Harley's at it again!!! - FOQUS (bastard son of MQA)

[RandomEar]

Pretty good fit! The FOQUS filter appears to have a slightly higher FWHH because I matched the peaks, so the area scaling isn't perfect.

(Time scale stretched to fit)

 

[amirm]

Hmmm... took a look at the whitepaper. This is the supposed impulse response for their ADC:

View attachment 557243
That's just... a Gauss filter or maybe an even more trivial moving average? That will start to droop beginning at 0 Hz and will be down multiple dB by 20 kHz, right? This is garbage. What am I missing here?

Asked ChatGPT Pro to compute the frequency response from above:

• 10 kHz: -0.2 dB
• 20 kHz: -0.6 dB
• 30 kHz: -1.2 dB
• 40 kHz: -2.2 dB
• 50 kHz: -3.5 dB
• 60 kHz: -5.0 dB
• 70 kHz: -6.9 dB
• 80 kHz: -9.2 dB
• 90 kHz: -11.8 dB
• 96 kHz: -13.6 dB

So not too bad for 192 kHz sampling if the input is already band limited way before Nyquist.

 

[Cbdb2]

What a terrible white paper. And all the references are themselves! So its just a regurgitation of there old BS.

 

[kyuu]

What a terrible white paper. And all the references are themselves! So its just a regurgitation of there old BS.

I mean it is quite handy, in a sense. Lets us know quite quickly that there's nothing new here and it has just as much merit as MQA.

 

[Philbo King]

There is one born every minute, and 2 to take their money...