32bit output into 24bit capable soundcard. How bitdepth is converted i Options

[amiti]

When streaming an audio data of 32bit to a 24bit capable soundcard via ASIO, how does the hardware/drivers handle it? Are the excess bits truncated or dithered?

(I use ESI Juli@ souncard)

[amiti]

Thanks for all the help and information.

http://en.wikipedia.org/wiki/Digital-to-analog_converter

Noise is ultimately limited by the thermal noise generated by passive components such as resistors. For audio applications and in room temperatures, such noise is usually a little less than 1 μV (microvolt) of white noise. This limits performance to less than 20~21 bits even in 24-bit DACs.

Theoretically then , would it be best to dither audio stream to 20-21 bits , depending on the noise floor of the specific audio hardware?

If you are limited by thermal noise, adding more noise doesn't do anything except make the signal more noisy.

If thermal noise of hardware masks low level data from , let's say, the 21th bit and higher, digital dither could add noise at 20th bit and rescue some micro-detail before it is masked and lost. Isn't this correct?