Speaker Levels - NAD T755 Owner's Manual

OPERATION
USING THE T 755 –SETUP MENU

ENHANCED BASS
When the subwoofer is set to ON and one or more speakers are set to "Large", Enhanced Bass is also
available. Normally, with speakers set to "Large" the subwoofer is not active. The Enhanced Bass option
allows full range operation of the speakers with the additional bass contribution of the subwoofer. This
feature is particularly useful when one wants to experience maximum bass output. Please note that
due to acoustic cancellation effects, the bass response may be uneven when using this setting.
You can set Subwoofer to "On" even with "Large" front speakers, in which case bass content from any
channels set to "Small" will be routed to both the subwoofer and to the front speakers; LFE-channel
signal will pass only to the sub. In most subwoofer-equipped systems, setting front speakers to "Small"
is usually the better option.
All the speakers' low frequency content can be directly adjusted within the range 40Hz to 200Hz.
NOTE
The configurations set forth at "Speaker Setup" are carried over whenever it is enabled during A/V
Preset setting. Please see also the section "A/V PRESETS" for reference.

SPEAKER LEVELS

Adjusting the relative balance of your system's loudspeakers ensures that surround-sound recordings,
whether music or film, will present the balance of effects, music, and dialog that the artists intended.
Additionally, if your system incorporates a subwoofer it establishes a correct relationship between the
volume of the subwoofer and the other speakers, and thus of low-frequencies (bass) to other sonic
elements.
USING AN SPL METER
It is quite practical to perform the T 755 level setup routines "by ear", and careful work will produce
acceptably accurate results. However, the use of an inexpensive sound-pressure level (SPL) meter,
such as Radio Shack part number 33-2050, makes this task easier, more accurate and more repeatable.
Ownership of such a meter could prove a valuable audio tool. Your NAD audio specialist may be able
to help you with temporary use of a meter.
The SPL meter should be placed at the primary listening position, at approximately the height of
the seated listener's head. A tripod is helpful but with a little duct tape almost anything — a pole
lamp, music-stand, or ladder-backed chair, for example — can do as well. Just be sure that no large
acoustically reflective surfaces obstruct or are near the microphone element.
Orient the meter with its microphone (usually at one end) pointing straight up toward the ceiling (not
toward the speakers) and ensure that "C" weighting scale is selected. Set the meter to display 75 dB
SPL. On Radio Shack meters, this necessitates either setting the meter to its 80 dB range and taking
your readings at the -5 point or selecting the 70 dB range and reading at the +5 point.
SETTING SPEAKER LEVELS AT TEST MODE
While at "Speaker Levels" menu, press the HTR 3 remote's "Test" key activating the T 755's Speaker Levels
balancing test signal. You will hear a "surf" sound as you step through your speakers ("test" appears to
the right side of the current speaker), beginning with the Front Left. If you do not hear the test signal,
check your speaker connections or your "Speaker setup" menu settings.
Use the remote's [ ] keys to adjust the loudness of the noise output from the currently playing
channel to the required level (it's usually simplest to begin with the Front Left). As you cycle the test
signal around the speakers, the OSD will highlight the currently playing channel. The "level offset"
reading on the right will change by 1 dB increments; ±12 dB adjustment is available. Press [ENTER] to
adjust the next speaker.
NOTE
If you are balancing levels "by ear", choose one speaker—usually the center— as a reference and
adjust each of the others in turn to "sound as loud" as the reference. Be sure that you remain in the
primary listening position while balancing all channels.