2.Reset the test level: Return to the section “Setting the Subwoofer Test Level” on page 7. Perform the procedure as described.
3.Repeat the measurements: Now that you are familiar with the measurement process, you can go much faster by using Tracks
Your second measurement will no longer exhibit the deep response dip. However, the peak will still be evident. Without the influence of the response dip, the amplitude and center of the peak may have changed. Compare your new data to the examples given in this section of the manual. Follow the instructions for the example that most closely matches your new measurement.
Example 4. Narrow Response:
Figure 19. Narrow Response
Although it looks as though this system is quite
Apply the Width Selector as described above. Align the
14.Now adjust the Selector until you have achieved the “best fit.” The slider now points to the correct width setting. In this example, the frequency is 40Hz and the
Determine the appropriate level using the technique described earlier. In this example,
Skip to the “Adjusting the R.A.B.O.S. Equalizer”section on page 14.
Example 5. One or More Narrow Dips:
Figure 20. Example of two narrow dips
Response dips can occur at any frequency, sometimes immediately adjacent to the peak you want to correct. In this example, there are two such dips on either side of the peak. Deep response dips such as these are caused by destructive wave interference. Destructive interference dips occur only in one spot within the room. It is not uncommon to completely eliminate their effect by moving the RSLM to a different location. Note that this does not eliminate the dips. We have simply moved away from them. Sometimes only a few inches are required. Do not attempt to correct this condition with equalization. If you encounter dips like this, take the following steps:
1.Select a new test position: Cue the test track corresponding to the center frequency of the dip. In the example in Figure 20 you would play Tracks 14 (52Hz) and 18 (40Hz). Press Play ›. You will see a reading very close to what you had before. Now, slowly move the RSLM around the area, if possible remaining within about a foot of the original test point. As you move the RSLM, watch the bar graph. You will observe large level fluctuations. Find a location for the subwoofer or a test location that raises the response at these frequencies. You may find it helpful to move the RSLM vertically. Dips can be oriented in any axis. The position that restores the level to about that of the adjacent test points is your new test position.