Performance

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.

Durability

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.