Recent content by JonnyMcK

Yeah, that's what I was wanting originally. I have to say SomptingGuy's hilbert transform method worked a treat.....it saves the hassle of calculating the FFT, shifting the spectrum and then obtaining a new time-domain representation from this. Thanks anyway, Jonny

Okay. Thanks again! Jonny

That's perfect, thanks! Can I just ask how close is "too close" to the Nyquist frequency, and what sort of effects would I expect to see if there were some frequency components close to Nyquist? Cheers, Jonny

Hi, I am trying to shift the frequency spectrum of a signal by a fixed amount. A phase vocoder multiplies all frequencies by a fixed factor (for example, a factor of 2 moves 2Hz to 4Hz, 6Hz to 12Hz and so on) but I wish to move every frequency by a set amount (say, add 2Hz so that2Hz to 4Hz...

Thanks! I've just about cracked it. I'm not sure I explained myself as clearly as possible, perhaps because I was a bit confused about it myself, but you guys have been a big help. Thanks again!

<quote>Then using the voltage (NOT the power) you could linearly interpolate.</quote> I'm not sure exactly what exactly you mean by the voltage. I know how to measure the amplitudes of the frequency components of a signal, but not as a function of time. Would I be right in saying that by...

Hi again, I've been using the Hilbert function as suggested by Sompting guy. There's something that I'm not sure about though, and I wonder if any of you can explain it. If the instantaneous frequency is the time rate of change of the instantaneous phase angle of the Hilbert function, does...

Hi, I'm trying to sample the variation in frequency of an audio file using Matlab. Is it possible to break the audio file into a set number samples and construct an array containing the instantaneous frequency at each sample? Thanks!

Thanks!

Hi everyone. I am using Matlab to modulate a wave file using pulse position modulation (ppm) and I'm having a few problems. When I try to use a low carrier frequency I get an error message saying Matlab is out of memory. (It works if the carrier frequency is, say 10000Hz, the wave file sample...

I'd either like to frequency modulate it, or simply add the two signals together in a way that I can plot the result and record it to a .wav file. The main difficulty I'm having is reading the audio in a way that I can perform a simple addition of the two signals.

Hello everyone, I want to modulate a sample of audio with a square wave in Matlab. Any tips on how I could go about it? Thanks