4 Operating Notes
4.3.3 Dolby Surround
and Dolby Digital
4.4 Using
Loudspeakers
For connections refer to
section 3.2.1 and fig. 5
For base angle, see fig. 7.
4.4.1 Dolby Surround
and Dolby Digital
Refer to fig. 8.
4.5 Test Signals for
Choosing Ear Matching
Curves
Making the shortlist
22
1. Set the MODE selector (9) to "IVA-PHONES".
2. Set the SURROUND selector (7) to "AUTO".
The STEREO LED (8) will extinguish.
Dolby Surround Pro-Logic signals will automatically activate the Dolby Surround Pro-
Logic decoder and cause the PRO LOGIC LED to illuminate.
Dolby Digital signals will automatically activate the Dolby Digital decoder and cause the
DOLBY DIGITAL LED to illuminate instead of the PRO LOGIC LED.
The room simulations ("CLUB", "HALL", "STADIUM") are not available in this mode. (If
you set the SURROUND selector (7) to "CLUB", "HALL", or "STADIUM" even though a
Dolby Digital signal is present at the input, the output signal is automatically muted and
the INPUT LED (4) begins to flash red.
3. Select the ear curve that works best for you.
Begin by setting the EARS selector (10) to "N" for the standard ear curve. Try the other
six ear curves to find the one that you feel provides the most natural sonic perspective.
(You may find that you do not always prefer the same ear curve!)
4. Use the SOUND selector (11) to select the optimum sound setting.
Each of the four sound settings ("NORM", "MUSIC", "VOICE", AND "MOVIE") provides
three "subsettings" ("close", "medium", "wide") that let you change the spacing of the
loudspeakers simulated by IVA processing.
To increase the virtual distance ("stereo spread") between two closely spaced loudspeakers
(e.g., computer speakers, near-field monitors),
1. Set the MODE selector (9) to "VMAx".
The VMAx LED will illuminate.
2. Set the SURROUND selector (7) to "OFF" for straight stereo mode or to "CLUB", "HALL",
or "STADIUM" for stereo reproduction with room simulation.
The STEREO LED will illuminate.
3. Set the SOUND selector (11) to "close" (<10°), "medium" (approx. 20°), or "wide" (>30°)
depending on the base angle between your loudspeakers (A). The VMAx processor will
simulate for each of these settings a virtual loudspeaker pair (B) with a base angle of 60°.
Remember that in VMAx mode the SOUND selector (11) will only change the virtual
stereo spread without changing sound programs.
To enjoy the full effect of Dolby Surround Pro-Logic or Dolby Digital encoded videos or TV
programs through your existing stereo speaker pair,
1. Set the MODE selector (9) to "VMAx".
The VMAx LED will illuminate.
2. Set the SURROUND selector (7) to "AUTO".
The STEREO LED (8) will extinguish.
Dolby Surround Pro-Logic signals will automatically activate the Dolby Surround Pro-
Logic decoder and cause the PRO LOGIC LED to illuminate.
Dolby Digital signals will automatically activate the Dolby Digital decoder and cause the
DOLBY DIGITAL LED to illuminate instead of the PRO LOGIC LED.
The room simulations ("CLUB", "HALL", "STADIUM") are not available in this mode. (If
you set the SURROUND selector (7) to "CLUB", "HALL", or "STADIUM" even though a
Dolby Digital signal is present at the input, the output signal is automatically muted and
the INPUT LED (4) begins to flash red.
3. Use the SOUND selector (11) to set the spacing of the simulated loudspeakers. You have
a choice of three settings: "close", "medium", "wide".
Remember that in VMAx mode the SOUND selector (11) will only change the virtual
stereo spread without changing sound programs.
If you want to adjust your HEARO 999 AUDIOSPHERE to your hearing with extra precision,
visit http://www.akg-acoustics.com/english/headphones/Hearo999/ear-func.htm and down-
load two specific test signals in WAV or MP3 format. Use the first signal, "Applause", to make
a shortlist of the best ear matching curves. The second signal, "Acoustic Guitar Solo", is a
pure mono signal (same level in the left and right channels) for choosing the winner.
Of course, you may as well use applause and a mono signal rich in transients (such as a solo
piece for acoustic guitar) from an existing sound carrier.
1. Set the MODE selector (9) to "DIRECT".
2. Set the SOUND selector (11) to one of the three MUSIC positions.
3. Start the "Applause" test signal.
4. Set the MODE selector (9) to "IVA-PHONES" and the EARS selector (10) to "N". Set the
MODE selector (9) to "DIRECT" to compare the sound of the processed test signal with
the unprocessed test signal.