Quote:   You are indeed correct. I first replicated the experiment shown on the website, heard the noise difference, and then turned off dithering and the noise went away. I have some old stuff ripped in flac. Now I'm wondering if that had dithering on or if the noise floor is because...

Quote:   I count several unqualified statements in your post, Do you need to be challenged on those? Hopefully not because I understand generally where you are headed. Let's not get too pedantic otherwise each post grows to pages in size. :)    Cirrus has a bunch of ADC specs...

Quote:   Take a look at TI or Cirrus ADC data and you'll see A Weighting is always 3 dB better than unweighted. Yes, if your noise floor is hugely distorted that rule won't hold. If your signal of interest isn't 1 KHz that rule won't hold. But for flat noise with a 1 KHz test tone, it's 3...

Quote:     Those are the level at each frquency. You need to square and then sum/mean and then square root each level to arrive at the final level. If you do that, the ipod playing mp3 looks to have about 13 bits (best case) signal to noise ratio in the 20 to 20 KHz bandwidth. Not...

A Weighting is good for about 3 dB improvement to an unweighted noise figure.    The larger point I wanted to make was that there have been substantial measurable improvements to iPods over the years. Personally, for 2nd and 3rd order distortion, I can't hear anything lower than -45 dBc, and...

I can definitely heard the difference in the noise floor between earlier and later ipods. It's not even close. 

Modern ipods have improved quite a bit. Going back to first gen ipods, you can see the second harmonic was -75 dB in this review of the first product (-3 dBFS into 150 ohms)   http://www.stereophile.com/content/apple-ipod-portable-music-player-measurements   Modern ipods have second...

Quote:   your statement doesn't really make sense. In order to know if it was built correctly, you have to compare a measurement to a design target. If you can't identify WHY the unit sounds so good, then how can you measure to know it was built correctly?    Here's a contrived...

Quote:   Engineers realize very early in their career that the product must have something marketable to make a splash. There must be something that distinguishes the product that will induce the company to spend on advertising (versus cancelling the project), and hopefully the constant...

Take a look at the apple lightning connector. It's brilliant. The USB cable was designed by engineers with a focus on low cost. As a result, everyone is down on their hands and knees under the desk trying to plug it in, flipping it over, trying again, flipping it over, trying again and then the...

Quote:   Yes, spot on and the ear is quite poor in this regard. But it's why perceptual codecs (such as MP3) can work at all.    If you want to hear a 1 KHz tone, and there is an interfering tone at 900 Hz, if the interferer is 30 dB higher than signal of interest, then it completely...