Disklavier

The encoding used for Pianosoft Plus Audio is very fragile.  It uses a 
modulation scheme called phase shift keying that is easily damaged by 
lossy compression, sample rate conversion, equalization, Bluetooth 
transmission, and other manipulation of the stream.  Be sure that all 
audio enhancement features are turned off, and close any video players.  
(Most digital video uses a sampling rate of 48 KHz, while your WAV files 
are 44.1 KHz, and the computer's audio hardware can be physically set to 
only one rate at a time.  If two applications requiring different rates 
are active, the operating system will generally configure the hardware 
for the higher rate, and the lower rate will be upconverted in software 
before mixing, which would be detrimental to Pianosoft Plus Audio.)  It 
could be that the newer OS leaves the main audio hardware at 48 KHz at 
all times, since video playback is such a popular application these days.

It could be worth trying an external, generic USB audio dongle (an 
inexpensive one with as few features as possible), then configuring the 
playback software to use that instead.  Simply trying different audio 
hardware this way might do the trick.  I've used that technique on 
laptops with faulty audio hardware that sounds passable for casual 
listening but corrupts the output too much to support player piano streams.

Mark Fontana


On 10/05/2016 02:10 AM, rightnightboy@... [disklavier] wrote:
>
> I have not had much time to tackle the problem but it comes definitely 
> from the Imac. I unearthed and old iMac G5 10.4.11 system from my 
> basement which runs 10.4.11 os ans it plays faithfully the .wav files 
> which are then recognised by the DKC and played perfectly: AH !
>
> So now why the much newer Imac isnt able to do that is a mystery . I 
> ve done eliminating games and found that it is not a software problem 
> (it occurs with all kinds of players), nor a hardware problem as far 
> as I can see ( same result from phone jack out, usb audio out, 
> bluetooth out) ... so Im a bit at lost and the machine not being 
> waranteed anymore Im hesitant to bring it to a service center with 
> such a precise and undectable flaw...
>