Re: spectrum analyser delay?

[Guest guest]

If you blink your eyes quickly and open them, of course you will see the activity in the power spectrum. The open and close are both producing electrical signals. Try tapping an electrode or gritting your teeth with your eyes open and see how much of a delay there is.

Try using 256 bins instead of 512 if you are really worried about this.Pete

Pete,

if I blink the eyes quicky and I open them, I can still see in the spectrum analyzer the low frequency starting to go up in amplitude and then down again.

It means that my blinking eyes artifact is shown on the spectrum analyzer with a couple of seconds delay.

Does it mean that my PC is slow to process the data? what's happen on your PC?

(In my opinion the delay is normal because it is due to the processing for making the FFT which is used to display the signal in the so called spectrum analyzer. 512 bins should delay the signal 512 samples. However, if on your PC you don't have delay then it means that there is a problem with my PC).

Please to be clear select which of the following statements is correct:

1) - on your PC there are no visible delay on S.A. (Ilario PC configuration has a problem)

2) - also on your PC (as on mine) the S.A. introduces delay which is normal due to the processing-- Van Deusenpvdtlc@...

http://www.brain-trainer.com305/433-3160The Learning Curve, Inc.

[Guest guest]

I don't use the spectrum analyzer as a feedback device.

Pete,By gritting the teeth I can see that indeed the delay depends on the number of bins.When number of bins is 128 response is quick, when bins are 1024 response is slow and delayed.

I would conclude that when we want to use the S.A. as real time feedback we must use few bins (to avoid delays), while if we want to use it to analize the signal after the session we can use more bins to have more frequency resolution. Do you confirm?

-- Van Deusenpvdtlc@...http://www.brain-trainer.com305/433-3160The Learning Curve, Inc.

[Guest guest]

I don't use the spectrum analyzer as a feedback device.

Pete,By gritting the teeth I can see that indeed the delay depends on the number of bins.When number of bins is 128 response is quick, when bins are 1024 response is slow and delayed.

I would conclude that when we want to use the S.A. as real time feedback we must use few bins (to avoid delays), while if we want to use it to analize the signal after the session we can use more bins to have more frequency resolution. Do you confirm?

-- Van Deusenpvdtlc@...http://www.brain-trainer.com305/433-3160The Learning Curve, Inc.