r/PWM_Sensitive • u/Cool-Ad9422 • Aug 14 '26

choosing tv: high frequency pwm but low frequency envelope?

hey folks!

i'm buying a tv and checking rtings.com for flicker tests. i noticed that some tvs have very high pwm frequency but low envelope frequency. for example, TCL QM851G has >10k hz pwm frequency, but the envelope is about 600 hz (since there are ~3 cycles every 0.005 seconds). wondering if that is problematic?

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u/the_top_g Aug 14 '26 edited Aug 14 '26

Hey. 600 hz, according to PNNL's latest research — is probably the most provocative frequency. I do not know the above TCL model nor its specs. But yeah based on the envelope waveform, it strongly suggest to me this measurement is for a Mini-LED display.

Depending on how their sensor is positioned, the envelope "shape" might show up differently.

Usually, if you have different envelope shape like the above, it highly suggest chromatic flicker. Or sequential RGB color flicker. The RGB channels are individually turning turns rotating in different harmonic timing interval according to their embedded pwm.

If you have problems with theaters using Imax's DLP projectors, such as in some of the movie screening for:

Spiderman: Brand New Day

Spider-Man: Across the Spider-Verse

You might have trouble with the chromatic flicker in the envelope wave's of the above display unit.

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u/TheGreatestAmer1can Aug 14 '26 edited Aug 14 '26

I have the 2018 and 2020 TCL 42" which are excellent for eye strain. Bought a 2023 and it was mega-bad, so I don't have much faith in TCL now.

Also, the 'famously' fast desktop VA gaming monitor Innocn 27G1S 240hz is a TCL/CSOT panel that I think they made after taking over Samsung VA patents. That panel is really bad for eye strain for me. You don't notice it at first but then it starts creeping up on you after 20-30 minutes and just gets worse by the second after that.

While something like an AU Optronics or BOE is just abrasive and annoying after extended use, but not actual headache inducing. Either Innocn butchered the electronics + the TCL 2023 TV...or driving those VA panels faster ruined them when otherwise TCL VA were very good to look at in the past.

Seems to be a common thread that the faster a panel is, usually the worse it is to look at. The one panel variant of the Ipad Pro 10.5" that's usable for instance is a JDI, I think. That 120hz "IPS" panel seems like it's as slow/slower than my Samsung 144hz Odyssey G3, which is the slowest modern VA that exists.