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TSS-SUB4000
The pointer on the slider will indicate the correct width setting.
Enter this number in the Width field of the Measurement Tem-
plate. In our example, the width is 12.5%.
It is not realistic to expect a perfect fit. Acoustic mea-
surements encompass the behavior of not only the speakers but
of the room and its contents as well. Reflected energy, standing
waves and ambient noise all add their part. Determining the
best width setting nearly always requires compromise.
Level
This setting will define the amount (level) you want to reduce
the peak, in decibels.
The R.A.B.O.S. level adjustment is limited to attenuation only,
and is adjustable from 0dB to –14dB. After optimization, the
R.A.B.O.S. equalizer will eliminate the largest low-frequency
peak; therefore, the broadband bass level can be increased
without overpowering the midrange frequencies. R.A.B.O.S.
applies this compensation automatically.
You will use the Width Selector as an aid in determining the
correct level setting. Place the Width Selector as described
above and adjust it to the correct width. Observe the first fre-
quency point on the high-frequency side of the peak that no
longer follows the slope of the Width Selector. In this example
this is 56Hz. Calculate the average level of the readings from
56Hz up to 100Hz; that is, 10 data points in this example.
Whenever your answer has a remainder, always round down
(disregarding the negative [–]) to the next whole number.
In our example, you would enter 9 in the attenuation field.
This may not be the best method in all cases.The next section
contains several other examples.
What You Measure,What to Do
As stated earlier, it is not possible to anticipate the effect of
every possible listening environment. However, most residential
sound rooms share many characteristics, and their dimensions
fall into a range that make some response irregularities far
more likely than others. On the following pages are examples of
what you may encounter. Following each example is a strategy
for correction. Compare your measurement results with the fol-
lowing examples. Find the one that best fits your graph and fol-
low the instructions presented for that scenario.
Remember, when looking for a match, look at the
descriptive characteristics, not any specific frequency or level.
Each of these examples can occur at any frequency, bandwidth
and level. It is unlikely that your test results will be exactly as
depicted in these examples.
Example 1.
Single Dominant Peak:
Figure 16. Single dominant peak
This is the most common result of speaker/room interaction.
Apply the Width Selector as described in Figure 14. Align the
center line of the Selector over the center of the peak, as
shown in Figure 15. Now adjust the Selector until you have
achieved the “best fit.”The slider now points to the correct
bandwidth setting. In this example, the frequency is 43Hz and
the best-fit width is 12.5%. Fill in the Width and Frequency
fields provided on the template.
Determine the appropriate level using the technique described
earlier. In this example, –9dB would be best. Enter the level in
the field provided.
Skip to the “Adjusting the R.A.B.O.S. Equalizer”section on
page 14.
56Hz
63Hz 66Hz
72Hz 77Hz
80Hz
85Hz
90Hz
95Hz 100Hz
–9
–10
–8
–9
–10
–9
–8
–10
–10
–9
–
92
÷
10 =
–9.2
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