Sennheiser before it.In terms of its design, the HD630VB definitely marches to the beat of its own drummer. Like Sennheiser's HD 25-1 II, the HD 630VB has rather atypical right-side cable entry. The HD 630VB's ear cups, yokes, and sliders are made of aluminum. The right ear cup's flat surface is dominated by a dark circle that houses the volume and music/call control buttons (which I'll get to shortly). The left ear cup, however, has no controls, and Sennheiser did not elect to put a decorative dark circle in its center to match the right cup--they left its beveled silver-colored aluminum to dominate that left side, sans any logos or emblems. The contrast between the two cups is certainly unique.The HD 630VB is a large headphone, with full-size ear cups that are rather thick. Fortunately, the HD630VB has a couple of tricks up its sleeve that most closed headphones this large do not have: first, the earpieces rotate to fold flat; and, also, the headband has sturdy-feeling hinges—with very nice, very positive detents—that allow the HD 630VB to fold flat, and to stack the flat-rotated ear cups one on top of the other. While it's not ultra-compact no matter how you fold it up, the HD 630VB's flat-folding design and hinged headband make it far more stowable than most headphones of similar size.Let's look at the HD 630VB specs from Sennheiser:Yes, you read that right: "Bass Boost." The "VB" in this headphone's name stands for "Variable Bass." This, and perhaps a few other things, are likely to give some audiophile's pause. What other things? The Sennheiser HD630VB's headphone cable is captive (non-removable), and has an inline microphone for headset use. The controls on the right ear cup include music/call controls, and an iOS / Android switch to optimize its control compatibility with most popular mobile phones. To further optimize the HD 630VB's drivability from most mobile devices, it was designed with low nominal impedance (23Ω) and high sensitivity (114dB).While some of the above features/specs are not typical of the audiophile headphones we usually discuss on Head-Fi, docross the HD630VB off your list of candidate headphones if you're looking for a headphone with impressive sound that's both full-size and closed-back. With an expected retail price of 499€--and $549.95 (USD)--the Sennheiser HD 630VB is priced to compete with the likes of the Fostex TH600, and, to my ears, it's in league with the big, black Fostex. I actually think many will find the new Sennheiser more versatile with its well-implemented passive bass control (which I'll get to in a minute), not to mention being better suited to be packed up and toted along. Also, unlike the semi-closed Fostex TH-600, the Sennheiser HD 630VB is a fully closed design, meaning it's better at keeping the music from leaking out, and has solid passive isolation.As for its sound, the HD 630VB is very versatile, helped by the fact that its bass control (rated by Sennheiser for +/- 5dB at 50Hz) is, to my ears, very well implemented. It actually has a more pronounced effect the further down you go below 50Hz, but little effect in the direction of the midband (until you really crank it up).The bass control dial is continuously adjustable, but marked by several index points, starting with MIN, and then five primary marks between, before hitting MAX (for a total of seven major index points, each sub-divided into quarters). No matter how you set the bass control, the HD 630VB has some upper-bass emphasis, but I find it very well voiced there, and not at all intrusive. Between the MIN and the first major index point, I can discern little change in tonal balance. However, when I keep turning past there, the changes become more evident. What I love is that there's minimal effect on the lower midrange, until you get into its highest settings, at which point the lower mids do thicken noticeably--fortunately, the onset of this happens somewhat quick, and so it's rather easy to avoid.For the last several months, I've been in the process of putting together a measurement system (which I'll discuss in much greater detail separately), and decided to use what I have on hand so far to measure the HD 630VB in its various bass settings (especially since the only other such measurement I've seen of it so far looked to me to be compensated). Here's the raw measurements (no compensation at all) from my measurement system in its infant form(click to see larger size):So far, most of those I've let listen to the HD630VB have been impressed with the implementation of its passive bass adjustment implementation, and it's easy to see why.In terms of how I set the HD 630VB's bass adjustment, I've found myself using the third notch above MIN (the red line in the graph above), and the fourth notch (the purple line), and moving in between those. Fortastes, I've found this range the most even-handed with the HD 630VB, while still giving me some extra oomph down low for a little heightened drive. @joe tends to prefer a thicker sound than me, and he's been using it at around the second from highest setting (the one just below MAX), and sometimes backs off a little bit from there.While I don't often go beyond the fourth notch--andrarely venture anywhere near MAX--I do find the latitude to thicken the sound at or near the HD630VB's highest bass settings a blessing for some of my ultra-tinny 80's pop and new wave music. It can also add a sense of welcome tonal depth to some of my thinner, reedier old jazz and cabaret recordings, by the likes of Django Reinhardt and Edith Piaf, for example.I think one of the HD630VB's strongest points is its imaging, especially for a closed headphone. I know a lot of tuning went into this aspect of the headphone, and it's with great effect--never reaching out like the-open flagship Sennheiser HD 800, but often casting well beyond what I'd expect of a headphone that is as closed as the HD630VB is. Speaking of the HD 800, here's a frequency response comparison between the HD 630VB (set to the third notch above MIN) and the HD 800 (click to see larger size):I think one headphone a lot of shoppers will inevitably compare the HD 630VB to is the Fostex TH-600, given that they're both closed (well, the Fostex is-closed), and that their prices are within striking distance of each other (the Fostex's street price is currently around $50 higher). Again, I think the HD 630VB is a worthy contender for the venerable Fostex, and I'd compare them thusly: The Fostex--perhaps owing to its semi-open design--has tonal characteristics to me that are, in some ways, rather less like a closed headphone (than, say, the Shure SRH1540, or this HD 630VB), being a bit more even-handed from bass to mids, with more open-sounding, more soaring treble, too.If the TH600 is closed enough for you and your environment, and you don't desire greater versatility from it, I'd say you might end up preferring the TH-600 to the HD 630VB. If, however, you've found the TH-600 too open (in terms of leakage in or out), and/or you've found the TH-600's treble a bit too tipped-up for your tastes, then the Sennheiser HD630VB is a must-audition headphone.Here's a couple of frequency response plots showing the Sennheiser HD 630VB and the TH600 together, the top one with the HD 630VB set to bass level 3 (three above MIN), and the bottom one showing the HD630VB set to bass level 5 (click to see larger versions):Is the Sennheiser HD630VB capable of being adjusted (via its bass adjustment knob) to the type of neutral presentation of something like a Focal Spirit Professional? No. However, if you've found the Focal Spirit Professional a bit lean or cold for your tastes, then the spunkier Sennheiser HD 630VB might be more to your liking.What quibbles do I have with the HD 630VB? Though it has a certain charm about its appearance, it is a very noticeable headphone on the head. While this doesn't bother me (I've been known to wear the Fostex TH-600 and Audeze LCD-XC out and about on rare occasion), some might find it a bitobvious, in all its large silver glory. As for sound, I've found its adjustability suits its purpose for me for on-the-go use. When I've used it at my desk, though, I've had occasion to wish for a little more richness in the mids (low-mids to mid-mids), but not to any degree greater than other minor wishes I have for just about every headphone I use.Don't let the bass adjustment dial, inline microphone, or song/call controls fool you into thinking the Sennheiser HD 630VB isn't a serious closed headphone at the price, as it very much is. As with any other headphone, it won't be totaste, but its versatility may broaden its appeal. If you're currently shopping for a good closed headphone in the ~$500 price range, make sure to put the Sennheiser HD630VB on your list of candidates to audition. In my opinion, it's a serious closed headphone candidate at the price, that just happens to have some unusual (but helpful) features thrown in.