Sony has obviously split its resources among infrared and RF based technologies on the wireless headphones matter. The product line includes four infrared based systems and four RF based systems. Sony wireless headphones can be identified by MDR indicative (e.g. Sony MDR-iF 140, Sony MDR-RF 920 etc.)
Also, Sony has perfected its wireless headphones that simulate surround sound, which are now really affordable. And by that you can tell that Sony is one of the titans. For instance, the MDR-DS 3000 is down to $200 from $400. You can buy additional sets for it, MDR-IF 3000.
Sony wireless headphones are:
- Sony MDR-IF140
- Sony MDR-IF240
- Sony MDR-IF540
- Sony MDR-IF630, for the infrared-based systems;
- Sony MDR-RF920RK
- Sony MDR-RF945RK
- Sony MDR-RF960RK
- Sony MDR-RF975RK, for the RF transmission technology.
Sony MDR-IF140 and others
When hearing about infrared devices you may want to wait a while before buying, but be sure with Sony's headphones you don't need to. Of course, with the infrared based systems, you cannot leave the room with your headphones on and still hear the music. The infrared signals cannot go through walls , furniture, or any other solid object. They just travel through air. If you were used to RF based transmissions, you'd better forget those and get used to harsher conditions.
But - and this "but" is great about IR systems - the infrared waves are reflected by solid surfaces, like walls for example. So, even if you are not in the same line with the transmitter, your headphones will still be able to receive reflected waves, and translate them into sound waves.
The reflected waves may give you weaker sound, it depends on the surface that reflected them. Usually, the thinner the walls, the better. If with MDR-IF140 headphones, the original IR wave can travel 8m (24 feet or so) from the transmitter, a reflected wave would travel only as far as 4m or 5m.
The real drawback here is not the range, but the sound quality: it is not near as good as the RF based systems. Many users complain about the hiss and the static that is quite dramatic. Of course, it depends on the environment, but you may not want to take that risk. Would it help that they are really cheap? The MDR-IF140 sets are available from $50.
Only the MDR-IF540RK system gets somewhere near perfect sound, though the range is still poor, up to 20 feet. These are a bit "expensive" though, up to $100.
Sony MDR-RF960RK and others
The RF based systems from Sony are not raising the kind of excitement we expected them, among users. Hiss and static are the most cited dissatisfactions.
Sony MDR-DS3000 and additional
Before MDR-DS3000, Sony was selling wireless headphones that simulated surround sound for $400. The newer MDR-DS3000 is now priced at a little more than $200.
The MDR-DS3000s use infrared technology, that Sony engineers are very fond of. But this means you won't be able to move too much to the sides from the transmitting line, because you'll lose some sound accuracy. In the box you'll find the headphones, the transmitter (base), an optical cable to connect to the DVD player or A/V receiver. The headphones are powered by a pair of NiMH batteries, also included.
Between uses, headphones recharge while upholding on the transmitter's cradle. They can also run on standard AAA alkaline batteries.
The sound is really surround, though a pretentious audiophile would complain about the hiss noticeable in the quiet scenes of a DVD movie.
If the family is big, the MDR-DS3000 system can be used with as many additional MDR-IF3000 sets (at $70 each) as you need.