Actually, that's because Airplay encodes the audio stream in ALAC (the same goes to it's predecessor, the Airport Express too). Since ALAC is a lossless format just like FLAC, so Airplay will retain all the information of the audio file, regardless of the type of audio file played from the source.

I'm also curious about these as well.

BTW i transcoded the original WAV PCM file into ADPCM using Adobe Audition 1.5. I don't know if it was originally rendered into floating point, but by default audio files loaded into Audition are rendered as 32-bit floating point. But the ADPCM files are not dithered.

Like this?

So, are there any Mastered for iTunes music files that are smashed to the levels aka badly remastered?

And does anyone tried listening to music that has been "Mastered for iTunes"? And are those encoded as "24/96" 512 kbps AAC files?

Thanks for the review about the headphones bro! I have the exact same model and I admit these are fantastic sounding cans when paired with a good EQ like RE Equalizer, which are a benefit for Android users who wanted studio quality sound out of their cans. Anyways, what the OP had described...

Don't mind if i ask, but ever heard of 24/96 AAC files?

Tidal does offer a lossless option if you are subscribing to their premium Tidal HiFi service. BTW i'm a Tidal HiFi subscriber myself. And you forgot Qobuz which also offers hi res compressed music streaming.

Oops, sorry. Again I misinterpreted your statement regarding bitrates of BT codecs.

Well except for aptX HD and LDAC, which is strictly ADPCM and therefore it does not utilize any form of psycho-acoustic models.

Of course I know AptX is a codec. I know that already, ever since it was first came out in 2012 as a new standard for A2DP. (Isn't AptX invented in the 80s? I had to find out more) BTW, thanks for the information though. Of all audiophiles here on Head-Fi, you deserve some respect bro...

Of course AptX is a container. And I did actually ABX on different sources. Sometimes i played music from my iPhone via BT AAC and compared them to my Mac playing music via aptX. Oh.. And it's evening so i need to rest..

For the last ABX test i used my Macbook Pro. And of course i use lossless files for ABXing, either on my PC or Mac. MBP natively supports the aptX codec for BT devices. And i compared two files, one AAC and ALAC/FLAC in the ABX plugin. I'm just comparing how well those lossy BT codecs encode...

For PC i used Foobar2000 with the ABX Comparator plugin. The plugin For Mac i just run Foobar2000 using Wine along with the ABX plugin. I just use the options to get the plug in to level match for me automatically.

I can't switch between AAC and aptX using my PC. However for AAC i used my iPhone 5S connected wirelessly to my headphones, while for aptX it's PC > bluetooth dongle > headphones. For ease i connected my cousin's Macbook Pro (At times i also hooked up the BT dongle to my Mac so that i could...

Well i literally used my Dell Optiplex 760 (running Win Vista) in which i installed an ASUS Xonar Essence STX soundcard which is connected to my Trond USB BT transmitter dongle via headphone out. And for listening i just used my Sony MDR-XB650BT cans.

I referred the night and day as how easily you can perceive the differences in soundstage between AAC and aptX. In terms of SQ i know it's audibly transparent. And no, i don't have any "authentic" peer data showing differences between aptX and AAC, but this is the closest that I can get to...

So far i never did any comparison between LDAC and aptX HD on real equipment (because i don't have any LDAC compatible devices - except for my Sony car stereo of course), so no, i don't even know the differences between LDAC and aptX IRL. However AAC is transparent enough to average ears on...

Yes. AAC 256 may be transparent to the average ear, but comparing them to other lossy BT codecs (e.g. aptX, LDAC) using high-end equipment is like day and night. Also,

What i really meant about the post that you quoted earlier is that i was referring to the differences in transparency between AAC and another lossy codec, which in this case is aptX, HD or not. I didn't even mentioned anything about lossless codecs.

True that, and FYI AAC is "transparent" at 256 kbps due to the fact that it is "psychoacoustically" equivalent to CD quality. However if an audiophile has the right equipment as well as the basic knowledge about what to hear in AAC then they can differentiate which (lossy) codec are transparent...

Yes, and aptX HD achieves audible transparency at 1/4 of the bitrate of a standard audio CD. (4/4 or full CD quality = 1411.2 kbps, while 1/4 = 352.8 kbps)

Let see if the upcoming Bluetooth 5.1 can permit true lossless audio streaming using true lossless compression and not aptX.

Ironically, SBC is the core technique used in popular lossy audio compression algorithms including the entire MPEG 1 Audio Layer family (MP1/PASC, MP2/Musepack, MP3 and MP4/AAC).