Marc Grissom

I think the developers would actually be happy to anwer questions about their DSP functionality on the RME forum. So I'll probably try that later.

Thanks Juha. That should be quite helpful if I decide I want a custom filter later.

I myself have always used a setting of 192k for my audio. So it's no issue for me. But whenever you see EQ presets posted online (like the Auto EQ project) no one ever mentions the sample rate. So I'm sure there are some other users getting slightly worse EQ results because they left the their sample rate setting as the default. The ADI-2 DAC will accept any frequncy you throw at it. Interestingly, the built-in plotter doesn't respond to any change in sample rate. I wonder if it's using a different...

Thanks for sharing these links. But for my purposes, I need to use whatever methods EQ APO is using. Do you by chance know if there's other parametric EQ software out there using something other than the RBJ filters?

I looked at the EQ APO plotter and it does respond to the Windows system sample rate in the same way. When I first glanced at it, I thought it wasn't. So does this mean the way our programmed EQ filters sound can be affected (albeit slightly) by our sample rate setting? I'm wondering if the difference between 44k and 192k will start to matter when you have multiple filters set above 8k interacting with each other. Yesterday I was doing just that when I realized my plots (at fs=44k) looked different...

That's interesting. In my own calculations, sample rate does actually have an effect if your F0 frequncy is close to your SampleRate/2. Take a look at my attachement. The 3 curves are peaking filters at 18k, Q=1, dB=6. I'm using the exact same equations for calculation the Biquad coefficients. But maybe I'm evaluating the transfer function differently?

Some Background: I currently working on generating my own EQ plots. I seem to get the same results as EQ APO if I choose a really large value for sample rate in my calculations. But I don't know how correct that really is. So my question is what value for variable 'srate' (Sample rate) is EQ APO effectively using? It's not tied to the Windows setting is it? Refer to BiQuad.cpp for the biquad coefficient equations.

I also wish Nvidia display setting support could be added. I frequently have to manually change color depth and dynamic range because Nvidia's default settings are always wrong. I really don't understand why Nvidia chose to have 8 bits w/ dithering as the default HDR mode. Anyway I imagine the settings could be controlled using NVAPI if you want.