Appendix 1: Glossary
• Noise Level
The level of any undesired system noise signals over the audio spectrum, including AC mains
hum, white noises, stray magnetic field, etc.
• SNR
Signal-to-Noise Ratio, the ratio of the maximum amplitude signal to the sum of the noise
energy. The higher, the better.
• THD+N
Total Harmonic Distortion plus Noise, measured by attenuating the fundamental signal with a
narrow band notch filter, then measuring the remaining signal which consists of harmonics of
various order. This implies the linearity of the audio converter and the lower, the better.
• Frequency Response
A measure of a device's ability to respond to a fixed input voltage, at different input
frequencies, and the difference in amplitude reproduced for each frequency. The flatter curve
at wider frequency range is better.
• Dynamic Range
The difference, usually expressed in dB, between the highest and lowest amplitude portions of
a signal which a device can linearly handle. Ideally it should be very close to SNR value and
the higher, the better.
• Crosstalk
Unwanted signal coupling from another channel of stereo or multi-channel transmission. The
lower value is better.
ASUS Xonar Essence STX Audio Precision Test Report
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