Micro-porous filters: The C5 is an open-back earphone, but one whose earpiece housings are significantly different from competing designs that often provide tiny pencil-point-sized vents or ports. The C5 earpieces feature relatively big rear openings, where the “port” is nearly as large in diameter as the barrel of the earpiece housing itself, and where the port opening is fitted with a special “micro-porous filter”. At first glance, the filter appears to be made of a foam material, but that turn out to be made—check this out—from “hundreds of microscopic steel balls” (the tiny metal spheres are just barely visible to the naked eye).
As a general rule, open-back designs are though to offer superior sonic openness, transparency, thus enabling the earphone to “breathe” with the music. B&W makes similar claims for its open-back design, but goes even further, stating that its distinctive filter “acts as a sonic diffuser, opening up the sound and making music feel remarkably rich and expansive.” What B&W doesn’t say, though I suspect that it is true, is that the filter not only acts as a diffuser, but also adds a just-right amount of acoustic loading that helps control back waves from the earphone driver.
Noise-isolation design: Like most earphone makers, B&W claims that the C5 offers good noise isolation, but also makes this surprising claim: “…these in-ear headphones let in just enough ambient noise to allow you to retain your sense of place” (italics are mine). It appears, then, that B&W is trying for a best-of-two-worlds design, where the C5 provides quiet backgrounds, yet invites listeners to maintain at least some measure of “situational awareness”—a balancing act that’s tricky to pull off.
• Four sizes of rubber ear tips. Note that each ear tip appears to feature two different compositions of rubber, with a relatively firm inner sleeve made of black rubber, and a dome-shaped outer made of a softer, translucent gray rubber-like material.
• A carrying pouch made of a suede-like synthetic material. The interior of the pouch provides a somewhat inscrutably designed headphone holder that is also meant to serve as a winding spool for the signal cables. (Hint: Read the online manual and look at the provided illustration to see how to fit the C5’s onto the headphone holder for best results.).
• The C5 signal cable features and inline three-button “Made for iPhone” remote control/microphone module.
I personally found the C5’s extremely easy to use and very comfortable to wear—even for long listening sessions. But with that said, a few tips are in order.
Getting the most out of the C5’s Secure Loop system: When used properly, the C5’s secure loop system works beautifully and feels great. But the key to optimal performance is to start out with the secure loop set to a small size and then to slowly expand the loop until it fits comfortably against the folds of your ear. Remember: when the C5 is properly fitted, the secure loops—and not the rubber ear tips—are what holds the earpieces in place.
Hint: The “Features” page of the C5 section of the B&W website features an animated presentation that will show you how to fit and adjust the secure loop.
Use right-size ear tips—not oversize ear tips: With the C5 as with any earphone, it pays to try different sizes of ear tips to see what works best. But bear in mind that with the C5—unlike many of its competitors—you don’t need to resort to using oversize ear tips to hold the ‘phones in place. Take advantage of this fact and be sure to experiment with smaller tips than you might normally use, just to see what actually sounds best.
Hint: I found oversize ear tips tended to make the C5 sound overly bass-heavy, so exercise patience and choose ear tips carefully for best results.
Manual: By far the best manual for the C5 is the one found online at this link. Note that the PDF manual at the B&W site is different from and better than the printed manual that ships with these earphones.
Caveats: While I had no usability complaints with the C5 at all, I am aware that some reviewers have expressed concerns in the following areas.