Help
May i know what is the difference between FFT and RTA??? are they the same ????
1) What i found in sound check, both of them are seperated.
Spectrum analyzer
Real time analyzer
2) Meanwhile, FFT is inside the RTA for the REW
Could someone explain the difference？
May i know what is the difference between FFT and RTA??? are they the same ????
1) What i found in sound check, both of them are seperated.
Spectrum analyzer
Real time analyzer
2) Meanwhile, FFT is inside the RTA for the REW
Could someone explain the difference？
A spectrum analyser shows energy in logarithmicly spaced bands, typically third-octave at frequencies centered on 1kHz, 1.25 kHz, 1.6 kHz, 2 kHz, and so on, or rarely other spacings such as sixth-octave or half-octave.
An FFT decomposes a signal into evenly spaced component frequencies, spaced as sampling-frequency divided by the FFT length (usually a power of 2 because the math is easier that way), so for example running a 128-long FFT on a 48 kHz signal would show the amplitudes of 0 Hz, 375 Hz, 750 Hz, and so on.
Note once again that spectrum analysers work on logarithmic bands whereas FFTs work on evenly spaced frequencies. The spectrum analyser corresponds more closely to how the ear hears, while the FFT is good for analysing physical behaviours of objects.
An FFT decomposes a signal into evenly spaced component frequencies, spaced as sampling-frequency divided by the FFT length (usually a power of 2 because the math is easier that way), so for example running a 128-long FFT on a 48 kHz signal would show the amplitudes of 0 Hz, 375 Hz, 750 Hz, and so on.
Note once again that spectrum analysers work on logarithmic bands whereas FFTs work on evenly spaced frequencies. The spectrum analyser corresponds more closely to how the ear hears, while the FFT is good for analysing physical behaviours of objects.
Just to add to DSP__Geek’s reply and to directly answer your question: no, a FFT spectrum analyzer and a RTA are not the same.
One experiment that might help you visualize/understand the difference it is to take the FFT/spectrum of both white noise and pink noise - white noise will be flat and pink noise will have a downward tilt. Then take the RTA of both and you will see that pink noise is now flat and the white noise has an upward tilt.
John Murphy has a lot of info on RTAs here:
https://trueaudio.com/rta_faq1.htm
One experiment that might help you visualize/understand the difference it is to take the FFT/spectrum of both white noise and pink noise - white noise will be flat and pink noise will have a downward tilt. Then take the RTA of both and you will see that pink noise is now flat and the white noise has an upward tilt.
John Murphy has a lot of info on RTAs here:
https://trueaudio.com/rta_faq1.htm