Rane THX Room EQ User Manual

Page 24

Home THX Equalization Manual Rev. 1.5

Chapter 7: Pink Noise, Circulating L-C-R-S,
-10 dB;

This signal is comprised of broad band noise

and can be used to calibrate all the individual
output level controls after the input level controls
have been calibrated. Set the level to read 75 dB
SPL on a sound level meter, C-weighted, Slow
mode in each channel in turn, measured from the
primary listening position.

Chapters 8-11: Pink Noise, Left, Center, Right,
Surround Channels, 0 dB;

This signal is comprised of broad band noise

and can be used to assist in aiming the Left,
Center, or Right speakers directly at the primary
listening area (especially in the vertical plane).
Simply listen for the best high frequency response
at your seated position. The Surround Channel
Test Signal (Chapter 11) may be used to test the
Surround Speaker positions for the best evenness
and envelopment of the Surround Field. When
played back through a correctly adjusted system,
these signals should yield 85 dB SPL on a sound
level meter, C-weighted, slow mode. These
signals can also used for spectrum analysis if
room equalization is performed.

Chapters 12-15: Frequency Sweep, 20 Hz to 20
kHz, Left, Center, Right, & Surround Channels,
0 dB;

This sine wave sweep covers the entire

audible range and can be used to measure the
frequency response of the Left, Center, Right, or
Surround channel electronics. Use in conjunction
with a chart recorder set for a 3 mm/sec. pen
speed. It is not recommended to use this test for
loudspeaker adjustments since room standing
waves make the results unreliable. Warning: this
signal can be damaging at high volumes. Care is
required in setting the volume for this test.

Chapter 16: Rattle Test, Frequency Sweep, 20
Hz to 500 Hz, 0 dB;

This is an extremely slow low frequency

sweep, intended to help pinpoint rattles, structural
resonances and other potential problems in the
bass. Warning: this signal can be damaging at
high volumes. Care is required in setting the
volume for this test.

Chapters 17-18: Slap Echo Test, Center and
Surround Channels;

This recording of a hand clap is repeated

several times to facilitate the identification of “slap
echoes” which might be stimulated by the system.
Slowly walk around the room, listening for a
fluttering, percussive echo following each initial
clap. Treat room surfaces accordingly. For best
results it is recommended to shut off the L, R, and
S speakers on the Center Channel Test, and the
L, C, and R speakers on the Surround Test.

Chapter 19-20: Video Test Patterns;

These patterns will enable a video technician

to correctly set you TV set, monitor, or video
projector to the correct levels of color, hue, con-
trast, and brightness.

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520-333 AUG95

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