Kmixer
From Benchmark
Overview: Windows Kmixer
Windows Kmixer is the built-in software that Windows uses to mix PCM audio streams from various applications, as well as convert sample-rates and word-lengths and control volumes. 'Kmixer' is short for 'kernal mixer'.
Audio properties of Kmixer
There is very little documented on the behavior of Kmixer, as with most internal processes of major operating systems. We have attempted to test the limits of Kmixers capabilities to determine the affect it has on audio being streamed.
Sample-rate capabilities
Kmixer is theoretically capable of over 192 kHz, though we have only proven its capabilities up to 96 kHz. With sample rates up to 96 kHz, we have tested and proven that Kmixer is bit-transparent under normal operating conditions. That is, it will not affect the audio whatsoever, as long as the volume is set to 100% and only one application is playing audio.
Kmixer does not convert the sample rate of the audio unless streams of different sample rates are being mixed simultaneously. When this occurs, all audio streams of lower sample rates are sample-rate converted to the highest sample-rate being mixed. The stream with the highest sample rate is never converted.
Example: Mixing 44.1-kHz stream 'X' + 48-kHz stream 'Y' + 96-kHz stream 'Z' will result in the sample rates of 'X' and 'Y' being converted to 96 kHz.
The quality of the sample-rate conversion is usually very poor. Therefore, it is recommended to stream only one sample rate at a time.
*More information on this topic will be added as it becomes available. Thank you for your patience.
