## Forums Search for: Octave

## What is "bandwidth" of Goertzel algorithm?

inLooking at Wikipedia article on Goertzel algorithm I thought I might be able to use it as a quick and dirty filter. I'm interested in looking...

Looking at Wikipedia article on Goertzel algorithm I thought I might be able to use it as a quick and dirty filter. I'm interested in looking at formants. Looking at the spectra of my specific test case, I'd want something from 10% of center to 1/3 octave but being> = 20db down an octave away.

## Questions regarding Octave

inOkay, so I need to make some plots that neither MathCAD nor excel can do easily, so I bit the bullet and installed Octave. After...

Okay, so I need to make some plots that neither MathCAD nor excel can do easily, so I bit the bullet and installed Octave. After wrestling with it for a couple of days I have to say I am, so far, extremely underwhelmed. I can't seem to find any succint help references. The online manual has a good bit of info, but it's not well organized IMHO, and not at all easy to wade through. In g...

## Patching Octave

inhi all, i am kind of new to software patching. i was looking for a fix for the "load .oct file" problem in octave 2.9.12 and...

hi all, i am kind of new to software patching. i was looking for a fix for the "load .oct file" problem in octave 2.9.12 and stumbled across the below patch. figured out that i had to do a diff -u -u "old file" "new file" but can somebody guide me through the process. thanks for the help in advance. maverick. ================================================ RCS fil...

## RFD: comp.soft-sys.octave

Dear all, Sorry for this multipost (for whose who have subscription to comp.soft-sys.matlab, news.announce.newgroups). This RFD had to...

Dear all, Sorry for this multipost (for whose who have subscription to comp.soft-sys.matlab, news.announce.newgroups). This RFD had to appear in this group as well but was some how missed. Please join the discussion for this new group for GNU Octave. REQUEST FOR DISCUSSION (RFD) unmoderated group comp.soft-sys.octave This is a formal Request For Discussion (...

## Reduced Interference Distribution for time/frequency analysis

inHi, I'm writing an audio application and for the most part I've been using an octave spaced decimating filter bank and applying FFTs to each...

Hi, I'm writing an audio application and for the most part I've been using an octave spaced decimating filter bank and applying FFTs to each octave. For my purposes this works pretty well (guitar processing) however I'm getting artefacts due to spectral smearing when I'm trying to resolve a low G and A - 98Hz and 110Hz - now obviously I could increase my FFT window size, but I really do...

## why first order filter have slope 6db/octave

inhi all i would like to know the technical description or derivation about the slope of a filter ie why we say that 1st order filters have a...

hi all i would like to know the technical description or derivation about the slope of a filter ie why we say that 1st order filters have a 20 dB/decade (or 6 dB/octave) slope. with regards rammya

## Fractional Octave Smoothing

inDoes anybody know a ref(s) to free description of fractional octave smoothing?

Does anybody know a ref(s) to free description of fractional octave smoothing?

## 1/3 Octave Analysis

inHi dears, Good Morning! I am new in signal processing and I am trying to do a work in noise control of an electronic steering lock device...

Hi dears, Good Morning! I am new in signal processing and I am trying to do a work in noise control of an electronic steering lock device (ESL). My aim is to calculate the loudness (Zwicker Method- ISO 532 B) of this device. To do so, first I need to obtain the 1/3 octave spectrum of a time signal that I measure with a microphone. The problem is I keep getting negative values in dB

## 3rd RFD: comp.soft-sys.octave (LAST CALL FOR COMMENTS)

REQUEST FOR DISCUSSION (RFD) unmoderated group comp.soft-sys.octave This is a formal Request For...

REQUEST FOR DISCUSSION (RFD) unmoderated group comp.soft-sys.octave This is a formal Request For Discussion (RFD) for the creation of the unmoderated Usenet newsgroup, comp.soft-sys.octave. PROCEDURE: The newsgroup creation process is currently undergoing revision. Please refer to the newsgroup creation policies listed here: http://w...

## Calc freqs of triple tuned bandpass filters?

inWhats the rule of thumb for how far to detune the two outside filters for third octave bandwidth? Is the middle filter supposed to have a little...

Whats the rule of thumb for how far to detune the two outside filters for third octave bandwidth? Is the middle filter supposed to have a little less gain to flatten the passband out? Is the Q of all 3 filters the same? Do the skirts roll off at 18dB per octave? (I searched for 'triple tuned' but no hits, so I hope I dont get flamed for asking)

## Octave and loading files via libsndfile

Hi all, As was discussed here late last week, I now have a new pre-release of libsndfile available here: ...

Hi all, As was discussed here late last week, I now have a new pre-release of libsndfile available here: http://www.mega-nerd.com/tmp/libsndfile-1.0.18pre15.tar.gz This version, if it detects the presence of the require files will also create binary loadable modules for GNU Octave which allows the reading and writing of sound files. It has been tested and is know wot work with G...

## Delay estimation code (Matlab / Octave)

Hello, some advertisement: I released a new version of my delay estimation subroutine (Matlab / Octave). It finds the delay and scaling...

Hello, some advertisement: I released a new version of my delay estimation subroutine (Matlab / Octave). It finds the delay and scaling factor between two cyclic (or zero-padded) signals, and applies it to one signal in order to match the other. Download links are on [1] at the top of the page. The main algorithm is described in my blog entry [2] from 2007, which was rewritten a month ag...

## Convert FFT to equal temper scale or octave

inI want to represent the audio spectrum of a signal. (I don't need to reproduce the signal, just represent it). The FFT gives linearly space bins,...

I want to represent the audio spectrum of a signal. (I don't need to reproduce the signal, just represent it). The FFT gives linearly space bins, but I want to represent it as a log scale. I've read posts about constant Q transforms and/or using filters to capture each octave. The first is a bit above me (I've gone from paper to implementation before and its tough), and the secon

## How to show biquad frequency response with logarithmic scales in Octave?

inHi, I'm new to Matlab/Octave and I need a simple frequency response plot. I googled freqz & plot, but it shows the frequency on linear scale,...

Hi, I'm new to Matlab/Octave and I need a simple frequency response plot. I googled freqz & plot, but it shows the frequency on linear scale, for audio, which is my case, it is much more suitable to watch logarithmic scale. How to do that? Thanks. jungledmnc

## FFT for Pitch Detection

inHi! Ive been recently using FFT for Pitch Detection and I notice that, although the notes are correct (e.g. C, D#, etc.), there are a lot of...

Hi! Ive been recently using FFT for Pitch Detection and I notice that, although the notes are correct (e.g. C, D#, etc.), there are a lot of notes that are in the wrong octave (e.g. E2 is categorized as E3, C3 is categorized as C4, always an octave up). Why is this the case? My algorithm is after calculating the FFT bins, I get the bin with the greatest intensity and calculate which frequenc...

## FFT wrong pitch octaves results

inIve been recently using FFT for Pitch Detection and I notice that, although the notes are correct (e.g. C, D#, etc.), there are a lot of notes...

Ive been recently using FFT for Pitch Detection and I notice that, although the notes are correct (e.g. C, D#, etc.), there are a lot of notes that are in the wrong octave (e.g. E2 is categorized as E3, C3 is categorized as C4, always an octave up). Why is this the case? My algorithm is after calculating the FFT bins, I get the bin with the greatest intensity and calculate which frequency it is...

## What does "6db per octave" mean in the digital world?

inHi, I had a hard time understanding the notion of "6dB per octave". If I have a single pole IIR low pass with the Fc = 1000 and Fs = 48000,...

Hi, I had a hard time understanding the notion of "6dB per octave". If I have a single pole IIR low pass with the Fc = 1000 and Fs = 48000, for example, a = [1.00000000000000 -0.87697646299276] b = 0.12302353700724 When doing freqz in Matlab, I was expecting -3db at 1000, -6dB at 2000, -9dB at 4000.... But what I have is -3@1000 -7@2000 -12.x@4000 -24.x@24000 Can anyone giv...

## 3rd Octave Biquad Filter Implemenation

inHello All I would like to use a DSP to implement a bank of filters for a real time audio analyzer. The filters are 1/3rd octave spanning from...

Hello All I would like to use a DSP to implement a bank of filters for a real time audio analyzer. The filters are 1/3rd octave spanning from 25Hz to 31K5Hz (32 filters). I was looking at using a C5505 to do the job, Can anyone point me in the right direction to get started on implementing biquad filter on this device? Or would I be better off using an FFT to do the job instead of biquads? ...

## help with my octave filter

inI use decimation filter plus IIR filters to do octave filters (20Hz-20kHz). Sample frequency is 48K. I found the filter shape distortion at...

I use decimation filter plus IIR filters to do octave filters (20Hz-20kHz). Sample frequency is 48K. I found the filter shape distortion at high frequency band (16k). I thought this might be related with the sample frequency, so I increase the sample frequency, but nothing is improved. what's wrong?

## Draw network

inHi to all, In Matlab it has its own software for drawing network or interconnection network. For give number of input port and...

Hi to all, In Matlab it has its own software for drawing network or interconnection network. For give number of input port and output port with given upper bound of relay count and probability of blocking how to draw a interconnection network using OCTAVE. Is there any tools for drawing the network or need to write programe for it and is there any example of Octave program for ...