Sleek Audio CT7 custom earphone in Review – masterless sound

In 2009, Sleek Audio officially released the CT6, their first custom earphone. At its introductory price of 300$, the single driver earphone dominated the budget custom earphone world with great sound and a slew of innovations at a great price point. A LOT has happened since then, and while the CT6 remains a great earphone, it has been outclassed by newcomers. Naturally, Sleek Audio couldn’t leave it at the top of their portfolio. Enter the CT7, a completely redesigned custom iem sporting dual drivers, higher sensitivity, better artwork, and one of the rawest, fastest, most impressive sounds I’ve heard at any price.

Speaker type: ultra-wide band balanced dual armature driver configuration
Variable Equalization (VQ) Tuning
Wireless Hybrid (wireless unit sold separately)
50” detachable/swivel cable
Frequency Response: 18Hz.-20kHz.
DC Resistance: 25.4ohms
Impedance: 50 ohms
Sensitivity: 115dB

  • Price: 699$
  • Guarantee: 1 year
  • Production time: 2-4 weeks
Contact Sleek
600 8th Ave West, 3rd Floor
Palmetto, Fl 34221

T: +1 800.777.7937
F: +1 941.866.0626

Accessory and package
The CT7 is a custom earphone. You have to order it through Sleek Audio or a Sleek Audio partner audiologist. You’ll have to get gooey stuff squirted into your ears, then you have to ship those gooey things out to Sleek’s home in Florida. No matter who you buy from, there is very little variation on the scene. Sturdy pelican case: check. Detachable cable: check. Wax loop: check. Personalised foam inserts: check. Personalised, engraved name tag: check.

What? Personalised box tag and foam inserts, you say? Yes, I do say. Sleek Audio deserve their hard-earned whuffie because their custom earphones not only fit your ear, they fit your ego, too. Sleek Audio are the only company I know that completely customise their entire retail package. So, when I designed the robot skirt and trousers for my earphones, Sleek made cut prints on my earphones. I wasn’t expecting matching foam inserts, though. And just like before, Sleek personalised the box with the TouchMyApps logo. Yep, they are the kings of customisation.

Their new printing system is pretty damn cool, too. At CES this year, I saw some amazing examples of buffing systems, etching, and paint jobs. Of course, everyone has stepped up this year, but Sleek’s new system is top notch and comes with comparatively cosier price points.

From what I understand, Sleek also offer a soft-sided earphone wallet.

Fit and isolation
As an an acrylic custom earphone, the CT7 will nudge coolly wedge into your ear. Acrylic is hard, but don’t let that scare you off. Providing that you obtain good impressions, the CT7 will be as comfortable as an ear plug. It isolates about 26 decibels, which means you can keep your music at lower, safer volumes, and will never be bothered by the outside world.

Now, acrylic has one or two problems next to the silicon used by ACS and Sensaphonics, and the semi-soft fit employed by Westone. Namely, that is that the earphone doesn’t adapt to the changing shape of your ear canal. When you sing, talk, eat, whatever, your canal will change from round to oval, and vice versa. A lot of stage musicians use acrylic earphones and get on fine, but I promise you, it isn’t the ultimate choice. Semi-soft and soft iems adapt better for expressive singers.

For audiophiles and music lovers (generally, I prefer to separate these two since the latter tend to gear head around rather than enjoy their music), acrylic is simply the bomb. The hard material has the best-sounding echo for fast, clean bass and treble.

Build quality and cable
Message to Sleek: the CT7 cable HAS to change. It is horrible. The CT6 got away with its half-arsed design because of it’s price. Its cable was known to come unglued at the seems (mine did), crack, and in extreme cases, break open to reveal the wires. That was 2009.

You’d think that by 2011 things would change for the better. Nope. The current cable is by far the worst cable on any custom earphone I’ve seen yet. It is the same thing that comes with the cute 55$ Sleek Audio SA1. My SA1 cable failed after light use. It’s a bugger of a shame, too, as Sleek Audio’s coaxial cable connection system is one of the best in the industry. It fits firmly, sports a resilient earphone-side pin, and turns 360 degrees so you can use it up, down, sideways.

The cable will stiffen from sweat and body oil in short order. Its plug is a poorly-relieved straight-angle piece of metal that sticks out like creaky tower. The rubber sheath around it comes unglued and offers very little protection, as inside, the hard pylon that stems from the plug, pinches the cable at stern angles. The y-split is a cheap off-the-shelf sheath of aluminium with a rubber plug. At the ear, the CT7‘s rubber grommets are better than the those of the CT6, but alas, they’re attached to what is else wise, an unprofessional throw together of rubber and metal.

You can opt for the Kleer Wireless bundle, however, and forgo the horrible cable from the start. That option is unique to Sleek and a real boon to the system and Sleek’s amazing coaxial plug.

The good news is that otherwise, the CT7 is a well made earphone. It has thicker walls than its competition from giants Ultimate Ears and Jerry Harvey. It will survive falls better than those two. Of course, for stage musicians, acrylic is a liability unless you are very careful.

The dual Knolls drivers are anchored pretty typically, and the tiny crossover sits atop the larger driver like a cap. Like the CT6 before it, the CT7 can be custom-tuned to your preference, but unlike the CT6, it is pretty much perfect without any tuning at all. Tuning comes from widening or tightening the sound bore.

As you can see, the drivers sit deep inside the CT7 housing unlike FitEar, and Jerry Harvey earphones.

Want a nutshell sound review? Here goes: fast, tight, awesome, sensitive, wide, detailed, raw, pleasing, smile, trance, rock, great. It is a tweaked-for-the-better custom version of the Audio Technica CK10, my favourite earphone of all time.

The CT7 is everything the CT6 was, but better; it is in fact, everything the Jerry Harvey JH13Pro is but rawer. The first listen cut smile lines all over my face for that exact reason.

Gearheads: the CT7 has two speakers per side. It compares very well with earphones sporting 6 or more per side. If you want to brag, you can brag that your dual driver earphone sounds as good earphones with more drivers, and still save hundreds of dollars.

Let’s start off with bass. The CT7 bass attacks all its bases well, but excels in the difficult to control range of 70-200Hz. That range is drier than the bass of the aforementioned JH13Pro, standing out against the wetter, liquidy Earsonics EM3Pro. It is taut, energetic, and hard-hitting, but not abundantly thick. Thickness goes to the ACS T1. It hits with a handful more decibels’ impact than the CK10‘s bass does, vibrating deeply and strongly along the entire range. There is very little inflection at all in its range, though as the signal moves ever higher, the CT7 tends towards sugar, not spice. In other words, artificial bass of fast trance and IDM never abrades, lower percussion is tight and controlled, and there is plenty of detail.

It is fast, ferocious, and squeaky clean. Metal, not wood. No delay, no unwanted reverb in the sound tube. Bass belts out quickly, then fades just as quickly. It is much preferable to the ACS T1 for listeners who value neutrality and clarity.

The JH13pro and EM3Pro, on the other hand, present finer bass texture and space. If there is dead space between bass instruments, you will hear it more clearly through the CT7‘s more expensive competition. The JH13Pro is the champion here, painting low notes like the clearly defined hyperfocal lines of an old Nikkor 50mm 1,2 lens. The CT7 follows along, respectfully, delineating bass and mid voices perfectly well, but at the same time, presenting each within tighter spaces.

I don’t feel that there is a right or wrong here. The CT7 is blunter, the JH13Pro is finer. If you get used to one, you’ll find the other takes time to adjust to, but neither is better than the other unless you give most listening time to genres such as jazz and vocal, in which case, the JH13Pro is just sublime. For industrial rock, electronic, and classical, the extra bite of the CT7 is smashingly good.

The CT7‘s midrange follows its bass. It is forward, edgy, and fun. It’s got detail. It’s got space. It’s got bite. It even has softness where needed. You can hear very clearly the small wet sounds of the mouth, stray breaths into the microphone, the gnarled strings of a guitar. It’s all there.

Vocals are crisp, and guitars forward. Percussion is excellent from the toms to the high hats. Where the the JH13Pro softens, the CT7 tweaks. Natty drummers are natty, crappy guitarists are crappy. The CT7 isn’t sibilant, it’s honest.

Both male and female vocalists excel. They are clear and strongly rendered. The CT7 has a special affinity for mature, lusty voices. The likes of Melody Gardot and Madeleine Peyroux are perfect matches. Nick Cave follows suit. Even Dr. Dre sounds great.

Certain, scratchy voices, however, aren’t the best fit as the CT7’s honest voice will emphasise the scratches till your ears itch in all the wrong places.

Again, it isn’t a weakness, it is merely honest. Milk, not molasses.

If I were to attach a numerical value to CT7 vocal quality, I’d give it an 8. While the formula is right, higher pitches voices lack lust in comparison to the JH13Pro. Of course, the JH13Pro comes costs 300$ more than the CT7. It’s a trade off, one I think that rock, electronic, classical, and pop listeners can live with. Jazz and vocal listeners – if you really really want a custom, the JH13Pro is probably your best bet. The EM3Pro is as good if not better for that genre, but is overall warmer.

The CT7 has almost the perfect balance of power and tenderness. Its equals are more expensive than it. It’s price rivals generally have more audible tradeoffs.

Finally, I’d like to talk about one of the biggest changes between the CT6 and CT7: sensitivity. The CT7 is on par with the FitEar Private 333. If there is any hiss in your source, no matter how timid, you will hear it. The iPod touch 4G is by far the quietest reasonable source I’ve head. It makes no background noise with 99% of the earphones on the market. The CT7 are that 1%. It’s not annoying, it’s surprising. Usually, classical music is dead silent with my CK10, JH13Pro, EM3Pro, Westone 4, and everything but the Private 333.

On the flip side, I can keep the touch on a volume setting of three to four no matter what airplane I’ve boarded. Incredible. Again, I don’t listen to loud music, but even so, the CT6, CK10, and JH13Pro are generally set to as much as 50% of the volume slider.

And, if you have a modern iPod or iPhone, you don’t need an amp to get all the detail you crave. There is a small amount of bloom in the lower bass region when driven without an amp, but it is minimal. Treble notches out to the tune of 2 or 3 decibels way up top only to recover again quickly. A good amp may get everything perfect, but I doubt the difference is audible in controlled, blind listening. Well, actually, since most amps output much much more background noise than an iPod touch, the difference will be audible – and probably not savory.

Out and about
Despite a deep disrespect for Sleek’s crappy cable, I’ll have to admit that it works well for the commute. It is dead silent, light, and unobtrusive. Sure, it tangles, but all good cables tangle. It is long, thin, and because it lacks memory wire, is perfect for glasses wearers.

The cable is long enough to comfortably drop into a pocket or purse, and of course, it can go wireless to a comfortable distance of 10 metres with Sleek’s Kleer Wireless accessory.

Sleek outdid themselves again, making a perfect-sounding earphone for the price point. The CT7 shines with everything you throw at it, even in comparison to pricier juggernauts. If you love music and have 700$ to invest in a near custom earphone, the Sleek Audio CT7 is probably my first recommendation. It has slid ahead of the FitEar Private 333 as my overall favourite for electronic and trance. The CT7’s guitars, too, are to die for. There’s so much going for it that the crappy cable really sticks out, sore and red.

If Sleek can ship a professional cable worthy of the CT7’s 700$ price tag, they’ll have the must-have custom on the market. I unreservedly recommend it to kiddy-gloved music lovers, but scorn its shoddy cable.

Wonderful sound
Best customisation
Good build quality
Incredible accessory package

Horrid cable

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