# Tag Info

### Why is a linear phase important?

Let me add the following graphic to the great answers already given, with the intention of a specific and clear answer to the question posed. The other answers detail what linear phase is, this ...
• 51.4k
Accepted

### Why is a linear phase important?

A linear phase filter will preserve the waveshape of the signal or component of the input signal (to the extent that's possible, given that some frequencies will be changed in amplitude by the action ...
• 466

### Why is a linear phase important?

Just to add to what's already been said, you can see this intuitively by looking at the following sinusoid with monotonically increasing frequency. Shifting this signal to the right or left will ...
• 501
Accepted

### FIR Filter Design: Window vs Parks McClellan and Least Squares

I agree that the windowing filter design method is not one of the most important design methods anymore, and it might indeed be the case that it is overrepresented in traditional textbooks, probably ...
• 90k

• 4,285
Accepted

### Meaning of Phase response of a filter? In simple words?

There are many good answers here. I will try to take the reverse approach in order to explain in very simple words what is necessary in order to keep the output's shape same as input's, and what ...
• 2,611
Accepted

### How do software equalizers work?

This depends a lot on how you implement it. A single biquad takes about 10 arithmetic operations. (To be precise a Transposed Form II takes 4-5 multiplies and 3 adds, depending on how the gain ...
• 44.8k
Accepted

### What are the advantages and disadvantages of Kalman filter compared with FIR, IIR and low pass filter to filter data with noise?

Kalman filters really aren't that special, and you seem to be missing the point of a Kalman filter. A Kalman filter is really just a generally time-varying, generally IIR, generally multi-input ...
• 12.7k
Accepted

### High Dynamic Range FIR Filters

Like @MattL. and @aconcernedcitizen say, the issue is numerical. Python's scipy.signal.firls uses internally the solver ...
• 13.5k

### Half power frequencies is -6dB or -3dB

The definition of the cut-off frequency is arbitrary. Different design methods use different definitions. If you define the cut-off at $-6\textrm{ dB}$, it means that the amplitude of a sinusoidal ...
• 90k
Accepted

### Why the sum of filter coefficients of an FIR filter does not add to 1?

I'm assuming your FIR filters are nonrecursive tapped-delay line FIR filters. For such filters the sum of a filter's coefficients will equal the filter's gain at zero Hz (DC). This property results ...
• 5,817
Accepted

### Design a linear-phase FIR filter approximating the magnitude of a given IIR filter

What you do in step 1 is simply truncate the infinite impulse response to approximate it by an FIR filter. If you use sufficiently many filter taps, the approximation becomes arbitrarily accurate. ...
• 90k
Accepted

### What is the difference of windowing functions for FIR filtering?

So, from the discussion in the comments it's clear you know most you need to know. The window method for FIR filter design is based on this idea: We know the "ideal" frequency response $H(f)$ we ...
• 30.8k

### Mapping of Classic Filters for Digital Filter Design

I'm convinced that depending on the problem we're trying to solve, we can and should use both approaches: the transformation of classic analog filter designs, and the direct design in the digital ...
• 90k