[Jack-Devel] audioadapter: quality setting important when not changing sampling frequency?

Hi all, since I only need one microphone when recording I am happy with my Focusrite Scarlett 2i4. I use the 2i4 for recording and direct monitoring with the line outputs feeding a headphones amp. I use the builtin headphones amp as well, both when recording and for mixing. So far, so good. Then I wanted 2 additional outputs to feed my active speakers (Neumann KH120A plus KH805 sub). Because of my room's damping of the high frequencies (at least compared to my headphones AKG K812) I need an EQ before them. So I use a Scarlett 2i2 for this purpose, with CALF Jackhost and a Calf EQ feeding this outputs. Now I have 2 audio interfaces that can't be synchronized with a wordclock cable. So I have to drive the 2i2 for the speakers in an async way. Since I use this output only for mixing/mastering I can live with some additional latency. I tried several ways to use the 2nd interface: - alsa_out - zita_j2a - audioadapter (jack_load -i "-dhw:2 -q0 -n2 -p128 -r48000" 2i2 audioadapter) The audioadapter is the most robust solution and doesn't crash when I resize jackd's bufsize on the fly, so I'd like to stay with it. As I played around with the quality setting (-q0 ... -q4) I noticed an enormous CPU load with -q4 (sinc) but couldn't hear any differences in audio quality. -q0 sounds as good as -q4. Now my question: When the audioadapter has to resample to the same frequency (from 48000 to 48000), do higher -q settings improve the audio quality? As I understand there is no interpolation needed at all so -q0 would be enough to have a perfect audio quality. Any comments/ideas to this? Regards Holger