Ah yes, it worked perfectly! I am still new to retroarch but I’m learning fast.
First I had to create it by selecting “Save Core Overrides” and then copy this single line from the master retroarch.cfg.
Big thank you Tatsuya79.
Retroarch is just a blessing for retro console enthusiasts and ‘in depth’ tweakers.
@Great_Dragon
I will try to make it even closer and report with the settings.
EDIT: Stock HighShelfDampen is very close indeed, no need to change anything.
EDIT2:
All other consoles should not be filtered so select “EQ.dsp” as the default in retroarch.cfg for flat frequency response.
If you keep this empty (" ") the last dsp filter will override the empty global setting.
audio_dsp_plugin = “:\filters\audio\EQ.dsp”
Thank you very much for the decision to implement it.
EDIT: Hopefully the lowpass filter in genesis plus gx sounds good, because the dsp high shelving filter might be more accurate for the task than a simple 6db/oct lowpass.
I’ve took some measurements for visual comparison and as you can see HighShelfDampen DSP filter does excellent job to match the Model1 genesis.
I tweak it slightly to 7000Hz from the stock 8000Hz and keep the stock -12db.
Sounds and measures very close to the actual hardware.
If the devs decide to implement the built-in lowpass filter in Genesis Plus GX hopefully it’ll be as accurate as this one, but some kind of low-pass/high-shelf filtering is indeed important for that beloved Genesis sound.
As far as I can hear from internet samples, other consoles do not have this filtering including NES, SNES, N64 and PSX.
This post is obsolete, since the refference Model 1 was from Youtube. See next post for more accurate measurement from FLAC sources.
I have tested and tweaked again, this time I used the FLAC version of Sonic 1 as reference which was recorded from JAP Model 1 VA1 from 16bit-Audiophile website.
The older FLAC files are from PAL Model 1 VA4 which measures exactly the same JAP model.
Both can be found here:
Here is the Model 1 and Retroarch with the new HighShelfDampen.dsp settings.
Orange line is the Japanese hardware Model 1 VA1, the Blue line is Retroarch with the new filter settings.
You mean the steep brickwall filter at 15kHz?
Genesis Plus GX dos that for some reason.
EDIT:
Yes, the slope itself is 6db/Oct Lowpass filter, but the LPF filter in iir.dll is fixed to 12db/Oct unless I am missing something that can change that.
If you’re on windows x64 could you try this test version and see if any value is good enough?
We’ve been trying to activate the lowpass filter but the behaviour isn’t as expected within Retroarch.
In Core Options put “Audio Filter” on “Lowpass”, then you can tweak the “Lowpass range” value to find something good.
I feel like 0.4 is probably it but I can’t do the measurement you’re doing to be sure of that. (it could do some strange stuff)
There’s a problem for sure, we don’t know what it is and we even asked upstream but it’s still unresolved.
I just wanted to ask you if you think that any value gives a good result, then we could put that value by default for a “LowPass ON/OFF” option in the meantime.
that sharp dip though… i think if this was how genxplus is doing resampling, could be a reason the developer thinks that the 60% was what he though was as close as how genesis should sound.
That ‘sharp dip’ at 15kHz is -30db below the fundamental, so it is nothing you will hear or should care about.
But there is always the possibility that it was intentionally programmed in.
@Tatsuya79
Please consider fixing the Range option because some genesis models have more filtering, yet some others have less.
What value 0.4 corresponds to?
Lowpass range should run from 0x0000 to 0xFFFF which is 0-65535.
The default setting is 0x9999 (39321) which is 60% of 65535.
0.4 * 65536, so it’s supposed to be 40% but we got 60% instead.
It reacts in the opposite way it’s supposed to work, we haven’t found why, and EQ is even stranger.