as reviewed by Danny Kaey

I have been playing around with my iPod for the past year or so. Since most audiophiles live in the dark when it comes to such gadgets, let me inform you that some 22 million iPods have been sold to date, and there's no end in sight! The iPod was nothing more than a curiosity back in 2002, but it has since revolutionized the entire market for portable music players. Coupled with the stupid-simple interface of iTunes and the even simpler interface of the iPod itself, it is no wonder that Apple has the lead. No other player or online music service provider even comes close. If you think that Sony's Walkman was popular, think again. Yes, Sony does have a handful of portable hard-drive and flash-based players, but none are even blips on the radar screen. So dire is the situation at Sony that we may even see some form of collaboration between the two giant companies. At the last MacWorld Expo, Sony's president stood side by side with Steve Jobs, mumbling something along those lines.

Of particular interest to audiophiles is the fact that the iPod is capable of some pretty good music playback if the signal is encoded in either Apple's own lossless codec or the more universal AIFF format. On my iPod mini, which holds 4 Gigabytes of data, I have a good mix of mp3/AAC files encoded at 128 kps and lossless/AIFF files for serious listening sessions. The iPod has never yet failed me, and better still, I can install it in my car! About the only thing missing from a full experience is the fact that Apple (along with virtually everyone else) ships the iPod with the lousiest of headphones. You really don't know what you are missing unless you hear otherwise. They had to save money somewhere, but at least it is a problem easily solved by swapping the stock headphones for more audiophile-approved ones. The problem is, with so many aftermarket headphones on the market, where does one begin?

I looked around and came to several decisions. I could use standard large headphones—AKGs, Sennheisers, etc.—but would lose the advantage of mobility. Also, with the amount of air travel I have been doing lately, I wanted to find noise-canceling headphones of audiophile quality. Finally, comfort was a major issue with most earplug-style headphones. If I have to keep headphones plugged into my ears for extended periods of time, they had better be comfortable! After browsing the various websites, I came across Sensaphonics, a company based in Chicago, Illinois. Sensaphonics is different from most other headphone manufacturers, since they are first and foremost about hearing protection and high-quality audio reproduction. The company was founded by audiologists, and I immediately noticed the no-frills professional approach on their website (www.sensaphonics.com). From top musicians to studio engineers to racecar drivers, Sensaphonics has carved out a nice niche in a market that truly relies on high-quality in-ear headphones, or as they call them, in-ear monitors.

The only thing left to do was to find out what the fuss was all about, so I got in touch with Julie Glick, Sensaphonics' marketing and PR manager, to request a review pair. Boy, was I in for a surprise! First, to achieve the appropriate level of sound insulation and hearing protection, Sensaphonics builds the ProPhonic 2Xs around impressions taken from your ears, for a perfect in-ear fit. Second, the engineers at Sensaphonics tackled the issue of sound quality by installing two drive units (!) and a crossover (!!) in the custom-molded monitors, thereby offering truly state-of-the-art headphone playback while canceling ambient noise by 26dB. Third, since each product is custom made, you get to choose the color of the mold. In my case, it had to match the bright white iPod color popularized over the past few years. Wow! Of course, this superlative level of expertise and performance comes at a price, which in the case of the ProPhonic 2Xs is $750 plus the cost of getting custom ear molds made up by your local audiologist. Fortunately, Julie has a list of approved hearing specialists in your area, so getting the mold made didn't take too long.

Having impressions made of your inner ear is a very strange, though completely painless experience. First, the audiologist looked inside my ears to make sure that the presence of earwax would not cause imperfect impressions. The next step was to insert a bite guard in my mouth, as the impressions are best taken with the mouth and jaw open. Lastly, he injected some special foam into my ears that hardened to create the impressions. It was a bit weird having a complete stranger plug my ears with goo, although I knew that the monitors will only perform as well as the impressions that he make. Minutes later, I left the office with a little box containing my ear impressions. A few weeks later, Julie phoned me up to let me know that the monitors were on their way. Anxiously awaiting their arrival, I loaded up my iPod with nothing but the best uncompressed music material I could find in my collection.

The little package arrived, and my first impressions (so to speak) were superbly positive. The monitors are packaged in a nice, watertight, mini flight case, complete with a cleaning tool, a ¼-inch plug adapter, a brief instruction manual, and a pouch that contains the monitors. Except for my Brinkmann LaGrange, I can't think of another time that I was this impressed by unpacking a product. Weighing almost nothing (actually, one ounce!), the build quality is absolutely incredible. The cord for each monitor is of great elasticity and light weight. Finally, a beautifully made braided cable ends in a gold-plated mini plug. The ProPhonic 2Xs looked like a million bucks, putting their $750 price tag in proper perspective.

Finally, it was time to hear them perform. Due to their custom-molded nature, you can't just insert them into your ears. A unique procedure is required. Each monitor must be twisted clockwise about half a turn, then inserted and untwisted inside your ear. The procedure takes a few tries before it is perfected, but now, three months later, it takes me no more time than it does to insert normal earplugs. I immediately noticed the complete absence of outside noise, which was an experience in itself. It is not so much the fact that you enjoy near silence, but rather, you realize just how much noise we have around us at any time of the day and night. You have to get used to the feeling before you really appreciate it.

Finally, the moment of truth came—plugging the monitors into my iPod and pressing Play. I wasn't sure what to expect, as listening to headphones is very different from listening to loudspeakers. Everything happens in your head, with immediacy and a very forward presentation. Yello's "Time Space" was the first track I chose. It took all of ten seconds to realize that the ProPhonic 2Xs were nothing like any other headphones I had heard, save my AKG K1000s. From the darkest and most quiet backgrounds I have ever heard (a 26dB cut in ambient noise will do wonders for your critical listening), Yello's sonic masterpiece emerged in a way I had truly never experienced. It was as though I was standing outside my brain looking in. Synth and various processing effects were painted with such accuracy and delicacy that they gave the words "spatial cues" new meaning. Such extraordinary clarity, focus, and precision is normal with my AKG K1000s and Marten Design Dukes, but not your average headphones or loudspeakers.

Clearly, the ProPhonic 2Xs are not your average headphones. Captivated by the emergence of music from the quietest of backgrounds, nothing prepared me for what came next. In my book, bass is an underrated yet utterly fundamental element of music. It is underrated because it is difficult to reproduce correctly, and fundamental because bass is what gives the sense of acoustic proportion that allows you to perceive the correct size of instruments and the space they occupy. Every time I play "Time Space" on my big system—the Marten Design Dukes augmented by the awesome Velodyne DD-15—I revel in the sonic aura that envelops me. Bass has such natural force and impact that I can't help but tap my feet to the beat. (Cranking it louder is even more fun, but that is usually accompanied by a phone call from the neighbors downstairs, asking if I had just felt the earthquake—this is LA, after all!)

Bass reproduction through headphones is a hurdle. Since there is nothing for the bass waves to resonate, they have much less impact. The only headphones I have come across that are able to provide powerful bass are the K1000s, though they are not really typical headphones. With the K1000s, I can feel the bass much like I can with the big system. Other in-ear headphones I have tried have never managed to do that. They hint at the presence of bass, but you don't know for sure. With the 2Xs—shazaam! This can't be! Did I leave the same track playing in perfect sync on the big system while listening to the Sensaphonics? No. These are simply the first in-ear monitors that have true bass impact. Bass emerged from total silence, extremely well defined and super quick. This was almost perfect bass. I'm not sure of the technical explanation, but I truly felt the impact of each bass note. I moved on to some other bass-heavy tracks, and each time, the result was identical. I could feel bass all around me. It was astonishing, to say the least.

The sound of these in-ear monitors is on the neutral side. They sound somewhat less hi-fi when playing less than full-resolution music. Even with the smallish hard drive on my iPod mini, that still allows for plenty of musical enjoyment at full resolution. The fact that you have these monitors planted in your ears means that you can enjoy complete silence, even on an airplane. I have always despised listening to music or watching films on a plane, as the jet engine noise masks the sound. I felt it best to not listen to anything rather than subject myself to future hearing problems. I always wonder if my fellow passengers are aware of the danger of playing music too loud over headphones. Now, let me tell you, Stravinsky's Firebird never sounded so good on a 777!

Some people will feel hesitant about inserting things in their ears, much less things that look like they came off the set of a Star Trek episode. While I have no problem having the 2Xs in my ears for, say, two hours, after that length of time I do get the sense of having something in my ears that shouldn't be there. Unlike the competition, however, the 2Xs never feel obtrusive, probably because the material conforms to my inner ear better than the others.

The cost of the ProPhonic 2Xs is high (in addition to the $750, the molds will cost an additional $50 to $100), and because of their design, you have to purchase them on faith (and perhaps articles like this). It is impossible to try them prior to purchase, but Sensaphonics provides for one free remold if they don't fit properly the first time around. Their fit and finish is truly exceptional. Everything from the quality of the material used, down to the beautifully braided cable, makes these the best in-ear monitors I have ever seen. Finally, I have found a match for my iPod mini. I no longer have to endure the dreadful sound of the stock headphones, and can revel in the sound quality the little Apple provides. Danny Kaey

ProPhonic 2Xs
Retail: $750

Sensaphonics
web address: www.sensaphonics.com