Dynamic Range
In addition to the preceding test, the dynamic range test estimates the level of noise generated in the presence of a sound signal, in this case a sine wave (1kHz at -60dB) at the card input This test gives a true idea of the card's dynamics during a recording. We achieved 91.7 dB (A), a result that is more than acceptable with a card in this price range.
Total Harmonic Distortion
In the next test, we measured the total harmonic distortion or THD. This is an examination of the audio fidelity of the card during which one notes the appearance of harmonics when a simple, but strong sinus wave (-3dB) is sent into the card. We measured a distortion of 0.006 %, which is minimal and would not be of any account to most users.
Intermodulation / Diaphony
Finally, we examined the intermodulation or diaphony. This test measures the separation between the card's left and right audio channels: in other words, the highest sound level at which one can hear on one channel before beginning to hear on the other one as well. This test is of particular interest in a multi-channel environment. With a result of -68 dB, it can't be said that we're in the top range here, but it seems to us to be certainly good enough for listening at home where the volume of the sound system rarely goes beyond this level.
