The hottest Filters Substack posts right now

And their main takeaways
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Top Technology Topics

How to turn linear phase into truly linear phase

filterwizard • 0 implied HN points • 17 Sep 24
🕹 Technology Signal Processing Filters Digital Design Electronics
  1. FIR filters can have phase jumps that can affect signal quality. To fix this, one method is to use two filters in series, which cancels out unwanted phase jumps.
  2. Another approach involves tweaking the filter's impulse response to eliminate negative values in the Fourier transform. This ensures a smoother phase response without major changes to the filter's function.
  3. It's important to over-design the filter's stopband due to the adjustments made. This way, the overall performance remains reliable and avoids distortion in the filtered signals.

How linear-phase filters can still cause phase distortion

filterwizard • 0 implied HN points • 14 Sep 24
🕹 Technology Signal Processing Audio engineering Data Analysis Filters
  1. Even though linear-phase filters are supposed to keep the phase of signals the same, they can still cause unexpected phase changes. This can happen especially at stopband frequencies where the phase might jump abruptly.
  2. Using simple filters, like box-car filters, can lead to problems because they may not completely block unwanted frequencies. This can result in the output signal being inverted or misinterpreted, especially when analyzing important data trends.
  3. It's important to choose the right filter. Either use filters that effectively block unwanted frequencies or ones that don’t cause abrupt phase changes, to avoid messing up the signals you are trying to interpret.

Crossovers - an old paper, a new article

filterwizard • 0 implied HN points • 23 Aug 24
🕹 Technology Engineering Filters Industry News
  1. AudioXpress magazine has a lot of useful information about audio design, including preamps and crossover networks. It's worth checking out if you're into audio topics.
  2. There's ongoing research into improving crossover filters for speakers, especially using techniques like transmission zeroes. It's exciting to see how this could affect speaker design.
  3. Old research from over 40 years ago focused on creating analog filters with good phase response and power control. The goal was to make audio sound better overall.

Prediction and negative-delay filters: five things you should know

filterwizard • 0 implied HN points • 19 Aug 24
🕹 Technology Filters Signal Processing Data Analysis
  1. Filters can delay signals as they take time to process inputs and produce outputs. It's important to understand this delay, especially when working with different types of signals.
  2. While you can't completely eliminate delay in filters, you can create compensating filters to achieve zero or even negative group delay at certain frequencies. This can improve the accuracy of your system responses.
  3. Negative-delay filters can actually predict future values of a signal based on its current ramping behavior. This can be really useful in control systems and financial data analysis.
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