Sleek-Audio has always been pushing the envelope when it comes to in-ear design, and now they have even made a clever way to remove one thing that has always been an issue with in-ears, namely the cable. The Sleek-Audio W1 Wireless Adapter comes as a kit with a transmitter and a receiver which allows you to use it with your current set of Sleek in-ears.
The installation is hassle free due to the fact that Sleek's in-ears all feature the same type of coaxial plugs on the monitor itself. The wireless system is made by a company called Kleer which enables lossless transmission of audio through a wireless connection, unlike Bluetooth which has a negative impact on the sound quality. The Kleer system used has a throughput of approximately 2.4 Mbps which is not a lot, but enough to get the job done.
The Sleek-Audio Wireless system can of course be used with both the original SA6 earphones and the recently launched Custom IEMs from Sleek. You can read those reviews here: Sleek-Audio SA6 Review
, Sleek-Audio Custom Earphones Review
- CD quality, lossless sound
- 10 hours of independent battery life
- 4 people can listen to one audio stream
- 60 feet of freedom
- Compatible with any device you can plug earphones into
The specification list for the W1 is somewhat short, however, it sums up the essence of the system. The lossless transfer of sound from the host device to the receiver is definitely one of the things that makes the Kleer based solution from Sleek interesting for audiophiles and people who enjoy a solid sound quality. During the course of my testing I averaged a bit over 10 hours of battery life which is nice. This may vary according to what volume you listen to. The 60 feet part is probably about right as long as you can see the unit. It will not push the signal through walls or anything like that.
"The claim of lossless sound is not 100% correct at least according to the manual, where it states that the sampling rate is only 16 kHz, since the sampling rate of a CD is 44100 Hz or 44.1 kHz.
" - It seems that there was an error in the Sleek-Audio manual, the sampling rate of the Kleer transmission system is indeed 44.1 kHz or CD quality equivalent. The current revision of the Sleek-Audio manual states 16 kHz, the right value is 44.1 kHz.
Some loss of sound quality is to be expected. Also the fact that it puts an ADC and a DAC in the signal chain will also most likely have a negative effect on the sound quality.
The Sleek-Audio Wireless system ships in a very colorful box.
In order to use the wireless kit you need a set of Sleek-Audio in-ears. The system can both be used with the SA6s and the new Custom in-ears since they feature the same connector. The Sleek-Audio W1 wireless adapter is definitely a nice upgrade path if you want to use the earphones for exercise or need better mobility.
The bundle is pretty neat, you get a carrying pouch which can fit the Sleek Wireless system and your DAP in if you are lucky. Besides that you also get a little mini-jack extender which allows you to use the system with old iPhones and other devices with recessed mini-jacks. In order to charge the transmitter and the receiver you get a dual-head micro USB cable.
The wireless transmitter and receiver look really good. They are made from black plastic with a gloss like finish (not scratch resistant). The receiver has two small rubber stress reliefs which also act as size adjusters. This is actually pretty nice because it allows you to raise the receiver from the upper part of your neck, to the lower part of your skull making it more comfortable to wear.
The wireless kit is extremely nice. Because you can remove the cable you have way less clutter and you do not have to wind up a long cable every time you have listened to some music. Using the W1 is a nice experience, after a relatively hassle free installation you get all the benefits of the device like less microphonic noise, the ability to have your device quite a bit of way from the receiver and a more practical solution.
The receiver has the same on / off button as the transmitter and uses the same micro USB port for charging. One full charge should give you about 10 hours of listening time. If that is not enough for you, you can always take the cable with you. The earphones are incredibly easy to detach from the wireless system and hook up to a cable.
On the receiver there are two relatively large rubber stress reliefs which double as size adjusters.
The transmitter is quite small and has a standard mini jack connector on it. You can hook it up to pretty much any DAP with a 1/8" jack, but if it is recessed you need to use the extender cable that Sleek also includes with this product (old iPhone, some obscure PMPs and DAPs).
The Sleek-Audio W1 looks as though it was made for the Cowon D2. The D2 is a little thicker than the W1 transmitter but overall the fit is great, definitely a very pocket friendly solution.
Sleek's cable and connector assembly looks just like that of the original cabled solution.
When you have established a connection between the receiver and transmitter they both blink once every few seconds. If they cannot connect they blink a lot faster. The indication system works nicely, you are never left in doubt as to why the unit is not playing.
Above you can see the Sleek-Audio W1 hooked up to a set of custom Sleeks and a Cowon D2.
Judging the performance of this system is rather tricky because there are a lot of environmental variables, such as interference from other wireless units and EMI noise from other devices. I tried my best to eliminate most of these variables by using them in different places with and without wireless units near me.
I found that the Sleek-Audio W1 system, which is based on Kleer wireless technology, has almost the same performance no matter what type of noise surrounds you. The only thing that is critical is if you are using the extender cable and that crosses a cable. That made for some spectacular noise. The Kleer technology claims to be lossless, but it is not. It is not a night and day difference but the loss of clarity is noticeable to the keen listener on some tracks with complex passages. In a normal usage scenario it is not the loss of fidelity that annoys me it is the background hum. The Kleer systems adds an "E"-type noise which is quite unpleasant to listen to in the long run, the only relief is that it is constant no matter what volume to listen to. So that if you turn up the volume you can "drown" it. This, however, defies the purpose of in-ears which is lover preferred listening level compared to traditional headphones in noisy environments.
What I really dig about the wireless kit is that it eliminates the majority of microphonic noise, making it ideal for use on the move or when you are working out. The added freedom of the wireless system is a nice change and is a real pro. The ability to walk around your room without having to worry about cables or lugging around a PMP is such a relief. The reach of the wireless system is more than enough to cover my 30 square meter room and it will even extend into the pathway to my room. If you can see the base unit you should be fine, the more stuff is in the way the lower the range. From my experience with Bluetooth headsets I would say the Kleer system offers the same range, and gives you a lot better sound quality for the money.
At $120 the Sleek-Audio W1 wireless solution is pretty unique and will most likely please a wide crowd for the time being. I think there is still lots of room for improvement, my main beef with the system is the "E"-hum and slight hit to the sound quality. Otherwise I feel as though this product is worth the bucks spent on it, it delivers what it is supposed to, but not much more than that. In order to try and fix the "E"-noise I tried switching the channel which is done by holding both connection buttons down for a few seconds and then letting them mate again. I tried loads of channels, but did not manage to fix the "E"-buzz.
Another noticeable effect of having the wireless adapter in the signal chain is that it adds a bit of bass. The midrange is left relatively unchanged, but it does not sound quite as smooth or liquid as before.
During my tests I was averaging about 13 hours per full charge which is 3 hours more than Sleek states! This is of course depending on your listening level, and given I was at home without a lot of background noise, but it is still remarkable that it outdoes its specifications in a close to ideal environment.
Both the receiver and transmitter have a relatively durable hard plastic casing, but I would not count on it to withstand serious abuse. Like any other in-ear accessory these are just as vulnerable as the IEMs themselves. The unit does eliminate most of the cable problems because there is no cable going from your PMP to the earphones.
Value and Conclusion
- The Sleek-Audio W1 Wireless system cost $120.
- Wireless duh!
- Reasonably good sound quality
- Alright build quality
- Easy to use
- Works with existing Sleek-Audio in-ears
- Adds some bass
- Removes 99% of microphonic noise issues
- Still not completely cable free
- Not 100% lossless
- Works only with Sleek Audio products
This type of technology represents a major leap forward for the in-ear users because it eliminates most problems associated with cables, such as durability and microphonic noise. It is a lovely piece of kit, but it still remains clear that the Kleer technology has some major deficits, especially when it comes to the background hum or noise if you will. With a noticeable "E"-buzz going on, listening fatigue is much higher when using the W1 compared to just running them of my DAP or amp plus DAP combo. The sound quality takes a small hit, but it is barely noticeable unless you are sitting and listening intensely to the music.
The rest of the benefits are pretty obvious. Free from cables you are able to roam around your room without having to take your PMP or DAP with you all the time. Besides that not having a cable to pass through your jacket when going outside makes IEMs much less of a hassle to use on a daily basis. Even though it is not a perfect solution it is still more than good enough to warrant its existence, but do not expect it to be on par sound wise with a cabled solution. The great part about the Sleek-Audio version is that it can be used with all of the earphones Sleek produce.