Real Time Analyzer (RTA)
RTA is divided into a number of separate bands in 1, 2/3rd, 1/3rd or 1/6th octave resolution. Each frequency band is graphed as a vertical bar on the RTA, the height of which represents the level—whether in dB SPL, dBu, etc.—of the individual octave or sub-octave bands. A 60dB range is displayed. If clipping occurs or the results aren’t visible, you can scroll up or down the display. Frequencies from 20Hz to 20kHz can be monitored individually. Measurements can be taken at four different response times and in four weighting types.
With input set to Mic, you can select the appropriate weighting and either 1-octave resolution (for a total of 10 bands on the RTA), 2/3-octave resolution (for a total of 15 bands), 1/3-octave resolution (for a total of 31 bands), or 1/6-octave resolution (for a total of 61 bands).
Electrical signal is measured by setting the input source to Line and measurement unit to dBu, dBV, or voltage, followed by response time, weighting, octave, peak hold, frequency detect, and Subtract/Sum properties. Signal is received through the PAA6’s female XLR jacks.
Also included within the RTA is an EQ setting function. Pushing the onscreen icon will allow you monitor the suggested equalizer band settings, which are updated in real time.
Compare Function (Subtract/Sum)
This function allows you to add the results from channel 1 to channel 2, or subtract either channel from the other (to compare the difference in level).
Fast Fourier Transform (FFT)
The FFT function in essence, is an RTA with much finer resolution and slightly slower refresh rate. Use the FFT analyzer to check the frequency response of sound systems and listening rooms as you adjust your speaker positions, room treatments and equalizer settings. A frequency range as wide as 0.2Hz to 20kHz can be monitored using the FFT function.
The RT60 function gives the decay time of any signal. The decay time is the time that it takes for a signal to diminish 60dB below the original sound. This can be done with no flat weighting or with A, B or C weighting. The RT60 calculations can also be made with no frequency filtering active (meaning the reverb time will be calculated for all frequencies, 20Hz to 20kHz) or with a 1-octave filter (the frequency of which can be selected from 10 preset values).
Total Harmonic Distortion Noise (THD N)
This function will give the total amount of distortion and noise in any given audio signal. The THD is the unwanted audio that is not directly a part of an audio signal, however still harmonically related to it.
The meter function can take calculations in dB SPL (through the built-in microphone), dBu, dBV, or voltage (through the line inputs). The SPL function shows the the overall ‘loudness’ of the input signal and can be accessed by simply selecting ‘Mic In’ as the desired input source. The dBu, dBV, and Voltage measurements are taken via the line inputs with visual representation of their respective levels.
The PAA6’s phase meter gives visual and numerical representation (in degrees) of the phase difference between the two input signals. Sine waves with the same frequency must be used, however the levels can differ. However, levels and frequencies must be stable to obtain consistent measurements.
This is an audio bandwidth oscilloscope. It provides an accurate graphic representation of audio waveforms, allowing you to identify distortion, clipping, and polarity problems.
Equivalent Continuous Noise Level (LEQ)
The LEQ is essentially a 10-band RTA that provides the linear average sound pressure levels over a pre-determined measure of time. The results of the LEQ can be taken for any period of time, from a few seconds up to a maximum of 48 hours. Results are updated on screen every second. This function is particularly useful for ensuring that noise standards are being met.