What is the theory behind hearing it there the most?
Well it is more a hypothesis based on my own listening experience. When I heard my first ever CD (as late as 1985 - Itzhak Perlman / Ashkenasy Beethoven Sonatas) I wondered what the heck had happened to the violin sound. As an advanced violin student at the time, it sounded absolutely nothing like what a violin should sound like. This same "violin" problem persisted for many years whenever I listened to digital. It has really only been in the last decade or so where significant improvements in dithering and resampling algorithms have mitigated the profound effects 16 bit digital had on violin sound. And yes, I noticed problems with other instruments too - it's just that it wasn't nearly as irritating as it was with the violin. Maybe the fact that of all bowed stringed instruments, the violin sits closer than the others in terms of the ear's naturally sensitive frequency region (2K to 4K) has something to do with it. I then found that 24 bit went a very long way to getting violin sound back to what it really should sound like and then again further reducing noise floors as 24 bit equipment improves. So I think getting a noise floor as low as possible has a highly beneficial effect to the point where on the very best 24 bit equipment with super low noise floors and a superlative, all-digital 24 bit recording, violin sound is getting close to reality (but still not there yet). But I can add artificial noise floors to a good recording and the first instruments to "go" are the violins. Followed by the woodwind. As I say, it might have something to with the frequency range of the violin along with the extremely complex low level harmonic structure that a good instrument possesses.
I have not yet formulated a plan for how to test the unit. What I can say is that I would not have thought of half of the steps you took to make your measurements correct!
You sure you are a subjectivists and not a measurement type guy???
Yes, I am definitely a subjectivist. I always remain interested in measurement, however, if only to hopefully one day establish exactly what it is that makes sound appealing to me subjectively, but in terms of measurement. Unfortunately, having correlated measurements and subjective experience for decades now, I haven't really found any direct and repeatable relationships between measurements and what I hear, apart from obvious things such as frequency response bumps, etc. You can show me a theoretically poorer jitter plot, for example, versus a "better" one, but I might prefer the sound of the poorer one because of the particular frequencies and levels of jitter involved. Some frequencies don't harm my listening experience like others do. It is precisely the same with noise. When I got the PSP X-Dither module, it enabled me to experiment with dither noise at the 24 bit level. You'd never imagine noise so far down could produce an audible result but it does. I grew to prefer as flat a noise floor as possible. The more noise that exists at high frequencies, the more I dislike what that does for violin sound. The more noise that exists at low frequencies, the more that effects the pace, timing and clarity of the presentation. And yet we are talking about noise levels that even at their very worst, are far, far below the threshold of audibly in their own right. In any event, better just to keep the noise as evenly distributed and as flat as possible in my opinion.
What if measurements show an improvement but listening test results don't?
Well that wouldn't be anything new in audio. How many people don't hear differences between cables or 16 bit versus 24 bit. It never stopped anyone spending thousands on cables or more money on 24 bit downloads. I honestly don't think potential Entreq customers will care if you can't hear a difference. And I am 100% certain existing owners of Entreq equipment definitely won't care.
