Excellent sound

It was a pleasant surprise to listen to these for the first time. The sound is bright and clear, with just a suggestion of hiss at higher volumes. The headset is light and comfortable.

The headphones take two AAA batteries, either a proprietary rechargeable type (supplied) or standard dry cells. Charging is done in the supplied cradle/transmitter. Sony claims a battery life of 35 hours for alkaline batteries, and 20 for the rechargeables. The charger is smart and won't attempt to charge non-rechargeable batteries.

Note that the supplied batteries are nickel-metal-hydride, which deteriorates if not "exercised" (i.e. discharged fully) at least once every 3 months. The manual doesn't mention this.

Transmission is by infrared, which might seem limiting, but the headphones are designed to pick up the signal from any direction. You can turn your back to the transmitter and still pick up the sound perfectly. You can be anywhere in the room, as long as you are not actually behind the front edge of the transmitter.

Taking off the headphones turns the set off, so there's no need to worry about battery drain. This is accomplished by an ingenious inner "self-adjusting" headband that doubles as a switch.

Connection to your audio source can be either via a supplied optical cable, if you're lucky enough to have an optical out, or by standard left/right RCA jacks. You can use a miniplug-to-RCA stereo adapter plugged into the headphone jack of your receiver/amplifier, or a pair of RCA-to-RCA splitters plugged into any output such as the output of your CD player.

The transmitter can be set to "music" or "movie" for different effects, and it automatically adjusts for Pro Dolby or standard Dolby output. I can't comment on how this processing relates to 5.1 sources, since I live in a simple stereo world; but evidently there is at least the illusion of three-dimensionality through the use of the head-related transfer function (HRTF), a means of tricking the ear into thinking sounds are coming from different directions.