Pros: Superb sound quality. Gorgeous design. Luxurious build. Excellent isolation. Excellent comfort. No need for amp.
Cons: A tad large for a portable.
Design & build quality
When you first unbox the P7 and see it laying there folded in its tilted presentation, you instantly know you are dealing with quality of seldom seen measures. The all leather and metal built P7 smells like a brand new car when you take it out of the box and B&W have paid attention to every little detail. The design is basically a larger and slightly refined version of the P5. The quality of the leather, the precise stitching, the steel accents, the brushed aluminum nameplates with the same flawless edge-cutting you find on the newer Apple iPhones and iPads - everything just screams luxury and quality craftmanship. The hinges feel a tad fragile, but other than that build quality is unquestionably top notch. The headband seems thicker than it needs to be, but hey that's part of the design.
To put it simply, I think the P7 is one of the most beautifully constructed headphones ever. My only real complaint is that it's perhaps too fancy to carry with you outside. B&W have also confirmed for me that the leather is not coated for water and sweat resistance, so I wouldn't wear these outside in more extreme weather conditions.
I really like the cables of the P7 too. They are nicely thick (unlike the pathetic cord of the P5) don't tangle and don't feel stiff. The remote on the I-device cable is of very nice quality. Its fit and finish is as good as the rest of the P7 and the buttons are easy to press, unlike with the frustrating remote of the KEF M500.
The P7 is not a small headphone. It's not huge by any means, but it's a substantial piece for something to transport with you. Unlike the KEF M500, I can't put the P7 in my pocket. But B&W has at least done the best they can with the size and included a very well designed folding mechanism. The pouch in which you store the headphones on the go won't provide a whole lot of protection, but at least the cans are covered from dents and scratches. The pouch is also leather, closes magnetically, and has a very soft interior. Nice!
In terms of comfort, the P7 is initially a little clampy. But the pads and headband will soon soften up a little bit and the pressure loosen up enough for you to enjoy these headphones for multiple hours with no pain. They are not the most lightweight portable cans in the world, and I wish the headband was just a little bit softer, but I still find the P7 to be a very comfortable headphone. The earpads provide ample space for your ears (unless they are on the really large side) so you'll feel no discomfort on the ears after extended use.
The moderate clamp (which, by the way, makes sure the P7 sits firmly and securely on your head) of the P7 combined with the great seal of the ear cushions provide excellent passive noise isolation. With music playing decently loud, these will shut out your everyday life with no issue. For frequent airplane or subway use, in-ears or noise cancelling headphones like the Bose QC15 are probably better choices, but as far as passive noise isolating over-ears go, the P7 is up there with the best I've used.
I was never impressed by the dark and colored sound of the P5 and P3. But with the P7, Bowers & Wilkins prove that they have the skill to compete with the big players!
The P7 is the most naturally resolving portable headphone I've yet heard, while at the same time providing a tremendously musical listen.
The bass is warm, firm, very well extended and wonderfully well defined for a closed headphone. It punches with strength and weight, but does so with excellent control and finesse and a surprisingly low sense of resonance, resulting in clean and pure bass notes. As with most portable headphones, the bass has some extra potency to it - but just the right amount in my opinion. The bass blends marvelously well into the midrange, with no unwanted thickness. The bass is even better than that of the KEF M500, with an added sense of control and refinement. B&W have some special attributes with regards to the handling of airflow from the driver inside the cups, and whatever it is it seems to have worked out. Wonderful.
The midrange is equally fantastic. Voices and instruments are reproduced with beautiful clarity, acuity and no sense of hardness whatsoever. Vocals are brilliantly defined and the midrange tone of the P7 is very open sounding. I hear no strange dips or peaks in the frequency response at all. If I am to nitpick, I think the P7 is just a tad lacking in organic presence. But just a tad.
If you've previously discarded B&W headphones for their recessed treble then the P7 will come as a surprise. Expect no veil or lack of extension here, the treble of the P7 is as excellently defined and refined as the rest of the spectrum. It's lively and rich, with tremendous detail and resolution for a closed headphone. But it's never harsh. It's never shrill, thin or hard sounding. The biggest issue I have with the KEF M500 is the somewhat metallic sounding treble, and the P7 has no such issues. The treble is quite accurate, and reproduces those hard-to-get-right high frequency instruments faithfully. Like the bass, the treble is marvelously well integrated with the midrange, and the coherency of the P7 is as good as any sealed headphone I've listened to. Some will find the treble of the P7 to be a little bright, but this has not proven to be a problem in my case. The treble is in fact livelier than perfectly neutral, but it seems to always stay on the fun side, rather than crossing into strident territory.
And then there is that tremendous soundstage. The P7 images amazingly well for it's size and handicap (meaning the sealed construction). Providing the recording is up to snuff, the P7 paints the soundstage accurately, with a great sense of depth and ambience. Vocals are pushed up front and centered, instruments have proper space and excellent focus.
Now, the P7 is not a reference headphone. I have heard even tighter bass, I have heard even more transparent mids, I have heard even smoother and more refined highs and bigger and more precise soundstage abilites. But not from a portable headphone. Not from a closed-back headphone at this price. And, to my memory, I've not heard another closed-back headphone at any price which does so beautifully in every area and provides such a coherent and natural sound as the P7. At least not at the time of this review.
How much better can portable headphones get? I mean come on! I know it's a dangerous thing to say, but I think it's gonna take a while until a company releases a new contender that's as uncompromising as this. The P7 looks fantastic, it feels fantastic, it's very comfortable and isolates very well, and it SOUNDS just beautiful. If you seek a high fidelity headphone, value both form and function and have $400 to spend on a portable, I can't think of anything I'd recommend more.