2010/2/17 Lennart Poettering <mznyfn@xxxxxxxxxxx> > > > > > Hmm, so you basically tuned the USB card's DAC/ADC level to the HDA > card's DAC/ADC. > > I now measured the "Master" slider of my aureon (USB 0ccd:0028, > TerraTec Aureon 5.1 MkII) with the aforementioned dbmeasure tool and a > loopback cable. The aureon has 65536 volume steps, but > I was too lazy to measure them all. So I only measured every > 3000th. From the max volume to the min volume: > > 65536 0 dB > 62536 0.00560039 dB > 59536 0.00694678 dB > 56536 0.00616732 dB > 53536 0.00645077 dB > 50536 0.00673421 dB > 47536 -1.49514 dB > 44536 -1.49455 dB > 41536 -1.49648 dB > 38536 -2.98666 dB > 35536 -2.98486 dB > 32536 -2.98536 dB > 29536 -4.48688 dB > 26536 -6.00084 dB > 23536 -5.99928 dB > 20536 -9.00246 dB > 17536 -10.5425 dB > 14536 -16.5274 dB > 11536 -32.9435 dB > 8536 -43.4326 dB > 5536 -43.5066 dB > 2536 -43.2968 dB > 0 -43.4431 dB > > If you plot this it looks as if the card actually only implements 10 > or so discrete steps, and at around 10000 just becomes a constant > function. > > ALSA reports -47.87 .. -1.97 for this. So it seems the overall range > the USB data reports is not really that far off, but the volume > function in bteween is. > > The noise level of these measurements is < -58 dB. > > What's the next step with this measurement data? Will you take it from > here, or shall I provide you with more data? > > Lennart > How about dbmeasure the pulse device since the volume control seem also have 65536 step ? Can you provide the result for the pulse device ? _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
