re: Nyquist limits of bandwidth

Hz) bands. By resampling to 60 Hz, which has a Nyquist frequency of 30 Hz, I can accurately capture these critical frequency ranges. Additionally, resampling reduces the data size and computational l

EMG in labs sometimes use higher sample rates, for example 500 Hz or 1000 Hz. However with Ganglion you are limited to 200 Hz sample rate. Technically by the Nyquist rule that would limit you to wavef

However, this configuration seems to exceed the Nyquist frequency of 100Hz for a 200Hz sampling rate, as 0.9765625Hz x 125 equals approximately 122Hz. Could you please provide insight into how the FF

If your signal is in the range of 100 to 126 Hz, then a 250 Hz sample rate is not going to do well at all. 'Technically' the Nyquist limit says a 250 Hz sample rate can record a 125 Hz signal, but tha

is quite good at picking up anything below its Nyquist frequency that is around. Probably if you go to an electronically 'quiet' area, like in the desert or uninhabited mountain area, you will get a

125 Hz EEG from the scalp, and samples at the Nyquist frequency (125 Hz) do not make any sense because of aliasing effects. You generally want 4 to 5 samples per waveform: 250/5 = 50 Hz max. If only

Hi! I've been experimenting with independent referencing with tests using 8 channels at fs of 250Hz. The first 6 channels are EEG, 7 is empty, and 8 is EMG. When I plotted the raw data in Matlab, I …

It depends on the sampling rate and follows https://en.wikipedia.org/wiki/Nyquist–Shannon_sampling_theorem

Josh (strikeroot) has suggested that due to the Nyquist theorem, he could achieve 125 Hz EEG with 250 Hz sample rate. That is not true and has been explained on previous forum posts here, search on N

You did not say which board. Cyton IS "DC coupled", but Ganglion is not. Top end is dependent on the sampling rate. Nyquist recommends two samples per waveform, but that is subject to aliasi

A disadvantage to down sampling at the rates you suggest, is that you will lose most of the higher brain wave frequencies. Due to the Nyquist limit. Practically, you want four or so samples per EEG wa

The Cyton sampling rate without Wifi Shield is 250 Hz. This gives a bandwidth according to Nyquist limit, of 0 to 125 Hz. But in actually, more like 0 to 50 Hz, since you want multiple samples per wav

Frequency is determined by the sample rate, according to the Nyquist limit. Typically you want about 4 or 5 samples per waveform. So 250 / 5 = ~ about 50 Hz max. Nyquist would say divide by two, 250 /

You have to get 2x the maximum frequency for the nyquist sample rate. I've done some pretty good stuff on processors with similar specifications.

Can you see that sample rates anywhere CLOSE TO the Nyquist limit are going to give extremely aliased and poor reproductions of the sampled signal? Look at some of the diagrams in that white paper. Su

re Nyquist 

re: Nyquist and aliasing. Do you understand the example I gave with the 50 hz samples of a 100 hz waveform? It will be hugely and badly distorted if sampled close to the zero crossings. The only way t

Nyquist limit gives terrible aliasing. Imagine say a 50 hz sine wave that we are sampling. If you are lucky to sample it at the + and - peaks (very lucky indeed), then your 100 hz sample rate gives yo

However if we are looking at 100sps we should get to roughly 45 Hz with Nyquist + 10%, which is the practical minimum iirc. What is your reasoning for 25Hz?