TLDR - IMHO the audio seems to sound quite a bit better via the DVD player in the QX50 with Nav package.
What I've tried (but not abx tested, mind):
- HDtracks copy of Fleetwood Mac's "Rumors" (all time fave)
- iPhone 6s using ALAC and Bluetooth... not great, but really not as awful as I'd expected
- iPhone with album from Spotify over USB - pretty awful (the reason I started this madness)
- iPhone with album from Spotify over USB - only marginally better than Spotify (or possible identical)
- iPhone 6s using ALAC and iTunes via USB - pretty darn good
- iPhone 6s using FLAC and Onkyo HF Player - Pretty darn good, indistinguishable to my ears
- Galaxy S6 Edge using Onkyo HF Player and USB - no go?! (USB Error)
- Galaxy S6 Edge using Onkyo HF Player and Bluetooth - sounds the same as the iPhone over Bluetooth to my ears
- iPod Classic with MP3 V0 converted files over USB cable - sounds the same as the iPhone
- DVD with WAV files - won't player (should have read the manual first!)
- DVD with MP3 V0 - sounds the same as the iPod and iPhone
- DVD with WMA v9 - sounds the same as MP3 V0
- DVD with WMA 10 Pro - unplayable (D'oh!)
- DVD with WMA v9 Lossless - unplayable (D'oh!)
- DVD with audio in DVD-A mode - unplayable (shucks)
- DVD with audio in DVD-V mode - damn good!
- USB with MP3 V0 - same as iPhone/iPod/DVD
- USB with ALAC - unplayable (tried both aac and m4a extensions)
- USB with WMA v9 - pretty much the same
- USB with Apple m4a at ~500kbps - probably the best of the bunch for digital and ease of use, for me (DVD untested at this sample rate so far)
After some tests with some rather unsavory versions of this album in DVD-A (with DVD-V tracks) I noticed that they were encoded not only 24bit, but also 92hz on the DTS DVD-V tracks! This got me thinking, if a bootleg can do this, surely I could figure out how to do it via software and write a DVD with audio where video should be, with no video tracks. And so the search began...
I ended up finding this thread about lossless audio for a factory car stereo, but the process was pretty complicated for most people. After doing some reading about the lplex process, I finally stumbled upon a part of their docs that simply said: "Drag a folder of 24 96 encoded FLAC files onto lplex.exe, and it will create a DVD ISO for you."
BAM!
I tried out the technique, and though there was probably some belief bias at work here, I was pretty impressed with the results. Unlike the DTS source, this outputs PCM 2 channel to the Bose system. The settings I used when tested were driver soundstage, and I turned anything else I could find off.
Now for the (possibly?) bad news: the bass in the version I got from the FLAC -> DVD-V encoded PCM was a bit much (and not present in anything else). I had to reduce it by one to make it sound as good as the rest.
Otherwise, happy camper here as I have a few albums from HD Tracks already, and prefer having optical media in the car available in a pinch.
--nerd
NB: I'm happy to post a guide to this process wherever it might fit. I'm not much of a car enthusiast aside from really liking Nissans (and by extension, Infiniti). I've posted it here as I had read complaints about the new Bose system, and I figured this album would at least be known to many of the members.
