Headphone Reviews

When testing headphones with multiple listeners—our standard practice at S+V—I've learned that perceptions of a headphone's tonal balance can differ among listeners. Of course, individual taste in sound varies, too.

One solution to this problem is a headphone that can be tuned to the user's taste, a feature we've encountered on in-ear monitors from AKG and Phonak. Both have interchangeable filters that can alter the headphone's tonal balance. But the former costs $1,299, and the latter uses extremely tiny filters that require a special tool to change.

A new company named Torque Audio has what looks like a more practical approach.

The company's $179 t103z includes three sets of color-coded tone filters that are large enough to change with your bare fingers. The filters can be stored by threading them into the TorqueValet, an aluminum bar with graphics that show each filter's function. The TorqueValet even has a filter wrench at the end. The company calls this feature Passive Acoustic Valve Technology (PAVT).

The red filter is called the reference valve, and is said to give a flat response. The black filter is called the clear valve, and is intended to deliver "sparkling, crisp highs." The yellow filter is called the deep valve, and is said to give "high octane, full throttle bass." Replacement valves are available for $19.99/pair, and the company plans to sell more filters with alternative tonal options. The website shows a green filter called the balance valve, with "smooth lows and detailed highs," and the company plans at least one more option.

A cynical enthusiast might dismiss this (and a savvy entrepreneur might applaud this) as nothing more than a scheme to extract more money from customers. But one could also look at it as insurance, giving the customer a much greater likelihood that he or she will find an appealing sound—especially considering that one rarely gets a chance to try an IEM before buying.

Besides the filters, the t103z is a fairly conventional but nicely made design. The earpieces are machined from metal and contain 10mm dynamic drivers. The inline mic/remote is compatible with iOS devices (iPhones, iPads, etc.). The package includes single-flange silicone tips in three sizes, plus double-flange tips in medium size.

One thing I can say for sure about Torque Audio's concept: It's easy to grok. To demonstrate it to our regular West Coast headphone panelists, Lauren Dragan and Will Huff, I didn't say a word. I just pulled the silicone tip off one earpiece, twisted the filter off, pulled a different filter off the TorqueValet and threaded it onto the earpiece, then showed them the graphics on the TorqueValet. Both of them immediately got it—and both lit up with huge smiles.

While Will and Lauren found the filters easy to change, both complained that the single-flange tips were too difficult to remove, Will worrying that he might damage the tips, Lauren saying that it would make her less inclined to change filters to suit different music or listening environments. I, too, found the single-flange tips a little on the tight side, but imagine they'll loosen up with repeated changes. None of us bothered using the wrench built into the TorqueValet because the filters were so easy to tighten with our fingers, but I was disappointed to find that the wrench was too small to fit the black and red filters—a production snafu, I imagine, especially considering that our test sample was one of the very first off the line.

Otherwise, all of us found the t103z comfortable to wear and easy to use. "I could barely tell they were in my ears," Will said. Will and Lauren, who used the t103z with their iPhones, found the inline remote unusually friendly, and especially easy to use by feel. One headphone, three sounds

Lauren and Will both worried that they'd have trouble perceiving the differences among the filters, but the first filter change proved to both of them that the effects are easy to hear. For example, Will described the sound with the red filter as "breathtaking," but likened the sound with the black filter to KFI AM 640, a Los Angeles talk radio station.

Because Will was the most enthusiastic about the t103z, I'll let him rave a bit. "Of all the headphones we've tested, this is the first I've rated 5 stars," he said, talking mostly about his experience with the red filters installed. "When I started out by playing Haley Reinhart's version of 'House of the Rising Sun,' I got chills. I thought it was a anomaly, so I played it again later, and I got chills again. I prefer a sound with equal power in all octaves, and this gave it to me. When I played Queen's 'Bohemian Rhapsody,' I got the most lifelike percussion I've heard, short of standing next to a drum kit on stage."

I, too, preferred the sound of the red filter. Inspired by Will's listening choices, I put on Meshell Ndegeocello's ultra-upbeat version of "House of the Rising Sun," and was impressed with the t103z's clean, well-defined, precise, resonance-free sound. Pop music such as K-pop boy band Big Bang's "Haru Haru" sounded fantastic, with all the voices and instruments clear and distinct, and an exciting but not exaggerated sense of ambience. The bass with this filter sounded very close to perfect for me: tight, defined, punchy (but not excessively so), and in perfect balance with the mids and treble. With most of the rock and pop tunes I listened to, the red filter delivered the same result: a clean, straightforward, unadulterated sound.

More demanding material, such as that old standby, Steely Dan's "Aja," left me with the impression that I might like to hear a little more energy in the upper mids, around 1.5 kHz (which would give voices and guitars a bit more oomph), and perhaps a couple dB less energy in the upper treble (around 8 or 9 kHz) to make the cymbals and other high-frequency instruments sound a little less zippy. Perhaps there'll be a future filter that gives me that option?

Lauren preferred the black filter, saying that it "balanced the bass and created more presence in the sound." My reaction to the black filter wasn't as negative as Will's. It definitely sounded too thin for my taste, but I bet it will appeal to a lot of audiophiles, who tend to like lots of detail in the treble.

The yellow filter was on the opposite end of the spectrum. Will found the sound almost as appealing with the yellow filters as with the reds, saying that the yellows had everything the red filters had but with a softer sound, slightly muddying the mids. Lauren dismissed the yellow filter's sound as "like a boomy club." For me, it was like listening to a home theater system with the subwoofer turned up +6 dB too loud; the mids and treble sounded good but were obscured by booming bass. It seems to me like an attempt to deliver a Beats-like sound, although with a somewhat smoother and more pleasing overall result. Measurements

To measure the t103z's performance, I used a G.R.A.S. Type RA0045 ear simulator, a Clio FW audio analyzer, a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface, and a Musical Fidelity V-Can headphone amplifier. Measurements are calibrated to ear entrance point (EEP), the point where your ear canal intersects with your earlobe. I used the standard, single-flange silicon tips in the medium size because these 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 did most of the measurements of the t103z with the red filters, then tried measuring with the other filters for comparison. As you can see in the first frequency response plot, the response of the t103z is unlike any other we have measured. There's a sizeable upper bass/lower midrange bump centered at 300 Hz, a slight lower treble peak at 2 kHz, and a very narrow peak at 10 kHz. With a typical IEM, we'd see a broader bass bump between, say, 40 and 300 Hz, a strong peak at about 3 kHz, and perhaps another peak at 6 or 8 kHz. The response with the red filter is so far afield from what I've seen in the past that I wouldn't venture a prediction as to its psychoacoustic effect—I'll just have to let the panelists' subjective judgments stand on their own.

As you can see in the second frequency response plot, the effects of the filters are considerable. The response curve of the black (high-pass) filter is fairly similar to the red (flat) filter, with a little less bass response and +7 to +8 dB more treble response above 3 kHz. The response of the yellow (low-pass) filter is radically different, and much more similar to the measured response of a typical IEM; it's almost the same as the response of the red filter except that it has a much larger and lower bass boost that peaks at 60 Hz.

(Post-script: After this review was published, I had a chance to discuss these measurement results with a Torque Audio representative, who said that the results were essentially the same the company had gotten. He postulated that the G.R.A.S. coupler commonly used to measure in-ear monitors may be incapable of accurately measuring IEMs with ports. The red and black filters are both ported while the yellow one is not. Thus the disparity between the measured response of these filters—especially the red one—and our panelists' subjective impressions. I can't say without further investigation whether or not this is correct, but it's certainly a plausible explanation.)

Adding 70 ohms output impedance to the V-Can’s 5-ohm output impedance to simulate the effects of using a typical low-quality headphone amp has no significant measureable effect.

Total harmonic distortion (THD) at 100 dBA is just a bit higher than we usually measure with IEMs, hitting 4% at 100 Hz and maxing out at 5.5% at 20 Hz. Isolation is typical for an IEM. With the single-flange medium tip, it's -10 to -29 dB above 1 kHz. Switching to the double-flange tip improved isolation by -5 to -10 dB above 3 kHz, but that result reflects the way the tips fit the G.R.A.S. coupler; results with your ears will likely vary.

Measured impedance is just about dead flat at 15 ohms. Average sensitivity with a 1 mW signal at 16 ohms rated impedance is 102.4 dB from 300 Hz to 6 kHz. Bottom line

No matter which of the t103v's valves you prefer, there's no question that this is the most user-friendly application of the interchangeable filter concept to date. The t103v is a well-engineered, thoughtfully designed headphone in its own right, and the addition of the filters makes it vastly more versatile than almost any other IEM on the market today. We're eager to hear what the upcoming filter sets sound like, too.

Meanwhile, I think we can all agree with Will's summation of the t103z: "We music lovers deserve to have stuff like this."