Sony DP-IF5000 - Digital Surround Processor System Headphone with Power Supply
The brain of the system is the DP-IF5000, a digital surround processor that receives a digital (alas, only via the TosLink optical interface) or analog (regular stereo, two coaxial connectors) signal as input. This signal (the analog signal is pre-digitized by an 18-bit fifth-order converter with 64 times oversampling) is sent to a Dolby Digital/DTS decoder and then to a so-called Logic3D processor. Essentially, this is a 24-bit DSP from Motorola with a performance of 125 MIPS, which is entrusted with reverberation, echo and other transformations known to Sony alone, simulating the propagation of sound from six sources in the space of a room (the “Music” preset) or a cinema hall (the “Cinema” selection ", however, in my opinion, is preferable for any audio material). The MDR-DS5100 has two main effects, or modes, not counting traditional playback: “Virtual Front” and “Virtual Surround” (from any format). The first applies more to a regular stereo signal and takes the sound source out of your head into a virtual stereo system located in front of you. The second one expands any signal onto the entire plane surrounding you.
wireless headphones MDR-IF5000.

Their design has a number of remarkable features:
• an automatic power switch connected to the spring headband (that is, the power from two AA cells is turned on only if the headphones are worn on the head; by the way, the operating time from alkaline batteries or good batteries thanks to infrared transmission is at least 80 hours);
• four IR receivers (two front and rear) for reliable operation during any movement within a ten-meter range of the transmitter;
• own volume and balance controls;
• a special ring covered with soft fabric separates the emitter from the auricle so that it “hangs” over the ear in a certain position

The DP-IF5000 processor can simultaneously handle one more MDR-IF5000 headphone and one wired one, but! — the surround sound effect is achieved only in the MDR-IF5000 or wired MDR-F1 from Sony.
Main characteristics of the Sony MDR-DS5000 kit
Surround Sound Processor DP-IF5000
Dolby Digital decoder modes (two or six channels)Dolby Pro Logic
Sound processing modes without processing (“Off”, as in conventional headphones), virtual two-channel picture (“Virtual front”), virtual five-channel picture (“Virtual Surround”)
Carrier frequency of the IR transmitter, MHz 2.8 for the right channel 2.3 for the left channel
Transmitter range, m 10 (cone)
Transmitted audio frequency range, Hz 20–20000
Level of nonlinear distortion, % 1 (at a frequency of 1 kHz)
Wireless headphones MDR-IF5000
Reproducible frequency range, Hz 12–24000
Power supply: two AA cells
Weight, g 1000