Howdy,
some time has passed and i spend a long time listening to the odroid dac with and without equalizer. I prefer the alsa equalizer. So today i sat down, fired up baudline the FFT analyzer hooked everything up to my soundcard and took some measurements.
DISCLAIMER: These are no super accurate measurements, i used a cheap onboard chipset of my PC. But an equalization curve was applied to compensate the shortcomings in the HF and LF regions and cables were kept short.
As you can see the odroid dac is going down nearly 5db ... wtf were they thinking? The second picture shows the corrected frequency response using the caps equalizer plugin and alsaequal. All adjustments were made using white noise, frequency sweeps and FFT analysis. Minor adjustments were made later with the DAC back in the chain, since there are some more factors involved in frequency response and sound of the whole system.
Since the overall gain level was reduced a little the DAC doesnt crap out beeing fed -1dB full scale signals anymore, THD also improved by 5-6dB beeing tested with a 1khz sine wave. Further improvements could be made using the mbeq plugin which has more features and frequency bands, unfortunately i hab problems running mbeq and there was sometimes heavy audible distorsion, i will have to investigate that further.
For now i recommend every odroid user to try the equalizer.
