Absolute polarity test

Discussion in 'Audio Science' started by MLegend, Oct 14, 2020.

  1. Kouon

    Kouon Rando

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    Fair point. That was the conclusion I’ve been reading here and elsewhere too (phase getting mangled a lot during recording, or one instrument/track being in opposite phase to the other). I do still want to maintain absolute phase though for the few albums that do maintain it properly, however. Those that don’t will probably just sound just that tiny bit different from before.

    I’m probably coming more at it from a more me-being-OCD-about-stuff standpoint though.

    Maybe what I’m trying to say is, give it a shot especially if you know your amp is polarity inverting. Worst case you can just toggle it back off. The CTH is just as good an amp despite the phase flip though, but I just never thought it would be this noticeable.
     
  2. ergopower

    ergopower Friend

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    I didn't phrase my observation very well. When I said reflection, what I meant was that the Raw file sounded like a dude speaking in a 9 - 10' wide studio or room, the reflection or echo of his voice sounds like the walls are about half that distance from his head. The Inverse file, there was some echo or reflection, he's not outdoors nor in an anechoic chamber, but I couldn't get a fix on how big the room was. I didn't notice fan or other noise.
     
  3. MLegend

    MLegend Friend

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    Since inverting the signal in post-production doesn't solve this issue in my setup for live scenarios, which is what I use it for, I needed to fix this on the hardware side. I thought it was the cable, so I ordered a new one and the new cable sent a reversed polarity signal from the output on my DBX 286s to my interface as well. This made me think the DBX was the issue.

    I decided to buy the Galaxy Audio Cricket polarity tester to check the cables and lo and behold the cables were wired correctly. I desoldered the cable, switched the wires and this fixed the issue. The DBX was the issue.

    So if you're curious about polarity in your setup, the Galaxy Audio Cricket is a pretty neat and useful tool to check and test your equipment.
     
  4. Tom R

    Tom R Rando

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    I use the polarity switch on my DAC a Iot. I find that it is most noticeable with instruments that have very asymmetrical timbres - like trumpets. Very obvious which way is correct. I wish my preamp had a phase invert switch so I could check on my analog sources.
     
  5. yotacowboy

    yotacowboy McRibs Kind of Guy

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    Does anyone know if there's any push for Roon to allow for polarity settings to be captured in a track's metadata?
     
  6. purr1n

    purr1n Burned out

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  7. Thad E Ginathom

    Thad E Ginathom Friend

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    Audiocheck is a wonderful site, for checking everything from one's ears, one's gear, to the entire universe!

    Best not to go there without at least a couple of hours to spare. Every test on their menu makes one wonder if (or how much) one can!

    Enjoy :)
     
  8. Beefy

    Beefy Almost "Made"

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    I'm a miserable failure at that test. I can absolutely 100% detect the stereo phase differences though!

    And holy shit, my ability to hear above 13 kHz with the Crack/HD650 is abysmal. [EDIT] Hmmm, I can hear 15 Khz no problem. Never done frequency sweeps with this, I might be finally noticing that big dip in the treble response.
     
    Last edited: Jun 20, 2022
  9. MLegend

    MLegend Friend

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    Well, I don't have golden ears lol. At first, I couldn't hear any difference between the two and honestly, it's still extremely difficult for me to focus and listen for what I think the difference between the two is.

    Once I passed 10 trials and continued towards 20, I started to reliably detect a difference and choose correctly, then I would choose incorrectly. So, for my ears and these Vanatoo encore speakers, I'd say my actual success rate is closer to 10 to maybe 20%. It's pretty much a toss-up.

    What I think the difference between the two might be is the original is more full-bodied & liquid, less constrained, better sense of ease while the inverted is drier sounding with thinner & sharper sounding attacks. All of what I think I'm hearing is extremely subtle and could absolutely be wrong.

    To me, the guitar string plucks of the original have a more complete sound, whereas the inverted version sounds harsher. Sort of like edges with anti-aliasing (original) and edges without (inverted).
     

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  10. Gazny

    Gazny Friend

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    Why only 10, I was always told a sample size of 32 was pretty good.
    Turns out I don't know if I really know, maybe I do. I think I performed better the higher spl I went and mostly in the bass region.
    upload_2022-6-20_15-21-51.png
     
  11. purr1n

    purr1n Burned out

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    Practice. I'm dead serious.

    Or even if you do, and still can't tell the difference (it's not a contest), what we've established is that just because one person can't hear the difference, another person could. I'm not embarrassed to say I can't hear 15kHz tones unless they are cranked up to 120db, and even then I'm still not sure - although I know my junior high school son would be in pain.

    The problem with objectivists is that they never try any of this stuff and think because they can't hear a difference (pointing to -113db SINAD), no one else can.

    I actually thought the absolute polarity thing was bullshit, until this...
     
  12. Wilewarer

    Wilewarer Facebook Friend

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    I have a 14/22 (64%), so not really there.

    Hearing the difference is one thing, but describing it to myself well enough to A/B it is something else. I remember toying around with the polarity on my Bifrost 2 and realizing that I could hear a difference on some stuff (mostly drums), but that I couldn't tell which way was more "right", and so couldn't tell which was inverted or normal. It's not enough to just hear it.

    Maybe it would be easier if I spent more time around actual musical instruments.
     
  13. yotacowboy

    yotacowboy McRibs Kind of Guy

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    THIS! I played drums, err, percussion for about 10 or 12 years when I was a kid all the way through high school, and a bit more into college. The times I can recount actually hearing a stereo sound maybe 88% convincing reproducing the sound of a drummer going full-kill as I remember hearing/feeling it in my basement (with ear protection, of course) is twice. One was a mono system running crazy old school WE amps and giant vintage movie theater horn speaker as big as two fridges. The other was a giant MBL system. Either way, hearing live drums is one really, really good way to hear what zero phase fuckery sounds like. Shit, I miss my old Slingerland set!
     
  14. Walderstorn

    Walderstorn Friend

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    Wow i am actually impressed that i could tell the difference without a problem, after failing the 1st one. Very interesting. Are there more similar tests that compare other things?

    Correct — Current score: 9/10 (90%) — Confidence : 98.92%
    It feels like you have successfully passed the test!
     
  15. gixxerwimp

    gixxerwimp Professional tricycle rider

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    I've tried a variety of absolute polarity tests and can hear no diff. It's cool that the BF2 remote has a polarity button, but it's of absolutely zero use to me.
    (see what I did there? :p)
     
  16. Gazny

    Gazny Friend

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    upload_2022-7-8_17-50-41.png
    practice does make perfect, surprised not many others have shared their results.
     

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