We get to review a lot of headphones here at Tech2.0, but I try to bring in variations on the usual shootout theme. This time I’ve decided to pep things up by reviewing some wireless headphones that are sure to attract gamers and multimedia freaks – and at different price points. Koss, Sennheiser, and Philips sent us some of their products recently, so the initial selection wasn't hard to make.
Koss HB 79 – Rs 6100
This is a popular wireless model by Koss, and a nicely designed one at that. It’s black all over, with oval ear cups that engulf the ear fully. The right ear cup (or 'can') has a slot for two AAA batteries. This, however, can be a pain to open – the mild luster on the black surface is easily scratched. The rubber headband is flattish, and extends out to expose the shiny metal headband rib.
Overall the unit looks cool; especially thanks to small design details such as the way the ear cups are attached to headband, the positioning of the buttons etc. The ear cushions are made of foam with the regular creased covering, and the headphones sit very comfortably on your ears.
The speaker works on infrared (IR), so you have to position yourself in front of the transmitter, which is a rectangular, futuristic looking device. The Koss branding is conspicuous on the transmitter but not so much on the headphone – it's beveled out in the rubber covering off the headband, topside.
There's very little base noise disturbance, but it's not quite absent. If you keep the transmitter right in front, you can hit a nice sweet spot. Distance-wise it works fine till about 4.5m before noise kicks in. As for the sound, I like Koss drivers. They have a loud and tight enough sound to impress. The high mids, around 3-5K, are a little forward in this one (but only slightly).
For all the three headphones in this feature I listened to Chesky CDs to see how the high frequency sibilance is transmitted wirelessly – the highs are, after all, the main thing in wireless transmission. There are a few disappointments with the Koss, as it’s not pure and airy, though this is on very close scrutiny.
which is more sucessfull bleutooth device or infrared device pl. tell me 
