Digifire 7.1: Input And Output Quality
Here are the results given by Right Mark Audio Analyser for front stereo output quality with Digifire 7.1 using the following test line: Digifire 7.1 Stereo Out 1 - DMX 6Fire 24/96 Line In.
| Right Mark Audio Analyser Results | ||
|---|---|---|
| Bandwidth (from 40 Hz to 15 kHz), dB: | +0.01, -0.02 | Excellent |
| Signal-to-noise ratio, dB (A): | -82.0 | Good |
| Dynamic range, dB (A): | 78.0 | Average |
| Total harmonic distortion, %: | 0.017 | Good |
| Intermodulation distortion, %: | 0.040 | Good |
| Stereo crosstalk, dB: | -81.4 | Very good |
So results are very good, with a signal-to-noise ratio of 82 dB. Here are the corresponding graphs:
| Bandwidth | Reponse |
|---|---|
| 20 Hz to 20 kHz, dB | -0.25, +0.04 |
| 40 Hz to 15 kHz, dB | -0.02, +0.01 |
The card's bandwidth curve shows whether its frequency reproduction over the entire sound spectrum is balanced. The test is measured from 20 Hz to 20 kHz, the usually accepted limits of human hearing.
| Parameter | Left | Right |
|---|---|---|
| RMS Power, dB: | -78.6 | -80.1 |
| RMS Power (A-weighted), dB: | -80.4 | -82.0 |
| Peak level, dB FS: | -67.6 | -68.3 |
| DC offset, %: | -0.00 | -0.00 |
The second test is of noise and interference levels, and measures in particular where the card's background noise is located and its sensitivity to interference from the computing environment: power supply, transformers and monitors.
| Parameter | Left | Right |
|---|---|---|
| Dynamic range, dB: | +76.1 | +77.7 |
| Dynamic range (A-weighted), dB: | +78.0 | +79.5 |
| DC offset, %: | -0.00 | -0.00 |
Related to the above test, the dynamic range test gauges the level of noise generated in the presence of a sound signal, in this instance a sine wave (1 kHz at -60dB) at card input.
| Parameter | Left | Right |
|---|---|---|
| THD, %: | 0.020 | 0.017 |
| THD + Noise, %: | 0.023 | 0.021 |
| THD + Noise (A-weighted), %: | 0.020 | 0.018 |
The next test measures harmonic distortion or THD. It assesses the card's sound fidelity, noting the appearance of harmonics when a single but high (-3 dB) sine wave is sent to the card.
| Parameter | Left | Right |
|---|---|---|
| IMD + Noise, %: | 0.046 | 0.040 |
| IMD + Noise (A-weighted), %: | 0.039 | 0.034 |
| Parameter | G <- D | G -> D |
|---|---|---|
| Crosstalk at 100 Hz, dB: | -76 | -77 |
| Crosstalk at 1 kHz, dB: | -80 | -80 |
| Crosstalk at 10 kHz, dB: | -65 | -65 |
