There's no basis for that claim given that Realtek has a variety of chipsets. Having sampled just a few implementations,some of them could have been the same chipset. So I still think it's a problem to generalize as even a personal opinion to all laptops that there is a "high probability" unless you have sampled like 100 laptops. LOL
Without perfect level matching, the difference in levels may yet be very slight. Since they didn't sound different then there are three possibilities:
1)I level matched successfully
2)my audio memory failed me
3)even if my audio memory failed me: there was no significant difference that I could detect using this coarse method of comparison and that the level difference was slight. (I think all of us are familiar with huge differences in audio, heavy distortion etc).
And yet, a difference of more than .1db in level matching has been shown to affect listener response. The odds of you level matching each of your test cases by ear within .1db are highly likely, and your original assertion was that they were the "same"
Now I think it's reasonable to say that they have similar SQ, since SQ is itself always a subjective assessment.
In anycase, I am not attempting to put an objective fact in front of anyone. My observation/test is justified as a healthy and equal counter to those who said that there will definitely be a marked improvement to an external DAC (see earlier in the thread): some of us are not hearing that marked difference even with an ODAC against a sigmatel.
I agree. All our tests are subjective. All of the listening test comparisons we try to make on head-fi should have an implied YMMV.