Actually, my question is whether or not the human ear can hear the difference between Hi-SP and uncompressed in a blind test.
This comparison is essentially the same as a Hi-SP vs. wav test. Reading online (http://forums.minidisc.org/index.php?showtopic=11644&hl=) I found the specs of SP and Hi-SP. ATRAC SP is 292 kbps, Hi-SP is 256 kbps.
SP and Hi-SP are essentially the same, so this comparison should answer this. If you want to repeat with the Hi-SP that would be good too.
ATRAC SP is indeed 292kbps, but it's using an older form (I think the oldest) of ATRAC and is available on the older MD format, Hi-MD formats don't even support this ancient encoding. Hi-SP uses ATRAC3plus and is specific to Hi-MD technology only. Bitrate to bitrate comparisons are not apples to apples when dealing with different encoding mechanisms. In short, SP and Hi-SP are nowhere near the same.
So newer = better? You sure you want to stick with that theory?
But great, another comp! Do a SP to HiSP comparison and find out. I bet you wouldn't be able to tell the difference between these two compressions in a blind test.
I was basing my statement that SP ~ HiSP on this from minidisc.org:
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Ok so here's how it goes.
As far has HiMD is concerned Atrac 256kbps (also known as HiSP) is the best Atrac sounding compression you can use. While sonicstage does encode Atrac into 320kbps these are as of yet not supported on HiMD.
Here is a list of supported bitrates and my opinion on them.
PCM (1411kbps): CD quality, this has no compression and is by far the best sound quality available.
-My rating: ***** (5/5)
Atrac3+ HiSP (256kbps):Highest quality Atrac compression. Very comparable to the original Atrac (which had a bitrate of 292kbps), this compression is almost impossible to tell apart from the original PCM source.
-My rating: ***** (5/5 because the whole point of compression is to let you store more audio in the same space and for all intensive purposes this sounds the same as PCM)
<snip of lower bitrates>