OVC TC20

Enclosure type: closed, canalphones.
Frequency response: 20-22000 Hz.
Nominal impedance: 16 ohm.
Sensitivity: 104 dB/1 mW at 1 KHz.
Cable: fixed, straight, Y-shaped.
Price: $39 (ex. shipping).
On sale at Head-Direct, shipping costs US $3 within America, $10 to the rest of the world.

TC20 are canalphones made by Chinese Original Equipment Manufacturer (OEM) OVC.

If they look like Crossroads Mylarone, that’s because they are family - Mylarone are derived from TC20.

The pouch might look familiar to V-Moda earphone owners, OVC used to be an OEM for V-Moda.

Earphones are colour-coded, blue for left and red for right.

EQ

First off, the frequency response graph shows a typical canalphone picture - midrange and treble elevated over bass.

The fix for that is either a dampening EQ, dropping midrange and treble (which the canalphones themselves may not like, becoming a tad anemic and suppressed in response), or bass boost.

The Cowon T2 player has not one, but three means of boosting bass: “BBE”, which seems to add overtones corresponding to bass frequencies (and thus creating a psychoacoustic illusion of added bass response without actually boosting bass response); “Mach 3″, which is a goofy name for standard bass boost, and the equaliser. BBE+equaliser seem to be the best way to correct tonal balance, as the combination of overtones and equaliser doesn’t distort the frequency response of earphones like a powerful taming EQ, or saturate the low end like bass boost might.

…and the third, additional fix is a simple “mod” - a bit of acoustic foam over the canalphones’ driver meshes.

A set of old Panasonic headphones (killed by an Apple Powerbook - it overdrives headphones with an impedance lower than 32 ohm) provided the foam.

Tiny cuts of foam fit over the grilles, and are held in place by the tips.

Combined with the T2’s bass overtone boost and EQ, this little mod has made the TC20 quite powerful in the low end.

The Cowon T2 has a basic five-band equaliser, with sliders at 50, 200, 1000, 3000 and 14000 Hz. No clues as to the Q, but the gain range is displayed as +/-12 dB.

EQ was boosted by +1 dB at 50 Hz, dropped by -1 dB at 200, 1000, 3000 Hz; and boosted by +2 dB for 14000 Hz.

Bass overtone generator, “BBE”, was set at +1.

Fit & Hygiene

[22:33] S-Priest: Canalphones are teh masochism.
[22:33] Nickelas: does that make you teh masochist?
[22:33] S-Priest: “Teh Masochist Reviewer”.
[22:33] S-Priest: Hey, there’s name for a column.

And lo, here comes the most painful and masochistic part of this review. If there’s any problem with canalphones, it’s comfort.

Somehow canalphones always remind of either a medical device (canalphones are, after all, related to hearing-aid canalphones), or some kind of bugs crawling inside one’s ears. Munching on and/or collecting earwax.

The pouch provided with canalphones is not just for beauty’s sake. Ear canals are sensitive to alien bacteria, and can catch an infection. Canalphones must be cleaned regularly and stored inside a clean pouch.

Canalphone tips can be cleaned with hydrogen peroxide (special thanks to Eric J. from Head-Fi forums for the advice). Drug stores sell a 2-3% solution for around $2-3. Hydrogen peroxide dissolves any natural oils and earwax in a few minutes, after that the tips can be washed with water.

As for the fit… Well, they fit. They’re not as painful as some higher-end canalphones (more because of a tamer high-frequency response than physical shape), but the tips supplied are single-sleeve, differing only in width. So the TC20 may have to be inserted rather deep to hold.

And then there’s the eternal problem of earphones - pushing from within the ear canals. Pressure from within. Stuff stuck in one’s ears, literally.

That way, yes.

Acoustics & Sound

The TC20, like any canalphones, are very sensitive and can pick up small details off the weakest sources. They don’t need an amplifier to make noise, wow and flutter of a record transferred from magnetic tape stand out, or highlight microphone power supply hum not audible on speakers.

TC20 are not as clinical as higher-end canalphones, but they do lack some of the airiness, extreme detail, dynamics and presence of pricier models (like VSonic R-02 Pro, the more expensive canalphones Head-Direct sell; those could be recommended to a musician, unlike the “listener’s” entry-level TC20). Connected to an Audigy-2 soundcard, they sound precise (with the acoustic foam mod), though somewhat still and lacking movement.

Human hearing is echoical, responding to reverberation cues. A dry synthesised instrument sounds somewhat obnoxious and harsh exactly as it lacks harmonics and echoic reflexions which humans require to perceive a sound as a real sound. Effects like chorus and reverberation (and random delay) add a more natural body to a dry basic wave of a synthesised instrument.

Midrange and high frequencies are where the vitality of music is. To human perception, a record must have clean midrange and high (and very high) frequencies reproduced correctly with all the “subtle” reflexions and reverberation cues.

Unfortunately, CD audio becomes progressively harsher as frequency rises. That is not as noticeable with lower-end gear, but quite obvious with sensitive and precise equipment and headphones.

TC20 are quite forgiving. They may lack some of the airiness and spatiality of the more expensive canalphones or headphones, but they also don’t expose the harshness of compressed formats or CD audio as readily (Cowon T2’s EQ and DSP help with that too). With the right EQ and a bit of acoustic foam they can draw into music.

Music

There’s that interesting concept of synergy. Certain gear has a synergy with certain kinds of music.

Picnic are an art rock group based in St. Petersburg, Russia. Their music played almost “natively” with the Cowon T2 and OVC TC20, transmitting the darker, burning and philosophical essence of the city and the group’s art.Soft Cell’s “Desperate” and “Out of Love” played nicely; those two tracks off “Cruelty Without Beauty” are pretty much thumping basslines with voice, artificial percussion, and synth lines. Synth-pop as it is.Velvet Underground (”I Can’t Stand It”) did cause some feet-tapping and finger-snapping. Canalphones, like all headphones, can play percussion more precisely than speakers.Guitars might lack some “meat” to them, until low midrange EQ sliders have been dragged down to taste (200, 1000 & 3000 Hz in the case of Cowon T2). TC20 still sound somewhat toyish - they don’t provide the same “music zone” soundstage as real, circumaural headphones.TC20 lack some of the very high-frequency detail that distinguishes high-end headphones (and earphones). This very high-frequency detail (past 10 KHz) is what conveys ambience. But what they do play they play honestly, without any distortion or exaggeration, and they’re rather musical. A proper equalisation helps them a lot, and in fact, Crossroads’ derived Mylarone series might be just that - an acoustically tuned version of TC20 made to match a more harmonic frequency response.TC20 aren’t as precise or smooth-sounding as the other Head-Direct canalphone model, VSonic R-02 Pro. Next to the R-02 Pro the TC20 sound is thin and lacking sparkle, even somewhat metallic. They’re not very fit for music-making, either.

Conclusion

OVC TC20 are an entry-level canalphone model.TC20 used to cost $19 excluding shipping from Head-Direct on Christmas 2007 and Chinese New Year (February 9th this year). That price made them attractive as an entry-level canalphone, but at $39 there’s a lot of “portable” heaphone competition from AKG/JBL, Sennheiser, Koss, even Pioneer and Audio-Technica (and Roland).

OVC TC20 can be somewhat mechanical-sounding “out of the box”, without a correcting EQ.

TC20 pretty much require an EQ of some sorts to help with their elevated midrange and treble: either a “bass boost” of some kind for a portable player, or a more thorough adaptation of sound, as described in this review. With a proper EQ though, the TC20 will be musical in a somewhat distant way, which could be a plus for canalphones (canalphones always try to insert the soundstage “deep inside one’s head”).

Because of the low price, TC20 can be recommended as an introduction gift of sorts - they show what a detailed sound is like, and encourage experimenting with equalisation and digital signal processing. TC20 are an upgrade from “regular” player-bundled earbuds too, but at just $10 more the Yuin PK3 can be a much better and exciting option.