Ok. I did some tests. There is this Norwegian website (2L) that hosts multichannel high resolution FLAC files you can download for testing. I downloaded a 5.1 / 24 bit / 96kHz FLAC file (Mozart: Violin concerto in D major - Allegro). Using Audacity I cropped it to 40 seconds and then exported it to a lot of format variants:
- FLAC/WAV
- 16bit/24bit
- 22.05kHz/44.1kHz/48kHz/96kHz
- 2/3/4/5/6 channels
Copied these 80 files to a USB stick and tried them in USB/NET mode. Here's what happened:
Code:
2 channels
FLAC WAV
16 bit 24 bit 16 bit 24 bit
22.05kHz OK FFE OK OK
44.1 kHz OK OK OK OK
48 kHz OK OK OK OK
96 kHz OK OK OK OK
3 channels
FLAC WAV
16 bit 24 bit 16 bit 24 bit
22.05kHz OK OK FFE FFE
44.1 kHz OK OK FFE FFE
48 kHz OK OK FFE FFE
96 kHz OK OK FFE FFE
4 channels
FLAC WAV
16 bit 24 bit 16 bit 24 bit
22.05kHz OK OK FFE FFE
44.1 kHz OK OK FFE FFE
48 kHz OK OK FFE FFE*
96 kHz ok nok FFE FFE
5 channels
FLAC WAV
16 bit 24 bit 16 bit 24 bit
22.05kHz OK FFE FFE FFE
44.1 kHz OK OK FFE FFE
48 kHz OK OK FFE FFE
96 kHz ok X FFE X
6 channels
FLAC WAV
16 bit 24 bit 16 bit 24 bit
22.05kHz OK OK FFE FFE
44.1 kHz OK OK FFE FFE
48 kHz OK OK FFE X
96 kHz X X X X
OK = plays well
ok = plays with some degradation in display update and control
FFE = "File Format Error" message, file isn't played
FFE*= "File Format Error"message, file is played anyhow but stutters a lot
X = display isn't updated at all, control degraded, file starts playing but stops (often right away)
So, what's the verdict? Obviously with my SR7005 and its current firmware multi-channel WAV is
not supported when playing in USB mode. I haven't tried streaming such files but I don't think that will make a difference.
Just about all WAV files with more than 2 channels are rejected with a "File Format Error". The silly thing is that 4 channel/24 bit/48kHz WAV file also triggers this error message, but the file is actually played by the amplifier but with lots of stuttering. Stereo WAV files are played well.
Looking at FLAC, two results are puzzling: 2 channels/24 bit/22.05kHz and 5 channels/24 bit/22.05kHz both trigger "File Format Error" messages, and the files are not played. The same resolution and sample rate with 3, 4 and 6 channels work fine ?!
You can notice that the FLAC decoder is put under stress when the number of channels increase. The display update becomes less smooth, with the progress counter sometimes jumping several seconds. This is noticable with 4 and 5 channels 16 bit / 96 kHz files.
24 bit / 96 kHz is a no no with 4 or more channels. 96kHz is not supported at all for 6 channel audio.
I've also tried some of these files with my UD5005 Bluray player. It does not recognize FLAC files at all, but has no issue with playing the high resolution multichannel WAV files. I'm not sure whether it will do Apple Lossless...