Originally Posted by Papander
Is Realtek onboard sound just really good when compared to other onboard sounds? Because all you ever hear is how "onboard audio sucks".
The newer onboard codec chips are not that bad actually, some (e.g. ALC889, ALC898, CS4207) could even be decent if implemented properly, although on most motherboards that is not the case. For example, with the ALC887 -> Xonar D1 loop I used in this test, the dynamic range is only ~89 dB (compared to 97 in the Realtek datasheet, or 110 dB with a loopback from the Xonar output), and it is even lower when there is system - especially GPU - activity. Somewhat oddly, high CPU usage can reduce then noise by 1-2 dB.
Edit: the noise problems noted above are at least partly the result of using a sound card for testing, which degrades the performance due to grounding issues. With the much noisier onboard ADC (90 dB SNR according to the specs), the dynamic range is still close to 89 dB, and is much less sensitive to system activity. Therefore, the noise is likely not as bad in reality as these tests - including the ABX files - show. The interference at about 2.9 kHz and its multiples on the graphs below is apparently also caused by ground loops, and disappears using the onboard ADC.
There are many reasons why onboard audio is generally thought to be poor:
- older generation chips were indeed bad, with low quality DAC filtering (rolled off and distorted treble), high distortion, and high noise
- even with decent chips, the actual implementation by the motherboard manufacturer is often less than perfect
- interference problems; this is variable, but can apparently be rather bad on some machines
- low quality headphone output (note that I tested line out) for a number of reasons: high output impedance (added by the motherboard manufacturer, for example, it is 77 Ohm on my machine, of which only 2 Ohm is in the ALC887), badly implemented front panel jacks with ground loops, and digital volume control, i.e. less than 100% volume makes the already mediocre dynamic range even worse
- various random issues related to buggy drivers and/or incorrect usage (driving headphones with a line output, bad mixer settings, etc.)
- subjective bias
Originally Posted by Papander
I'm yet to test this, but I think using just an amp and onboard sound should be pretty satisfying.
Adding a FiiO E11 or other decent but reasonably priced amplifier can be an improvement, indeed, as it makes the use of the digital volume control avoidable, and fixes any issues related to the quality of the headphone output.
I have created a few graphs of the ALC887 line output, all using 24 bit samples and maximum volume. Of course, with a sound card ADC, these are not 100% reliable, but may still be interesting to compare to some low end DACs like the FiiO D5. In general, the results are not bad, but the main problem is the high noise/limited dynamic range. Therefore, an onboard DAC is most usable with dynamically compressed music and/or loudspeakers.
Edited by stv014 - 4/27/12 at 10:49am