When converting from DSD to PCM you need to apply a low pass filter to get rid of the noise in a DSD file.
This is interesting, are you suggesting that a DSD capture will create low-end noise that
did not actually exist in the audio source? Because the audio source I've recorded in DSD (the stereo output of a mixing console) has already been engineered to provide exactly the amount of low end desired for the final recorded product (including usage of HPF's on individual tracks of the mix.)
If the DSD recorder captures exactly what I gave it, then I suspect no additional HPF's should be required, yes?
BTW, the "DSP Studio" options seem like a very bad idea for audiophiles. By engaging these EQ settings, etc, a user would effectively be altering the sound of the music in a manner that was not intended by the mixing or mastering engineers, and downgrading the quality of the audio in the process.