ACS T1 Custom-Fit IEM in Review – the perfect silicon implant

Ever been so enamoured by a new gadget that you take it to bed wrapped in your favourite dainties? I have. My lecherous fingers have caressed many pieces of technology, late into the night. But until now, they’ve been trained on MD players and really high tech shoes and my iPod touch 2G. I’ve tickled the ACS’ T1, an earphone whose quality belies its silicon shell, far into the dark night. Its sultry curves, great bone structure, and whip-strong cable cry to be handled in a Wash-like ‘manly fashion’.

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  • Active Drivers 3
  • Build Materia - 40 Shore Silicone with SteriTouch
  • Mould Type - Full Concha
  • Cable Type - Kevlar reinforced with anti-friction sheath
  • Standard Cable Colour Translucent
  • Standard Colour Clear
  • Connector 3.5mm gold plated moulded
  • Standard Cable Exit Top (over the ear)
  • Frequency Response 16Hz ~ 20KHz
  • Noise Isolation 26dB
  • Impedance 17 Ohms
  • Items Included Carry pouch, personalised rugged case, wax pick, care and usage instructions, comfort cream, step-up jack connector adaptor

Package and Accessories
To be honest, I don’t get off with just any earphone. The T1, however, clothed with the best custom earphone accessory package, is 100% satisfying. There are the usual suspects: the manual, a wax cleaning loop, and the carrying case – which thank the Lord, is a small-sized Pelican. And what sexy earphone would be complete without personal lube? The T1 even has that.

Also, a compact leather wallet that fits inside the Pelican case makes a great appearance. The T1 can be wound up and stuffed into the wallet and still take up less pocket space than an iPod touch. Most customs are built up from hollow acrylic shells which have a higher risk of cracking or shattering. Of course, when taken care of properly, they should last years, but silicon affords extra protection for the wearer. The T1’s silicon is its own protection; the earphone bends and squishes, all the while protecting is precious cargo: the tiny speakers and crossover network.

Silicon custom earphones are special. They fit snuggly, they bend, and they block an excessive amount of noise. But, they take longer to stuff into the ear. That is where the lube comes in. Apply a smallish drop to each earphone, massage it around, and then slip the earphone in. If you’re in a pinch, saliva, or excessive earwax will also work.

The T1 is a dual-bore design, but utilises three balanced armature speakers, so one sound bore will carry the sound from two drivers. Like the FitEar Private 333 and Sleek Audio CT6, the drivers sit fastened into the earphone’s body, not the sound arm. The cable is no less outstanding. Strong, thick, and resistant to sweat and body oil, the ACS T1 is built to last. The cable portion which loops over the ear lacks memory wire, so it is comfortable even for four-eyed audiophiles.

Finally, while I don’t suggest doing it, the T1 can be used for sleeping.

Finish and Build Quality
Overall, ACS have done a great job. Their T1 is smooth, solidly built, and can even sport a logo. As long as you can create in one colour and aren’t expecting a Monet, ACS’ technicians do a great job of customising their earphones. On my unit, the contrasty TMA logo looks pretty good against the all black, doesn’t it? I have no idea if newer units have cleaner lines or not; as you can see, the TMA is ‘wavy’, the headphone logo squiggling along the silicon shell. One thing you should be aware of is dust. Silicon shells pick up dust. Gently moistened fingers, however, are all that are needed to wipe dust away.

The T1’s cable is resistant to crystallisation and sweat and fraying. It is also excellently terminated in a right-angle 3,5 mini plug which will even fit into the iPhone 2G’s recessed headphone port. I am so convinced of its strength, that I’d wager my horse that there isn’t a stronger stock custom cable on the market; it might even support my body weight.

In one area, however, it performs below my expectations: the cable doesn’t detach from the body. For cute audiophiles who want to try different cables, it means a lot of money saved, but for professionals — especially considering that road/show life can be hazardous — it can be a liability. Even ACS’ stodgy and excellent brother, Sensaphonics, moved to a detachable cable system last summer. While I have every faith in the ACS cable, I don’t have the same faith in the professionals who can angel-of-death through rubber and wire in the passion of a hot song.

For years now, Triple driver earphones have been the de facto standard for audiophiles and professionals alike. But even with eight-driver earphones such as the JH16Pro eating up the the press, a triple driver’s elegance and keen temperament is what keeps its teeth sharp. The smooth and balanced T1 is an excellent example of how well-tuned a triple driver can be. It enjoys a broad and powerful midrange, smooth acoustics, and low and high extremes which are tweaked just enough to work with the ear’s own equalisation.

When driven from warm sources, at times, the T1’s bass blooms, but primarily, it settles warmly and well mannered into the low frequencies. Its full-bodied bass texture is a unique mixture of ambience and structure. Evident in Markus Schulz’ Mainstage, subwoofer levels flutter unperturbedly just shy of the level of some dynamic-driver earphones.

Overall, the soft silicon acts as an excellent resonance chamber. Even fast mid-bass in trance and drum and bass is nigh on perfectly controlled. With warm sources, the T1 has a layer of barely-audible echo in its mid bass – quite like adding 300 cc of vodka to party punch: no one knows why, but things are ever so much funner, and just a little out of hand. Non-bass driven music such as acoustic, rock, classical (the list could go on and on); and slower genres like hip-hop get on without perturbation. Trance, with its fast bass is the only slightly ‘off’ sound. The T1 throws a modest – and I do mean modest – extra wave of bass impact into each beat. It’s not chaotic, and for those who value a fuller, ‘rounder’ sound, it is great, but my brain has been conditioned on the sharper contrast of the FitEar Private 333.

Rock and hip-hop fans are in for a treat: the full, powerful bass bloody rocks. Packed under the T1’s bonnet are the most important elements of a sub-woofer: vibration and ‘POW’! On Hip-hop and rock, the slight echo makes everything more “rock’n roll”; bass guitars and kick drums have more twang. Even duffy duff bass from duffy duff recorded hip hop is full and round. In classical and jazz, though, there is a special magic. There is lots of space between lowly-voiced instruments, and great vibrations. It’s very much like listening to a valve amplifier: warmth, reverb, atmosphere – the T1 serves intense, yet refined piano and smooth strings. While it parties hotly with trance, it leaves the dress on the floor with rock, hip-hop, jazz, classical, and acoustic musics where its bass warmth can really show off.

So bass is voluminous, detailed, and painted with a bit of echo as it stretches up to the midbass. Where the T1 really, really sings is its milky-smooth midrange. The T1 is rich. Go ahead and follow my lead: sync up Feist’s albums, Let it Die and Surrender. Both albums rely heavily on guitar, hand-percussion, and piano. And, both have the tendency to lose a little magic from most of my other custom earphones. Not so with the T1. Feist’s voice, in smooth luxurious timbre, is perfectly haunting. The soft but thick pelting of the T1’s lower bass, the mid range vocals and instruments are catered to beautiful, relaxing, listening. Ticking with keen shimmer in the background are the perfectly decaying cymbals.

Overall, mid/high-pitched voices are most at home from the T1. Female vocals, Paul Simon (and the like), horns, strings: each are brilliant. Male vocals come in two flavours: amazing and damn good. Deep, throaty voices could benefit from the harder inner sound tubes of the FitEar and Jerry Harvey earphones, but lose only a little in comparison when rumbling from the T1.

Coming from the Sensaphonics 2X-s, an incredible, but somewhat fatiguing custom earphone, I was worried that the T1 too, would suffer from grainy treble. I couldn’t have been more wrong. The T1 extends beautifully high, and even appears to accommodate the ear’s ~8-10 kHz attenuation peak very nicely.

There is an abundance of clear, lush treble. In particular, cymbal and piano decay is spot on, never concocting strange, painful shimmers. To top it all off, instrument separation is excellent. From top to bottom, the T1 is free of smear and intermediate chatter.

Live recordings are spacious and mesmerising. Honestly, I am surprised. My experience with smooth earphones is generally tainted by a longing for more detail, more separation, more space. The T1 meets all my demands, and while not razor-cutting the image like the extremely wide FitEar Private 333, it doesn’t play second fiddle to anyone else. Between notes, there is just so much atmosphere and stage.

Headstage and hiss
The soundstage is ‘softer’ than some of the competition, cleansing away recording artefacts – a strange ability for an otherwise detailed earphone. Jerry Harvey’s JH13Pro retains the most coherently 3D image of any custom I’ve used, and the FitEar 333, the blindingly widest, but the T1 is close to both, adding the warmth and throb of a silicon earphone.

Instrument separation is succinct without engulfing the listener. In particular, the midrange stands out with powerful, dynamic soul. Club, trance, and live music is wide, but never loses that soft, recording-studio maturity.

The T1 is sensitive – make no doubt about that. And because its silicon construction shuts out more outside noise than acrylic earphones, source volume can be tipped downwards. A drawback of this is that if that source is hissy, you’ll hear it. Saying that, it should be noted that the T1 isn’t as sensitive to hiss as the FitEar Private 333 – which is a blessing. The background noise of an iPod touch 2G, which is among the lowest of all DAP’s, is faintly audible from the T1. My Fuze is next, casting more noise into the music, and my Sony A845 and AMP3 Pro 2 make angry noise in the background of every album I have.

Out and about
Remember that this is a fully custom earphone. If you really really want a 20 centimetre cable, go ahead – ring up ACS’ president, Andy Schiach, and tell him. Mine is ~170 centimetres; I can almost wrap it around my growing mid-section a couple of times! Definitely tell ACS what length you prefer. I tend to think 130-140 cm is about perfect for portable use: equally servicing jeans pocket stuffers, and purse-toters.

The cable is also energetic and needs the neck cinch. It doesn’t flop away from the ears, but there is some noise which travels up and down its length. With the cinch in place, however, touch noise disappears. Personally, I’d trade a little noise for strength and resistance to sweat and body oils.

Perhaps the best out and about feature of the T1, however, is the fact that it sits so flush IN the ear. It disappears in everything: the ear, in the wallet, and when not in use, in the trousers when packed together with an iPod nano! Its compactness combined with the solid silicon shell means no wind noise when exercising. The one area which can be annoying is when removing/inserting it. If someone bothers you with a question, you won’t like taking the T1 in and out – silicon earphones simply take more time to insert and remove.

There’s no escaping the warmth of the ACS T1. But where most warm earphones lose details and tend to boom, the T1 maturely casts everything back to the listener. Sure, there is a bit of mid-bass boom, but for most genres, it fits in perfectly. Otherwise, voicing is great and mid/high voiced instruments are phenomenal. That isn’t to say that bass isn’t as amazing. It is, but there, in the depths, is a warm, free-spirit lurking. It is warm, deep, big, and at times, accompanied by a faint second voice. If you are a fan of valve amplifiers, of LP records, and soft ice cream, you will probably enjoy the T1 a lot more than you will its competitors. Still, it stands toe to toe with them in majority detail retrieval.

Finally, It is strong, looks and feels great, and is nearly flawless for out and about. The only thing ACS could improve on is the cable’s attachment to the earphone; removable cabling would be perfect for both the experimental audiophile and the violent professional musician alike! If you are a performer, the soft silicon, which flexes and re-moulds itself to the inner ear, is a perfect choice for the stage. For the lecherous techies and audiophiles, I simply recommend the T1 as an integral part of a hi-end portable system, but comes with a hi-end price.

ACS T1 Custom-Fit IEM Summary
Title: ACS T1 Custom-Fit IEM Developer: Advanced Communications Solutions (ACS)
Reviewed Ver: T1 Version 2 Driver Type: triple balanced armature
Price: £649 (~ USD 1000$) Cable: Kevlar-reinforced
  • Best accessory package
  • Tiny, compact, and tough
  • Great cable, 3,5mm termination
  • Now customisable!
  • Excellent warm sound
  • Great extension and detail
  • Cable should be detachable

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