On Sat, 9 Apr 2011, Sergei Steshenko wrote: > On Fri, 8 Apr 2011 21:55:11 -0700 (PDT) > Bill Unruh <unruh@xxxxxxxxxxxxxx> wrote: > > [snip] >> The microphones definitely do not have -90dB noise floor unless you are >> recording stuff at 120-130dB SPL. > [snip] > > The level might be 120-130dB SPL, but neither myself nor my neighbors will hear > it that loud - again, I am not going to go into details of my rig. > > Also, the processing is heavily DFT based, so SNR in the whole band and measured > results confidence are quite different things. > > For example, modelling part of the whole process I was able to obtain timing > accuracy of 0.2 samples having SNR of just 10 power-wise (Gaussian noise). > > Anyway, I want the soundcard to be "non-existent", i.e. I want to achieve the > situation that soundcard noise contribution is negligible compared to what I > already have in my system. Sure, but nocando. The soundcard is an amplifier and also an A-D. 90dB is 10^-4.5 in amplitude. If that were distortion it would be .003%, which is really really hard to do. Anyway, have you looked at the SN of the soundcard? If you run it at 16 bits, do you get overruns as well? Also, it is a bit weird that sox works since it is also using alsa. > > Regards, > Sergei. > -- William G. Unruh | Canadian Institute for| Tel: +1(604)822-3273 Physics&Astronomy | Advanced Research | Fax: +1(604)822-5324 UBC, Vancouver,BC | Program in Cosmology | unruh@xxxxxxxxxxxxxx Canada V6T 1Z1 | and Gravity | www.theory.physics.ubc.ca/ ------------------------------------------------------------------------------ Xperia(TM) PLAY It's a major breakthrough. An authentic gaming smartphone on the nation's most reliable network. And it wants your games. http://p.sf.net/sfu/verizon-sfdev _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
