freebsd has a kernel-level audio mixer.
Ah, okay.
netbsd is single-access.
Gotcha. I was surprised it worked in FBSD. But I've hit other issues, after long run times both OSes seem to fill swap. Haven't had a chance to do more testing to figure out what's causing it.
install a userspace sound server like audio/pulseaudio from pkgsrc?
I'm headed that way. Lots of deps (x11 stuff) as most likely it comes packaged with a gui tool. No biggie. Thanks for the heads up. I looked at it and it looks like what I need, jack doesn't suit this application.
Thanks again.