Dolby Surround Pro Logic Decoder; Logic7 Decoder; Controls - AKG Acoustics HEARO 787 SURROUND Mode D'emploi

2 Description
2.6 Dolby Surround Pro Logic
Decoder

2.7 LOGIC7 Decoder

2.8 Controls

2.8.1 Headphones
Refer to figs. 1 and 12.
2.8.2 Transmitter
Front Panel
Refer to fig. 2.
12
sound waves (ear matching function). Thus, the various sound sources will seem to be located outside your
head even when you are using headphones.
LH FILTER
RH FILTER
The Dolby Surround Pro Logic decoder integrated in the transmitter uses a Dolby Surround encoded stereo input
signal to derive two additional signals, a center and a surround channel. The IVA circuitry generates from these
signals a binaural signal equivalent to reproduction through five high quality loudspeakers (three front, two rear
speakers). This allows you to enjoy all the benefits of Dolby surround sound even through headphones.
The integrated LOGIC7 decoder allows recordings in all audio formats (mono, stereo, Dolby Surround, and
LOGIC7) to be accurately reproduced through headphones. Depending on the momentary signal configura-
tion, two to eight loudspeakers are simulated at any time. Accordingly, the number of simulated speakers may
even change automatically during the same piece.
Also, the LOGIC7 decoder will derive a surround signal from a stereo input signal and is fully compatible to
Dolby Surround.
1. POWER: On/off button surrounded by an annular bicolor status LED (1a).
The status LED will light green to indicate the headphones are ON.
The status LED will light red while the batteries inside the headphones are being charged.
2. Charging contacts for charging the batteries on the transmitter.
2a Charging jack for the optional external charger.
3. Battery compartments (beneath the detachable left-hand ear pad): The battery compartments hold two
NiMH rechargeable batteries electrically isolated from the receiver circuitry by a protective foil. You cannot
charge the batteries before removing the protective foil.
4. AUTOTUNING switch: activates the automatic tuning function
5. VOLUME control
6. ON: Switches the transmitter on (switch illuminates green) and off (switch extinguishes).
7. DISPLAY: Switches the backlighting for all labels except the ON switch and the CHARGE label on and off.
If you switch the backlighting off, it will come back on automatically as soon as you push any front panel
switch.
If you switch the transmitter off and back on later, the backlighting will come on again, even if you switched
the backlighting off.
8. FREQ: Steps through three fixed carrier frequencies within the frequency band of your headphones sys-
tem.
The labels FREQ 1, FREQ 2, or FREQ 3 will illuminate to indicate the selected frequency.
9. MODE: Steps through normal stereo, IVA stereo, IVA plus Dolby Surround Pro Logic, and IVA plus LOGIC7
modes.
A: Natural hearing: Due to the effect of the head and pinnae, sound
waves arriving at one ear differ from those arriving at the other.
Amplitude and phase differences create a sense of spatial hearing.
B: Listening through headphones: Amplitude and phase differences are
eliminated. Sound sources are localized inside the head rather than in
the room.
C: Listening through headphones with IVA processing: The ear match-
ing function modifies the audio signals at the ears to resemble diagram
A. This restores natural, spatial hearing.
HEARO 787 SURROUND