An RTA shows relative sound energy level with bar displays.
Calibrating an equalizer in a stereo system properly requires the use of a real-time analyzer (RTA). Some RTAs are hand-held, some are free-standing and portable, some are rack-mounted, and some are computer software-based with appropriate analog interfaces and specially calibrated microphones. In home stereos, most RTAs are packaged in the system equalizer, complete with microphone and pink noise generator. This setup operates through the tape monitor loop. In cars, equalizers are in-line and have to be set up with a CD pink noise track and freestanding RTA and microphone.
Instructions
Car Equalizer Calibration
1. Set the calibration microphone up at ear level, using a microphone stand or clamp with a gooseneck adapter. Plug it into the RTA. If using a computer RTA, you can use the microphone mini-jack on the computer with any needed adapter to make it fit, or you can use a USB-to-analog input adapter.
2. Insert a calibration CD with a pink noise track into the head unit/player. Turn the volume to a level where most of the RTA display bars at and around 1000 Hertz are displaying at the zero dB point on the display screen.
3. Adjust the sliding controls on the equalizer down where the bars display above zero and up where the bars display below zero. When all or most of the bars' top edges display at zero, you have achieved "flat" frequency response, and you can turn off the pink noise and test the stereo with music.
Home Equalizer Calibration
4. Use the equalizer manufacturer's manual to connect it to the tape monitor loop of your preamp or integrated amp. Turn the preamp's balance control to one side. Plug in the calibration microphone and set it up one meter equidistant from the active loudspeaker's acoustic center, which is halfway between the top and bottom speaker drivers.
5. Press the tape monitor switch on the preamp and turn on the pink noise generator on the RTA portion of the equalizer. Set the volume to a level where most of the RTA display bars at and around 1000 Hertz are displaying at the zero dB point on the display screen.
6. Perform Step 3 in Section 1, except hold off on testing with music until you have repeated this procedure with the other speaker after you set the balance control to the other channel.
7. Turn off the pink noise generator and test the stereo with music.
Tags: pink noise, Equalizer Calibration, noise generator, pink noise generator, tape monitor
