Sennheiser is a German company that was established immediately after the Second World War to make microphones. Headphones followed, but the company's main headphone fame came in the late 1960s, when it introduced an "open" design. That is, headphones in which the back of the sound reproducer was open to the air, rather than being contained inside a sealed box.
The PX 360 headphones are from a different lineage, though. They use a closed design, but they also prominently feature that stylised "S"' logo, so those in the know will realise that you're wearing quality.
The headphones fold up for carrying around, but in a different way. The earpieces swivel, so that they can form a flattish bundle. They also tilt in a little, but not very much. The supplied pouch is a substantial 195x145mm, and is 60mm thick.
Finished in black plastic with silvery highlights, the ear pieces look compact, but in fact, they are large enough to encompass my ears, so that the soft pads rest against my head. That, and the reasonably gentle grip, made them very comfortable for long-term listening. The padding on the headband is quite thick, so they were gentle on the crown of the head, as well. At 169 grams, they are fairly light, too, and remained securely in place on my head, regardless of activity.
The signal cable is fixed and attached to the right ear piece. It is terminated with a right-angled 3.5mm plug of the kind that tends to work better with portable music players. Supplied with the headphones is a gold-plated 3.5mm to 6.5mm adaptor, allowing you to readily use these headphones with a high fidelity system.
What you don't get is the iPod/iPhone/iPad inline remote control, which won't trouble you in the slightest if you use some other brand of music player. But after using a bunch of headphones with this control, I found that having to scramble in my pocket for the iPod Touch in order to pause a song ended up being a significant drawback.
First, a word on loudness.
If you are determined to destroy your hearing, then these are probably not the headphones to apply to the task. They are relatively insensitive. Sennheiser uses a different method of specifying sensitivity to most brands. Its 110dB at 1 volt RMS converts (for headphones with a nominal impedance of 32 ohms) to a relatively modest 95dB for 1 milliwatt of input. Since a typical iPod Touch, iPhone or iPod Nano delivers about 1 volt max, then 110dB is pretty much the top volume you can expect on your portable travels. Most other portable-focused headphones tend to offer 6, 9 or more decibels.
Having said that, with music that is encoded at a level to come close to the full scale of what is available in a digital audio file, these headphones proved plenty loud enough for some pretty heavy rocking.
The only time you might have trouble is when transferring from older CDs, where sometimes, the music wasn't encoded very loudly within the digital space. Your iPod just simply might not turn up high enough to get a really full-throated sound out of these headphones.
However, the general performance was very solid, with extended and well balanced bass. On instruments, the mid frequencies and highs were sweet and detailed. They sounded particularly nice with acoustic strings in classical music. Yes, classical music isn't normal, walking-around fodder, but it is nice to have that performance anyway. They did add a touch of sizzle to Nick Cave's voice on Dig, Lazarus, Dig!!!, especially when turned up loud, to the point where there was noticeable sibilance.
Drums had plenty of bite, too, but seemed a touch restrained dynamically, rather than rising above the mix. Rap was excellent on these headphones. Their higher frequencies made the vocals very easy to understand, while the background musical themes and the bass rhythm was strong without being overpowering.
The bass was also strong, with Les Claypool's bass clearly articulated on Primus' "Southbound Pachyderms", and while the drums may have lost a slight edge in dynamism, they still remained very controlled.
It's a pity about the lack of an inline control because, otherwise, the Sennheiser PX 360 headphones are excellent performers.