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## How can a filter impulse response be interpolated?

inHi, I know how to interpolate a digital signal. It is first interpolated by inserting 0's. For example, one can add 4 0's to each data for a...

Hi, I know how to interpolate a digital signal. It is first interpolated by inserting 0's. For example, one can add 4 0's to each data for a 5 times interpolation. Then, a low pass filtering to eliminate the aliasing frequency. Now, I have a low pass filter from 0 to 10 MHz pass band with a sampling rate of 40 MSPS. I want to get the same 0 to 10 MHz response (it is not a flat pass band...

## 6dB/oct butterworth crossover doesn't have flat response

inHi folks, sorry if I'll be asking a dumb question :). I'd like to build a 6dB/oct crossover (with variable number of bands and crossover...

Hi folks, sorry if I'll be asking a dumb question :). I'd like to build a 6dB/oct crossover (with variable number of bands and crossover points). First order butterworth LP and HP filters seem to be working fine and provide nearly flat magnitude response IF the crossover point isn't high enough, hence close to the nyquist, then it starts forming something that looks like a high-shelf of +6dB. ...

## DSM integrator - how many bits?

inI'd like to implement a first-order delta-sigma power amplifier in Verilog. The input stream is N=16-bit wide (signed). How many bits should the...

I'd like to implement a first-order delta-sigma power amplifier in Verilog. The input stream is N=16-bit wide (signed). How many bits should the integrator have? Common sense says it would be enough for the worst-case delta (=N+1) + the actual content (also N+1), so N+2 bits. Is it correct? Can it be done with just N? Best regards, Piotr

## Kalman filter estimator for Gyro and accelerometer

inI am using a fairly standard approach to estimating angular pitch using a KF. It uses both accelerometer and Gyro angle data. Now it estimated the...

I am using a fairly standard approach to estimating angular pitch using a KF. It uses both accelerometer and Gyro angle data. Now it estimated the angle fine enough and I implement the steady-state KF. Never tried this before but then put a PID or lag-lead controller on this measurement. I find that the Kalman filter bandwidth is stuff all and severely reduces the bandwidth of my cl

## spectral accumulation using phase vocoder

inHi! I've made a simple freeze effect with a phase vocoder that can 'freeze' the sound by repeatedly converting the same spectral frame of that...

Hi! I've made a simple freeze effect with a phase vocoder that can 'freeze' the sound by repeatedly converting the same spectral frame of that sound to the time domain, incrementing the phases each time with the phase difference calculated from that frame and the previous frame. This works fine. What I would like to do though, is take another freeze frame out the incoming sound a

## Sensitivity function - control theory

inI watched this video about the sensitivity function, highly instructive, but at around 9 minutes, the author says that the maximum of the...

I watched this video about the sensitivity function, highly instructive, but at around 9 minutes, the author says that the maximum of the sensitivity function should be between 1.3 and 2. https://www.youtube.com/watch?v=BAWdZvF1O40 What's wrong with having a sensitivity less than 1.3 ? Regards

## Sine Wave autocorrelation, interpolation of phase

inHallo. For the purpose of measuring complex impedances i need to compare the phase of two copies of a sinewave over a number of periods. The...

Hallo. For the purpose of measuring complex impedances i need to compare the phase of two copies of a sinewave over a number of periods. The sinewave is generated in the same µC. Frequency is known and stable. The original and the shifted signals are sampled by a double synchr. ADC. The phase shift is the base for calculation of the complex Z of a load. I have implemented an (auto-)correlatio...

## Hah! Why 5-lug wheels balance

inQuite some time ago I handed y'all a quandary, to wit, proving that sum_{\theta} cos(\theta) = 0, when \theta is evenly distributed on a...

Quite some time ago I handed y'all a quandary, to wit, proving that sum_{\theta} cos(\theta) = 0, when \theta is evenly distributed on a circle and there are an odd number of them. (It's even if there's an even number of them -- you've got this nice pairing of cos(this) + cos(-this) = 0, and the proof is a few lines.) So, I ran across this page:

## polynomial fitting for COMPLEX data

inA package which calls itself "an industry-leading scientific graphing and data analysis software" suggests breaking the samples into real and...

A package which calls itself "an industry-leading scientific graphing and data analysis software" suggests breaking the samples into real and imaginary parts, and fitting curves to each. Hmmmph. I guess it is not a common task that they could be bothered coding. Now surely, one can just set up the Vandermonde matrix, where the elements are the sums of x, x squared, x cubed et cetera. Or wi...

## Unclipping

inI have lately become interested in the processing of audio signals recorded at too high a level, and so have clipping. First, I have a signal...

I have lately become interested in the processing of audio signals recorded at too high a level, and so have clipping. First, I have a signal that clipped at five samples (but only in one channel). The easy fix is to convert to a mono signal with the unclipped channel, but I might try to interpolate new values for the clipped samples. But I have another one that has about 17000 clipp...

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