Review: Phiaton PS210 BTNC Headphones

Gadget freaks can drive themselves crazy waiting for the perfect product. Whether it's a smartphone, an A/V receiver, or a laptop, it seems there's always at least one missing feature that you really, really need.

If you're into in-ear monitors (IEMs), the perfect product may have finally come along. Phiaton's PS 210 BTNC builds on the winning concept of last year's PS 20 BT Bluetooth IEM by adding three great features: active noise cancellation; a sleeker design made from stainless steel; and a 3.5mm input that lets you use the PS 210 BTNC even when its internal rechargeable battery runs out.

What more could you want in an IEM? Balanced-armature drivers, maybe. Or even six or eight balanced armatures. But if you're happy with plain ol' dynamic drivers (and we often are), the PS 210 BTNC pretty much has it all.

The PS 210 BTNC's electronics are packed into a little box that clips onto your clothing. The box has numerous controls: a power/hold switch, a noise-cancellation on/off switch, an answer/end call button, and a nubby joystick that controls volume and track skip forward/reverse. On one end of the box, there's the 3.5mm input jack plus a micro USB jack for charging. (Incidentally, the wired input capability is dubbed "Everplay-X technology," surely the most grandiose name ever applied to a 3.5mm input jack.)

The earpieces use the same half-in-ear design as Phiaton's other IEMs. A large flange in the middle of the earpiece helps occlude your ear to get a better seal, deeper bass, and a more consistent tonal balance. It doesn't work well for everyone - S+V web editor Michael Berk [ed: forgive me, just doesn't work for my undersized ears!], for example - but I love it. The drivers inside the earpieces are relative jumbos, measuring 14.3mm in diameter compared to about 10mm for most dynamic IEM drivers. Further increasing the chances of getting a good seal are silicon ear tips in four sizes plus a pair of Comply foam tips.

Based on my super-positive experiences with past Phiatons, I expected to like the PS 210 BTNC. To get some different opinions, I called in two of our frequent headphone testers, L.A. voice actress Lauren Dragan and jazz musician Will Huff. Lauren compared the PS 210 BTNC to her new reference 'phone, the PSB M4U 2, while Will and I compared it to various other headphones we had on hand. We used our various source devices, including iPhones, Droids, and my iPod touch, all connected through Bluetooth.

Lauren wasn't thrilled with the fit and sound of the PS 20 BT, but she warmed right up to the PS 210 BTNC, calling it "comfy." Whether she's finally getting used to the half-in-ear concept or the PS 210 BTNC's subtly different design worked better for her, I'm not certain. Her only ergonomic complaint? That the PS 210 BTNC's volume control doesn't work in sync with her iPhone's internal volume control - i.e., even if the iPhone's turned full-up, you'll get no sound if the headphone volume's all the way down. Will called the fit "weird at first, but I got used to it." I of course loved it, and had no problem figuring out the PS 210 BTNC's various controls without consulting the manual.

Headphones 1, Jet Engines 0

My first experience with the PS 210 BTNC was brief - just a short flight from LAX to SFO - but that 45 minutes was enough to tell me I was plugged into a refreshingly awesome product. I started with a high hurdle: the magnificent An Evening of Jazz with the John Harmon Trio, one of the best piano trio recordings I've ever heard.

Harmon's pensive performance of "For All We Know" demands a quiet environment to be fully appreciated, and the 737's turbofans were no match for the great seal made possible through the half-in-ear design and the large silicon eartips, and the PS 210 BTNC's effective active noise cancellation. I could hear all the subtleties of Harmon's playing, as well as the delicate scrapings of the brushes against the snare head, and I got a good sense of the recording's super-spacious ambience.

Encouraged by this minor triumph, I quickly went through eight or 10 of my favorite test tracks, and was thrilled with the natural tonal balance, the huge sense of space, the treble detail, and the precise-yet-satisfying bass. The sound reminded me of what I heard from the B&W C5, and that's high praise indeed.

Will was enthralled with the PS 210 BTNC's performance. "The great isolation makes the sound so clean. It's very flat and neutral-sounding. I normally prefer something with more treble, but these are spectacular. When I was listening to high-pitched voices like the Bee Gees, the sound really came alive - I could almost see them in front of me. The bass isn't deep, but it does sound accurate."

Lauren largely agreed, calling the sound "really nice overall," even though she felt that switching on the noise cancellation feature made the mids and highs a bit less articulate. "But that's normal for NC," she added.

She also noticed a subtle, high-pitched whine with the NC activated, but I couldn't hear it (although she's 20 years younger than me and female, so her high-frequency hearing is surely superior to mine). No matter how good your hearing is, though, you won't hear a significant tonal balance or level shift when you turn NC on and off.

Nor, even more surprisingly, is there a big difference when you switch from Bluetooth to a wired connection. I tried this with my Motorola Droid Pro smartphone, which has a sub-par headphone amp with a very high 75-ohm output impedance. I expected the sound to get dull when I switched to the wired connection, but it actually got a bit more lively, with slightly more vivid highs. BTW, noise cancelling works in wired mode - a convenience I didn't expect.

Most few headphone makers seem to assume you'll use a noise-cancelling headphone with NC on most of all of the time, so they focus on that and don't put much effort into getting the sound right when NC is off. The same could be said of some Bluetooth headphones that also offer a wired connection. We're impressed that Phiaton didn't make these lazy assumptions, and took the trouble to make sure the PS 210 BTNC sounds good no matter how you use it.

The only feature that didn't impress me is the inline microphone, which is built into the electronics box. Obviously, it delivers better performance the closer you get the mike to your mouth, but I found it cumbersome to clip the box way up by my mouth. I called a couple of people using the PS 210 BTNC and both said the sound wasn't particularly clear. You could unclip it and hold the box near your mouth if you need to, though.


I measured the PS 210 BTNC using a G.R.A.S. Type RA0045 ear simulator, a Clio FW audio analyzer, and a Musical Fidelity V-Can headphone amplifier. I used supplied medium-sized silicon tips, which fit the ear simulator best. I inserted and reinserted each earpiece several times, and settled on a position for each that gave the most representative result. I fed the headphones signals through the Everplay-X 3.5mm input and from a Sony HWS-BTA2W Bluetooth transmitter.

The PS 210 BTNC's frequency response measurements are a little different in Bluetooth vs. wired, and with NC on and off, but the general characteristic common to all is a peak centered at 2.1 kHz. This sort of peak is common in headphones considered to have a subjectively flat response. However, with most subjectively flat headphones, there's a bigger dip around 1 to 1.5 kHz - more like -10 dB than the -5 dB we see here.

There seems to be a significant difference in measured response between right and left channels, which persisted no matter how I inserted the earpieces into the simulator, and no matter what mode the headphone was in. Relative to the right channel, the left has a boosted response below about 700 Hz, peaking at +2.7 dB at 100 Hz.

True to our subjective evaluation, the PS 210 BTNC measures a little better in wired mode, with a -3 dB point of 33 Hz in wired mode and 46 Hz in Bluetooth mode with NC off, and about +4.3 dB more treble response at 6 kHz in wired mode. But there's almost no difference in response with NC on and off, just a mild bass boost with the NC on that maxes out at +2.7 dB at 20 Hz.

Impedance in wired mode is nearly flat, averaging 36 ohms and sweeping up to a max of 51 ohms at 20 Hz. As expected, the impedance rise in the bass affected frequency response slightly when I added 70 ohms output impedance to the V-Can's 5-ohm output impedance to simulate the effects of using a low-quality headphone amp, boosting bass at 20 Hz by +2.4 dB.

Total harmonic distortion (THD) at 100 dBA is very low, below 1% above 100 Hz and rising to just 2% at 20 Hz. This is measured in wired mode; due to the latency of the Bluetooth transmitter and receiver, I wasn't able to measure distortion in wireless mode.

Because I used an ear simulator instead of a full ear/cheek simulator to measure the PS 210 BTNC, I wasn't able to get the advantage of that big flange on the earpiece when doing isolation measurements. (I don't use the ear/cheek sim for IEM measurements because it's difficult or impossible to get a good seal with the ear/cheek sim's fake rubber ear.) So your results will likely be a little better than what you see here. Isolation without noise cancelling is about average for an IEM. Switching on NC reduces low-frequency noise by a maximum of about -20 dB at 250 Hz - so it's not as effective over as broad a band as most NC headphones I've measured, but in the effective band, the noise reduction is about +10 dB better than average.

Sensitivity in wired mode, measured with a 1 mW signal at the measured 36 ohms impedance, is 104.8 dB average from 300 Hz to 10 kHz, 106.5 dB average from 300 Hz to 6 kHz.

Bottom Line

Because reactions to headphone sound are so personal, it's not often we can wholeheartedly endorse a headphone, but the Phiaton PS 210 BTNC has earned our enthusiastic recommendation. It's such a rare treat to see an audio product - any product, in fact - in which every important feature and function has been completely thought through. We bet even Steve Jobs would have given this headphone a thumbs-up.