## circular convolution again

Started by in Audio Signal Processing17 years ago 4 replies

Hello! I have some more comments... Akash's points on the comparison between FFT and convolution are indeed agreeable. But I guess the...

Hello! I have some more comments... Akash's points on the comparison between FFT and convolution are indeed agreeable. But I guess the original query by John was abt the use of 'circular' convolution and not linear convolution. Now, if u are going to use convolution for ur application, it will always be linear convolution, isn't it? u can go for circular convolution as well, but then u need

## circular convolution

Started by in Audio Signal Processing17 years ago 11 replies

Hello friends, I have trouble in understand the concept and the application of circular convolution. Wonder if someone can help me out a bit...

Hello friends, I have trouble in understand the concept and the application of circular convolution. Wonder if someone can help me out a bit please! I came across this statement from a text "... circular convolution of 2 sequences is found by performing the linear convolution and aliasing the result...." In eqn format, the text defined circular convolution as y(n)=[summation(k

## Circular Convolution

Started by in Audio Signal Processing15 years ago 1 reply

Greetings, I was wondering if there was a way to perform convolution without lengthening the signal. Can cirular convolution be used for...

Greetings, I was wondering if there was a way to perform convolution without lengthening the signal. Can cirular convolution be used for this? Everything I've looked up so far only mentions graphics operations. I am working with sound.

## Frequency Domain Convolution

Started by in Audio Signal Processing11 years ago 3 replies

Hi all this is my first post, I was looking for some help with frequnecy domain convolution. > From what I understand multiplication in the...

Hi all this is my first post, I was looking for some help with frequnecy domain convolution. > From what I understand multiplication in the time domain is equivalent to convolution in the frequency domain and vice versa. What I would like to do is produce the same frequency spectrum produced by hann windowed audio (in the time domain), which is done through time domain multiplication, b

## Question about cross-spectrum and convolution

Started by in Audio Signal Processing14 years ago 1 reply

Hi, I have a question regarding the concept of cross-spectrum, which is defined as the Fourier transform of convolution between two signals X and...

Hi, I have a question regarding the concept of cross-spectrum, which is defined as the Fourier transform of convolution between two signals X and Y: FT(X*Y) Isn't it the same as: FT(X) FT(Y) My simple clue is: X*Y = IFT( FT(X) FT(Y) ) So, FT(X*Y) = FT(X) FT(Y). Am I right? Thanks

## Re: Digest Number 442

Started by in Audio Signal Processing13 years ago

Hi PrzeM, Yes, it is very possible to calculate the window-modified spectrum, which is a convolution of the data spectrum and the window...

Hi PrzeM, Yes, it is very possible to calculate the window-modified spectrum, which is a convolution of the data spectrum and the window spectrum. However, the temporal windows were invented to save efforts, instead of performing convolution in the freq domain perform multiplication in the time domain. Regards, Andrew > 2. Hann windowed FFT from 'rectangular' one ? > Posted b

## DSP development platfrom

Started by in Audio Signal Processing11 years ago 3 replies

Hi All, I have tried to post a few times, so if this message is redundant, please ignore. I'm a E.E. in senior design, and I have an...

Hi All, I have tried to post a few times, so if this message is redundant, please ignore. I'm a E.E. in senior design, and I have an idea for a project that will involve extremely fast convolution of audio signals. I have found a few methods that I believe will work, and I am interested in hearing your opinion on what flavor of DSP or FPGA would be suitable for this task. Basic...

## DFT-based Filtering: does it matter if I normalize by N in the FFT or iFFT?

Started by in Audio Signal Processing14 years ago

Hi all, and apologies in advance for the long-winded question. I have recently implemented a fast convolution algorithm using the FFT/iFFT to...

Hi all, and apologies in advance for the long-winded question. I have recently implemented a fast convolution algorithm using the FFT/iFFT to convert input signal and filter into the frequency domain, multiply them out, and iFFT them back to the time domain to get my result. It all seems to work fine, however, I recently got a little confused on one point. I need to determine the gain th