Tag:

audio fundamentals

Audio Theory

Understanding audio measurements: Crosstalk

by nihtila January 8, 2017

written by nihtila

Expresses “leaking” between channels; it is measured by driving a stimulus signal in one channel while listening to the other.
Crosstalk is expressed as a ratio between the quiet undriven channel and the stimulus in the driven channel, and given in decibels.

January 8, 2017 0 comment

Audio Theory

Understanding audio measurements: THD+N vs. amplitude and frequency

by nihtila January 8, 2017

written by nihtila

Presents the unwanted part of signal – something that was not put there and should not be there.
THD+N vs. amplitude graph is important as it reveals SNR, dynamic range, and THD+N ratio; all are expressed as ratio compared to a specified signal level.
The difference between THD+N level and THD+N ratio must be understood.
Signal level, signal frequency, and measurement bandwidth must be known (or guessed) when analysing results.

January 8, 2017 0 comment

Audio Theory

Understanding audio measurements: noise, SNR, and dynamic range

by nihtila January 8, 2017

written by nihtila

SNR is a ratio of two measurements, level and noise measurements, expressed in dB.
Signal level, measurement bandwidth, and weighting filter must be defined.
Dynamic range is like SNR but noise is measured in the presence of small signal; results should be the same.

January 8, 2017 0 comment

Audio Theory

DAC digital filters and their impact in time and frequency domains

by nihtila January 7, 2017

written by nihtila

Many DAC chips and devices using those chip have user selectable options for digital filter response to fine-tune tonal characteristics. I will take PCM1794A used on H-DAC as an example and see what effects these filter types have on impulse and frequency responses. This is just scratching the surface of the topic by briefly introducing some technical effects that can be measured. Tonal characteristics are not discussed here; those are highly subjective and a topic of another post (or debate).

January 7, 2017 1 comment