Properly testing earbuds – and indeed any headphones is difficult, as some of the qualities being tested are subjective, and others depend on the structure of the user’s ear – especially with regards to IEM fitting, but also how a user perceives frequencies. For example, many people find they prefer bass-heavy earphones of some sort or another, though this is actually a bad thing – most music is mixed using very ‘flat’ speakers, which don’t emphasize any component of the music over the rest of it. This is what is referred to as a “natural” reproduction, and should be the goal of any self-respecting audio geek. (If it turns out you prefer more thump than you get with flat reproductions, there’s always the equalizer) Fortunately, good sound is no longer solely the purview of five-digit recording studios. As we examine the C5 to see if Bowers & Wilkins have managed to achieve good sound at bargain prices, there are a few things to keep in mind. First off is the phenomenon of burn-in – most expensive headphones are not shipped in an optimal configuration. Instead, they are shipped in a state that the first ten to fifty hours’ use will cause them to settle down into this optimal condition, where they will stay for the majority of their lifespan. Most cheap headphones, by contrast, are shipped in their optimal condition, and instead of burning in tend to shake themselves loose distressingly quickly. Most users choose one of two strategies related to burn-in – simply use the ‘phones out of the box and enjoy listening to the sound quality improving as they use them, or play a loop of pink noise overnight at slightly above normal listening volume. (but only slightly!) This usually produces a generally-adequate burn in without causing any undue stress, wear, or otherwise risking damage.
The C5 is built using fairly expensive methods and materials, from tungsten speaker components to give them a center of gravity inside your ear canal, to a fairly thick aluminum body for the sake of durability, to a unique, probably sintered, vent on the back of the earbuds made from tiny fused steel beads. This also implies that these IEMs are built using an open principle design, which for a given level of cost and energy use, will be both louder and higher-fidelity. This is a fairly rare design principle in IEMs, but hardly unheard of in high end headphones in general. The results of this design choice, in addition to the previously mentioned quality and power-efficiency advantages, are first off, decreased sound isolation, and second off, the unavoidable tendency of these headphones to share your music with everyone in the room, for instead of using air’s compressibility to allow them to move air into your ear canal, they rely on the entire atmosphere to dump excess pressure or vacuum into – thus sending an out-of-phase representation of the same sounds you are listening to into the local environment. This waste sound can be attenuated somewhat, but never eliminated entirely. As expected, the C5 was indeed louder at similar drive levels than comparable ‘buds. In a surprising reversal however, the C5 effectively dampened much more waste sound than expected – whether a feature provided by the “micro porous filter” or simply the necessity of moving a lot less air than full-size open principle headphones, the C5 are not likely to annoy those around you who may not appreciate the sort of music sharing open-principle often provides. Their mechanical noise isolation is also much better than expected from a single-flange tip and open drivers; while these IEMs lack any active cancellation, they make fairly effective earplugs in a purely mechanical sense. This is generally good – you don’t need to blow out your eardrums to hear your music over environmental noise – but comes with a subtle downside – you lose some awareness of the world around you. This is par for the course for all IEMs, of course, but it still bears mentioning.
Let us now turn our attention to the result of some of these expensive design choices. One of the more interesting is a claimed frequency response range of 10 Hz to 20,000 Hz – the upper bound is about par for the course and more than adequate – either my ears or the C5 gave out somewhere between 17,000 and 18,000 Hz and began experiencing extreme volume roll-off, and I am not aware of music taking advantage of these frequencies. Still, some level of audible sound was produced as high as 22,000 Hz. This is impressive, but not unheard of. The lower bound should raise some eyebrows, however. Most “nice” consumer-grade headphones are offered with a bass floor of 20 Hz, but many of those so rated are unable to reproduce a 30 Hz note. A first-pass test was conducted with the first 15 seconds of the song “Good Luck” by Basement Jaxx, which builds to a satisfying bass thump in the vicinity in its opening. Unsurprisingly, reproduction was spot-on. Using test tones provided online from various sources, I confirmed the satisfying thump at 30 Hz, demonstrated tooth-rattling volume at 20 Hz, and eardrum-throbbing performance at the rated 10 Hz. If anything, the rating seems to be a bit conservative. Many cheap headphones are rated at the extreme ends of the spectrum detectible with equipment; the C5 seems to be rated at the lower end of the range at which it provides satisfying performance. This is a welcome change, but risks selling the C5 short.
Perhaps the best way to avoid selling a pair of headphones short is to listen to them – with the music you intend to listen to on a regular basis. The only better way to perform a listening test is to use music that is even more demanding and layered with subtlety than your usual fare, so long as you know what it is supposed to sound like; the familiarity is fairly necessary to tell the difference between a bad recording and bad headphones. In my listening tests, I stuck with some old standbys – Iron Maiden is particularly good for evaluating their performance with vocals – and some newer choices, including Daft Punk’s soundtrack to Tron Legacy and The Knife’s album, Silent Shout. These provided nuanced electronic music to feed an ear details, subtler harmonics that are sometimes washed out entirely on poor quality equipment. The Iron Maiden proved unsurprisingly operatic, with the full range of Bruce Dickinson’s voice coming through clearly. The electronic music was reproduced in breathtaking subtlety and detail – all without ever touching the equalizer settings. After the startling success with both artists’ music – it sounded really good – I skipped around, looking for some kind of music that really wasn’t favored by the C5s. From classical to country all the way up to progressive rock and hip-hop, it was impossible to make them slip – though that said, many prefer modern hip-hop with the sort of thick, chewy bassline that is usually provided by massive weapons-grade subwoofers. These are not the earbuds for that sort of customer – until they turn on that equalizer I never touched. Most fans of hip-hop will find the low end thump quite satisfying, however.
One last detail must be mentioned regarding these headphones – the Apple-designed inline microphone, remote and TRRS (tip-ring-ring-sleeve) plug. It has been brought to my attention that some devices behave badly with TRRS devices; their contacts may bridge the extra conductor and cause a short circuit, or they may send one speaker’s drive current to the microphone. If one discovers their device malfunctions in this fashion when connected to the C5 earbuds, adapters to make these headphones play nicely can be had cheaply – or you could pull out that (slightly bulky) right-angle adapter thoughtfully included by B&W and use it – it will strip out the extra conductor to make these excellent IEMs work on problematic devices. The other consideration is the microphone/remote pod itself – the microphone sounds at least as good or better than others, and is adequate for its task. The remote pod, however, is unfortunately cylindrical. There’s a slight flattening of one side in the middle, play-pause position, but this is generally inadequate to keep me from squeezing sideways to no effect. Spending several seconds to immobilize the remote and then locate the proper orientation will work, but it’s not as easy to do by touch as it should be – as the single biggest flaw in this product, I can’t really call this a show-stopping bug, but I hope that the next revision will provide two indented sides, and more deeply too. This would make it easy to find the proper orientation by touch, and make the remote much more useful. The third point relevant to this feature is that this is built for the iPhone, and will probably work poorly, partially, or not at all on an Android phone, for the pinout is different and they offer no support for the volume buttons. Makible 0002 will provide a partial solution to Android users, giving them full access to the speakers and microphones of an iPhone headset, but relocating the button to the bottom of the cord on the adapter.