Tektronix WFM2200A, Руководство пользователя

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Elements of the surround
sound display
■ Level Indicators – indicate the audio level balance among the left (L), right
(R), left-surround (Ls), and right-surround (Rs) channels as cyan lines on the
Loudness Grid.
■ Loudness Grid – the ruled scale, radiating from the center, on which the level
indicators register their audio level and balance. The scale has tic marks at
10 dB intervals. An additional tic mark indicates the –18 dB level. The –
18 dB and –20 dB levels are typically used for aligning audio levels.
■ Total Volume Indicator – the cyan polygon formed by connecting the level
indicator end points, showing the total sound volume of the L, R, Ls, and Rs
channels. Each connecting line bends away from the center if the two signals
have a positive correlation, bends toward the center if the signals have a
negative correlation, and do not bend if the signals are uncorrelated.
■ Center Volume indicator – displays the sound volume of the center channel
as a vertical yellow bar between the L and R channels, and connects the ends
of the L, C, and R audio level indicators with straight lines.
■ Channel-Pair Phantom Sound Indicators (PSIs) – located on each side of the
Surround Sound display, indicates the location of potential phantom sound
sources formed by adjacent channels. The white tic marks on these moving
bar indicators show the phantom source locations. The bar length indicates
the correlation between the adjacent channels. A short-to-medium length
green bar indicates positive correlation between the channels, forming a
localized phantom sound source located at the white tic mark. The bar grows
to full length and changes color to yellow as the correlation moves to zero,
indicating a wide, non-localized sound image. The bar changes color to red
for adjacent channels with significant negative correlation. For negative
correlations, the ends of the PSI for the L and R channels continue to grow at
a 45° angle while the other PSIs remain at full length.
■ Center-Pairs Phantom Sound Indicator – a fifth PSI at the top of the display
shows potential phantom sources formed by the LC channel pair and the CR
channel pair. If the L, R, and C channels all have the same signal level, the
white tic mark on the bar appears directly above the C level indicator. The
white tic mark moves right or left depending on the relative balance between
the three channels. A short bar to the left of the white tic mark indicates a
positive correlation between L and C. The bar grows as the correlation
decreases. Like the L-R PSI, the bar continues to grow at a 45° angle for
negative signal correlations. The bar to the right of the white tic mark
behaves similarly, depending on the C-R correlation. This PSI indicator uses
the same color coding as the other PSI indicators.
Audio monitoring
228 WFM2300 and WFM2200A Waveform Monitors User Manual