How can I test for rattles in a home theater?

Annoying rattles in a home theater prevent the viewer from fully escaping into the story line of the movie by serving as a reminder of their surroundings. Eliminating these with rattles rarely calls for more than a tube of silicon sealant or the installation of a few extra screws…once you find them.

To identify the array of rattles present in a home theater, you can run Sine wave sweeps with your Iasys HT. The following instructions can be found in Section 5, Page 5 of your Iasys HT manual.

  1. Connect the Iasys HT output to the amplifier powering the driver (or set of drivers) you want to test. If testing an electronic component, hook the output to the input of the device being tested.
  2. Place the microphone within the listening area and connect to Input 1 of the Iasys HT audio analyzer.
  3. For an electronic test, connect the output of the test device to Input 1 of the Iasys HT.
  4. Press the SWEEP button on the Iasys HT.
  5. Use Manual Select buttons on the Iasys HT or HT-100 signal router to choose the speaker you would like to analyze.
  6. Adjust the test level with the wheel while monitoring on the display screen the dBu of the signal output and the SPL of the input to Iasys HT. You are in the signal level adjustment mode when the line is underneath the dBu value on the middle right of the screen.
  7. To adjust the start and stop frequencies, use the OCTAVE SELECT buttons under the display screen at any time.
  8. To change the duration of the sweep, press the FREQUENCY button and then use the wheel while watching the display. The maximum and minimum possible sweep durations depend upon the bandwidth of the sweep selected.
  9. Press PAUSE to mute the signal and press PAUSE for the second time to resume at the previous signal level.

Sine Sweep with Iasys HT

Sweep slowly, at relatively high volume, until a rattle/buzz distortion is heard. Using the OCTAVE SELECT buttons successively narrow the range of the sweep to hone in on the frequency of the rattle. When down to an octave wide sweep, switch to the sine function to explore individual frequencies. Most likely, there will be rattles in screen covers, light fixtures, and the like.

Be cautious of speaker stress. A sweeping sine wave can be a stressful test of a speaker. You should take particular care with narrow frequency bands, high levels, and short duration when testing a speaker with a sweep sign wave.