Infinity FIFTEEN manual Initial System-Level Setting, Setting the Subwoofer Test Level

Page 10

Initial System-Level Setting

The following steps will set the playback level of the system to the correct level for all tests that follow.

Turn the system volume to minimum.

Cue the R.A.B.O.S. Test CD to Track 2 and press Pause II. This track will produce band-limited pink noise in both the left and right channels.

Press Play ›. With the RSLM positioned as described above, increase the system volume until the RSLM display indicates –10dB. See Figure 4.

Figure 4. RSLM indicating the correct system level to begin tests (–10dB)

When you have completed this adjustment, press Pause II.

Setting the Subwoofer Test Level

Each of the following test tracks is about one minute long. This is normally much longer than required. Press Pause II or advance to the next test as soon as you are ready.

This step will set the subwoofer levels for measurement purposes. The objective is to scale the subwoofer’s output to make full use of the RSLM indicator range. Scaling is optimum when a 0dB reading is observed on the highest peak without triggering the over-range indication. Later, you will rebalance the subwoofer to the main speakers.

The three R.A.B.O.S. controls, ‚, ⁄ and B, should be set to fully clockwise positions, and all measurements should be conducted with their level controls in this position. Confirm this setting before you begin this test.The Level control ¢ should be set to the mid position.

Cue Track 3 and Pause II. Track 3 continuously steps through all subwoofer test tones for approximately one minute. Each tone will play just long enough for the RSLM to give a stable reading.

To get accurate measurements, it is necessary to play the subwoofer quite loud. The 0dB indication is about 94dB. At this level, frequencies below 100Hz can cause doors, windows, furnishings and other objects in the room to vibrate. This frequently results in clearly audible buzzes and/or rattles that come and go as each test tone plays. Strong buzzes not only sound bad; they can cause measurement errors. If you hear a buzz

or rattle during this test, it is highly recommended that you locate the source and eliminate its effects. This is actually a valuable room-diagnostic tool.

Press Play ›. As Track 3 plays, watch the RSLM carefully. Watch for peak readings. The peak reading may be no more than a brief flash. Readjust the subwoofer’s Level control ¢ until the peak level observed is 0dB without triggering the over-range indication. See Figure 5.

Figure 5. Adjusting the subwoofer levels for a 0dB peak

When finished, press Pause II.

Performing Low-Frequency Measurements

Read the following instructions fully before beginning tests.

For the following steps, you will need a Measurement Template and a pencil.

Figure 6. R.A.B.O.S. Measurement Template

7CASCADE MODEL FIFTEEN

Page 9 Page 11
Image 10
Page 9 Page 11
Contents Cascade Read First Upon completion of any service or repairsIi Cascade Model Fifteen Table of Contents Infinity Cascade Model Fifteen PlacementUnpacking the Subwoofer Controls and Connections Rear Panel ¡ £ ¢ ∞ §Set Normal/LFE Switch to Normal Set Normal/LFE Switch to LFEConnections Power On OperationRoom Adaptive Bass Optimization System R.A.B.O.S Contents of the R.A.B.O.S.Test CD Rslm PlacementTurn the system volume to minimum Initial System-Level SettingSetting the Subwoofer Test Level When you have completed this adjustment, press PauseLocating a test point Frequency What Does a Parametric Equalizer Do?Completing the Measurement Template WidthUsing the Width Selector Placement of the Width SelectorWhat You Measure, What to Do Skip to the Adjusting the R.A.B.O.S. Equalizersection onLevel Our example, you would enter 9 in the attenuation fieldExample 2. Two Response Peaks Example 3. Peak Adjacent to a DipExample 4. Narrow Response Example of two narrow dipsExample 6. Ideal Response Adjusting the R.A.B.O.S. EqualizerPosition Final System Balance Cascade Model Fifteen R.A.B.O.S. ControlsMaintenance and Service Frequency Frequency Specifications Cascade Model Fifteen
Related manuals
Manual 25 pages 20.38 Kb
Top Page Image Contents