Celsus Sound is a relatively new company that has exactly two current products: the Companion One portable player ($595) and the Gramo One open-back earbuds ($249). Both are aimed squarely at the high-performance portable player category, and both promise high value. This review will focus on the Gramo One earbuds, which are certainly the best looking and performing earbuds I've tried. However, since earbuds are my least favorite earphone design, don't reach for your charge card quite yet.
First, what exactly is an earbud, and how does it differ from an in-ear, on-ear, or over-ear headphone? Anyone who has ever purchased an iPod or iPhone has become the "proud" owner of a pair of earbuds. Unlike in-ears, which go into your ear canal and are held in place by your canal, earbuds rest in the outer hollow of your ears and don't make contact with your ear canal. People who hate the feeling of something in their ear canal often love earbuds. Others, like myself, dislike the vague fit of an earbud and the fact that, if I move my head, the earbuds move in position and their sound changes. A thin foam sleeve can be used so that the earbuds slip less; but, even with the foam sleeve, they still flop around in my ears. If you are pro-earbud, read on. If you are anti-earbud, I suggest looking at one of my other earphone reviews because you will dislike the Gramo One's fit for the same reasons you dislike the Apple earbud's fit.
The Gramo One earbuds come with a soft pleather case and a pack of six foam sleeves. I found the sleeves invaluable to the earbuds because they reduce slippage. The cable is permanently attached; with most designs, this would be a negative, but since the Gramo Ones only rest in your ear hollow, even a half-hearted yank will eject them from their resting spot before it stresses out the cabling. The cable is 1.2 meters long, which might be slightly long compared with many portable cables I've seen. However, since the cable is not interchangeable, a bit too long is much better than too short.
The heart of the Gramo One is its proprietary 16mm transducer. With a 32-ohm impedance and 100-dB sensitivity, the Gramo can be driven by almost anything that plays music. The published frequency response is 15 Hz to 23,000 Hz, although I've got to wonder how they got that 15-Hz figure given the variability of bass response based on fit.
I've written here and on Audiophile Review's website about how important a headphone's fit is to its performance. A good-fitting $100 pair of earphones can be far more satisfying than a poor-fitting $500 pair. As I mentioned earlier in the review, if you find the fit of Apple's earbuds to be acceptable, you will find the Gramo's fit to be very similar. Sonically the Gramo One has the potential to leave the Apple earbuds far behind.
For everyday to-and-from work commuting on public transportation, the Gramo One earbuds are a mixed bag. First, they lack any iPhone or other smartphone controls; so, if you are using them with a smartphone and a call comes, you can't merely push a button on your headphone cable to switch to phone mode. Also the Gramo One is not designed to supply any isolation from the outside world. In a noisy environment, that makes it less than ideal unless you really need to hear what's going on around you, in which case wearing any kind of earphone might be counterproductive.
Celsus calls the Gramo One "a reference-grade open-back earphone designed to replicate an audiophile's dream sound system." Unless the fit is perfect, this may be a stretch. If you are looking for an "out of head" experience similar to what you hear from a room-based system, forget it--the Gramo's imaging isn't any more "outside your head" than any other in-ear design. The Gramo does have less imaging specificity than in-ears like the Etymotic 4P. The edges of instruments and vocalists are less precise than with many headphones.
When it fits right, the Gramo One can sound borderline awesome, with excellent bass extension and stunning midrange clarity. For me, though, that fit was elusive. If I pushed the Gramos in, ever so slightly, they sounded well balanced and dynamically responsive; but, unless I held them in place, they would shift slightly, and the sound would change for the worse. I wish that Celsus made a headband for the Gramos. Don't laugh, Stax did exactly that for their SR-001 earbuds.
• The Gramo One earbuds have excellent build quality.
• High sensitivity makes the Gramo One a good match for smartphones.
• The sound is well balanced when the Gramo One is worn properly.
• A good fit may be elusive for some users.
• The Gramo One lacks any control functions for smartphones.
• The Gramo One does not isolate the listener from outside noises.
Comparison and Competition
Earbuds typically occupy the lower end of the price spectrum. The Gramo One is one of the few earbuds that attempts to match the performance of an in-ear design. Given the importance of the fit, the overall sonic performance of the Gramo One can and very likely will be different from person to person, just as with other earbuds. Whether the Gramo One is worth $249 depends on whether you prefer earbuds to all other compact earphone designs and whether you like the Gramo's fit.
Most earbuds are not designed to sound great, but merely to work. The Gramo One is an exception. Celsus' design goal was to create an earbud that was sonically competitive with other styles of earphones. For me the Gramo Ones did not live up to their potential--not because of their native performance, but because I could not achieve an ideal fit. However, if you are a resolute earbud user who prefers earbuds to in-ears, I heartily recommend you give the Gramos a try--they could be your dream earbuds.