Comments on Profile Post by frenchbat

  1. purr1n
  2. frenchbat
    frenchbat
    Yeah I saw that thread a while ago. However I liked the practical examples in that blog post.
    Aug 1, 2018
  3. purr1n
    purr1n
    In the case of DACs, different use case: low pass filters instead of high pass. Practical examples are easy with DACs that offer selectable filters. Can also use Audirvana playback with own upsampling and filters to test things out.
    Aug 1, 2018
    monacelli likes this.
  4. frenchbat
    frenchbat
    I wouldn't trust a blanket statement on filter for all dacs. To these ears and on this dac here, minimum phase doesn't sound like shit. For others, all bets are off.
    Aug 1, 2018
  5. purr1n
    purr1n
    I'm finding it's more DAC / system dependent.
    Aug 1, 2018
  6. Serious
    Serious
    I think minimum phase makes a lot of sense for EQ filters. When correcting a speaker/headphone FR you're essentially correcting both the phase and magnitude response at the same time.
    Aug 1, 2018
  7. ultrabike
    ultrabike
    That article AFAIK is total bullshit. And no, minimum phase filters make no sense for EQ. The only reason one uses a minimum phase filters is to have as little latency and as little latency as possible. Otherwise they are total shit. I'm not just talking. I've been there and I know EE PhD's have been burned by this.
    Aug 1, 2018
    monacelli and Serious like this.
  8. ultrabike
    ultrabike
    As far as practical examples is concerned I have process shit loads of signals with both linear phase and minimum phase filters. I think I even uploaded some examples here and/or in Changstar. I don't know what else to do. That's as fucking practical as one gets.
    Aug 1, 2018
    Serious likes this.
  9. Serious
    Serious
    @ultrabike Gonna have to test it again to see what sounds best
    Aug 1, 2018
  10. ultrabike
    ultrabike
    I'm all for that. Which one sounds better is not the problem. That's completely a personal choice. But those guys are talking about phase shifts in the frequency content. And the technical claims are all fouled up. In terms of reconstruction a linear phase filter will always destroy the equivalent minimum phase. Always.
    Aug 1, 2018
    monacelli likes this.
  11. ultrabike
    ultrabike
    There are always going to be phase shifts once the signal goes through a filter. It's just that with a linear phase filter all frequency content adds up coherently and with the right "padding". It only results in latency. This is probably not obvious to most folks. But is very basic for DSP engineers.
    Aug 1, 2018
  12. ultrabike
    ultrabike
    You get it right @Serious? You are an EE or on your way to become one right?
    Aug 1, 2018
  13. Serious
    Serious
    But what about when we want to EQ a bump in the frequency response of a headphone with parametric EQ? We want to fix both the bump and the phase error that comes with it.
    Anyway, gonna test that now.
    Aug 1, 2018
  14. Serious
    Serious
    Then again once you use FIR filters anyway you can correct the phase response, too. I'm talking about "simple" parametric EQ filters, but there's really no point to limit yourself to that. Plus you can fix phase errors from speaker crossovers, etc.
    Aug 1, 2018
  15. ultrabike
    ultrabike
    A PEQ is a set of cascaded bi-quad IIRs. There is no way in hell those are going to be linear phase. A FIR is superior when it comes to phase. But they tend to be much larger for similar specifications.
    Aug 1, 2018
  16. Serious
    Serious
    No, what I mean is do we even want linear phase in that case?
    Aug 1, 2018
  17. ultrabike
    ultrabike
    This is moving away from DAC filters and into EQ. But as far as that you don't necessarily care about the EQ by itself. You want the overall response to be linear phase.
    Aug 1, 2018
    Serious likes this.
  18. frenchbat
    frenchbat
    Damn, I should have wrote provoking thought, instead of food for thought.
    Aug 1, 2018
    ultrabike likes this.
  19. ultrabike
    ultrabike
    My wife lost her plane to. I was in a very bad mood.
    Aug 1, 2018
    frenchbat likes this.
  20. frenchbat
    frenchbat
    Seems like you needed to vent. Glad I offered the opportunity.
    Aug 2, 2018
    ultrabike likes this.