Auto Calibration - NAD T747 Owner's Manual

OPERATION
USING THE T 747 – SETUP MENU

AUTO CALIBRATION

It has been shown that many, if not most, surround sound systems are not
accurately setup and calibrated. To be done properly, calibration requires
special knowledge and instrumentation that the average person probably
doesn't possess.
The Auto Calibration featured in T 747 uses a microphone, along with
sophisticated digital electronics built into your T 747, to automatically setup
and calibrate the T 747 to the exact speakers and speaker placement of
your own unique Home Theatre.
The following parameters are automatically measured and adjusted
accordingly.
• Noise Level : Check noise level relative to each speaker and subwoofer.
• Number of Speakers : Speaker configuration is detected including
number of surround speakers and whether a subwoofer and center
channel is connected.
• Speaker Distance : Accurately set the appropriate distance of
each speaker position as well as the subwoofer with respect to the
microphone position.
• Speaker Level and Size : T 747 crossover is set based on each
channel's signal handling capability and the subwoofer crossover
is automatically set. SPL (Sound Pressure Level) of each speaker is
matched with respect to the microphone position.
• Equalization : Adjust tonal quality (bass/treble level) for each speaker.
This applies to all sound fields and for each speaker.
This is a one-time set up, unless speakers are moved or changed, in which
case the calibration should be performed again.
4
MEASUREMENT IS THE FIRST STEP
Connect the microphone jack into the front panel's MP/MIC input. Place
the supplied microphone in the listening position at about the same
height as your listening ears. The microphone has a threaded insert at its
base that makes possible for it to be mounted on a tripod.
The sound at your main listening position is setup using the supplied
microphone. Depending upon the availability of speakers, you can
select either 7.1 or 5.1 setup. Upon selection of either 7.1 or 5.1, the auto
calibration starts – refer to the OSD as auto calibration steps through each
measurement parameter.
A special test tone is sent to each speaker and the data is memorized
by the T 747. The duration of setup may take some time depending on
the number of speakers. After the measurements, the T 747 calculates
the ideal system response for your particular room and speaker setup. If
some inconsistencies or discrepancies are detected during the setup, the
process maybe interrupted or the problem is shown in the particular setup
window. A notice screen is correspondingly displayed. After following and
undertaking the displayed instructions, re-start the Auto Calibration setup
again. When the measurements are finalized, the ideal system response is
calculated for your particular room and speaker setup.
NOTES
• Auto calibration is possible only for a 7.1 or 5.1 speaker configuration.
For other speaker configurations, like a 2.1 setup, you have to
manually set them up by referring to the guidelines below for Speaker
Configuration, Speaker Distance and Speaker Levels.
• The test tone emitted during measurement is loud. This maybe
bothersome for you and may affect as well your other household
members and even your neighbor.