Can’t eliminate Crosstalk - XL2546

[k2viper]

Thanks! There's also commands
IncControl X Y - increases the value of control X by Y
DecControl X Y - decreases the value of control X by Y

I should try it with LG.
Current (default) values of 0x4E and 0x4F looks similar to default Area 0000 and Intensity 18, just in in other then Benq's values range.

[PedanticFool]

Thanks! There's also commands
IncControl X Y - increases the value of control X by Y
DecControl X Y - decreases the value of control X by Y

I should try it with LG.
Current (default) values of 0x4E and 0x4F looks similar to default Area 0000 and Intensity 18, just in in other then Benq's values range.

Remember the values listed are in hex too, so 0x0180 = 0384 in decimal. You'll probably want to look for something which returns 0x0012 (18 decimal), at least that's how it works on my BenQ.

[k2viper]

The thing is, that LG 27GK750F-B uses Mstar controller and also, default XL2546 240hz crosstalk looks very similar to LG's crosstalk at 240hz (i posted photos at 1st page of this thread). They look literally the same in terms of strobe phase (area).

That makes me suppose, that actually both Benq XL2546 and LG just use some "default" Mstar controller strobe settings and that's why their crosstalk look so similar.

Also Benq is known to have VCPs to control strobe settings via 0x40 or 0x4D/E/F, and LG also reports 0x4d, 0x4e, 0x4f as valid controls.
Too much to be just a coincidence.

If, as I suppose, 0x4E control is an LG's Area setting and it defaults to 0 (hex 0000), I should try "SetControl 4E 0064" and it should set 0x4E to 0064 which is 100 in decimal? If I guessed right I should see a difference in crosstalk.

Also as I suppose, if 0x4F control is an Intensity setting and defaults to 384 (hex 0180), I should try "SetControl 4F 0200" and it should set 0x4F to 0200 which is 512 in decimal.

Sorry for the inconvinience, I'm not used to hex values yet.

[PedanticFool]

Ah, does that LG monitor not expose the current strobe adjustment values anywhere in the OSD? In that case yeah maybe the best you can do is try to set those unknown controls, that sounds like it could be risky though. I'm still not very familiar with VCP codes but what if one of them disables your backlight so you can't see the OSD, or messes with crucial timing settings, that sort of thing? Setting new values for unknown/undocumented codes is not something I'd like to try personally at least without more research on the possible dangers. Also iirc the XL2540/XL2546 use a Realtek scaler, not Mstar.

[k2viper]

No, OSD has nothing except just strobing toggle on/off. There's also no known way to get to service menu.
Am I right with SetControl syntax?

[k2viper]

Tried SetControl 4f, 4e, looks like LG doesnt accept other values then defaults. If I set another value it just returns error.
Or these controls are firmware locked, or I havent yet tried valid values to set...

[PedanticFool]

Heya k2viper,

The screenshot you shared https://ibb.co/kXEWvS does not actually list every supported control code even though it implies it does. At least on the XL2540 0x40, 0x41 and 0x42 are missing from that list and the capabilities string completely but they still work just fine. You might find other such hidden codes exist for your LG too.

Those values, 0x3802 and 0x0180 could be interpreted internally as two separate 8 bit values. So 0x3802 would expand out to 0x38 (dec 56) and 0x02 (dec 2), likewise with 0x0180. Again I've almost no experience here but it's something to keep in mind.

Since you have the option to at least enable/disable strobing in the OSD you could try something like this:

1. Disable strobing in OSD, use Tools>Refresh VCP table to dump the result of all supported codes to the log then copy the opcode results to a temp file.
2. Enable stobing in the OSD, use Tools>Refresh VCP table to dump all the results again then compare the log result to the one from earlier.
You're looking for the value which changed to indicate strobing is enabled. If you can find this it's possible the other codes to tweak strobing might be located nearby.

If the above fails it's still possible that there are hidden VCP commands not revealed in the capabilities string. The only way I know to check them all though is to manually run GetControl on every code from 0x00 to 0xFF.

[k2viper]

I already dumped VCP table here: viewtopic.php?p=31669#p31669
Havent found which VCPs changed, though. Dumps look identical.

Hm, an interesting idea you shared, I also may GetControl not on every single code, but just on codes which are not in capabilities string.
I already checked "manufacturer specific" codes and none of them seem to control strobing.
But still it's possible that 4E, 4F are that strobe control codes but they're firmware locked and not changeable (return error on a non-default value set)