How To Measure Sound Intensity

Sound intensity, which is commonly referred to as the sound pressure level, is measure in decibels. Sound intensity refers to the sound power per unit area, which is usually measured in watts. Measuring the sound pressure level of speakers in your listening room will help you make better placement decisions to achieve the best sound possible. Therefore, here is a quick how-to guide that will show you how to measure the sound pressure level of your loud speakers.

What You Will Need

  • A sound pressure level (SPL) meter (Tip - Get a meter with a sensitivity range of at least 55 to 120db. You can order one online or buy one at your local Radio Shack store.)
  • Tripod
  • Sound test CD containing a pink noise track
  • Stereo system with loudspeakers
  • Paper and pencil

Step 1: Place Loudspeakers in Preferred Location

Choose a location for your loudspeakers. In the beginning, you don't need to worry too much about the starting point for your loudspeakers as you will probably be moving them often during the test. However, try to choose locations that allow your speakers to be placed equidistant from sidewalls. Also try to make sure that your listening position is centered between your loudspeakers.

Step 2: Set Up Sound Pressure Level Meter

Next, you need to set up the sound pressure level meter so that you can use it for testing. In order to set up your sound pressure level, you'll need to ensure that settings for weighting, response speed and base decibel measurement level are set properly on your meter. Generally speaking, choosing 'C' type weighting, slow response speed and a base measurement of about 80 dB is appropriate in most cases.

Step 3: Properly Place and Setup the SPL Meter and Tripod

When choosing a location for the sound pressure level meter and tripod, you should keep in mind where you will usually be sitting when listening to music or watching a movie. Try to position the sound level meter so that it is in the same location as your head would be during listening. You may need to move furniture around so that you can place the tripod and sound pressure level meter in the best location.

Step 4: Prepare Test Tone CD

Place the tone test tone CD in your CD player and make sure that your stereo is turned on.

Step 5: Start Making Measurements

Play that pink noise test track on the CD and adjust the volume of your stereo until the sound pressure level meter reads the 0 dB. This means that the sound pressure level at the meters location is actually 80 dB since that's the setting on the device. With each frequency, jot down the tone's frequency as relayed from the CD as well as the meter reading at that specific frequency. These measurements will reflect the frequency versus sound pressure level so that you can determine the best placement of speakers in your room.

Step 6: Adjust Loudspeaker Placement

Adjust the placement of your speakers as needed to try to maintain a 0 dB measurement on your meter. Make small adjustments in the placement of your loudspeakers and move them in small increments. For example, only move them 1 or 2 inches at a time. Then, repeat the test as many times as needed to get a constant 0 dB reading on your meter.

Popular P&S Cameras for High Quality Photos: