In addition on the 24/192 subject. I got info from the developer that iPeng DOES NOT handle 24/192 because of IOS7 capabilities.
I got the following answer when I asked about updating to iPeng 7.
iPeng does handle 24/96 natively but not 24/192, that's beyond iOS' caoabilities and needs to be downsampled on the server side.
Whether it plays unaltered through USB depends on your USB hardware. Obviously, the DAC has to support 96 kHz, 24 Bit playback.
In addition, only iPhones from iPhone 5 and iPads support 96 kHz sample rate, all other devices will downsample the audio to 48 kHz (iOS does that, not iPeng).
On iPads without Lightning connector you need to use the Camera Connection Kit for this to work, all other docks or adaptors will make iOS resample the audio to 48 kHz.
On devices with Lightning connector, you need to use a dock or connector that explicitly supports the Lightning connector or iOS will downsample to 48 kHz.
I believe CCK will work here, too, but haven't tested it myself. Here is a detailed article on the High-Res playback in iPeng although it precedes iOS 7.
http://penguinlovesmusic.de/2012/08/14/ipeng-goes-audiophile/
Can anyone confirm this? Or will IOS7 and iPeng upto version 1.4.16 still send 24/192 through CCKs USB port?
~~Got a reply on this from iPeng development:
~apart from the obvious question what all this ultra-high frequency stuff should be good for (definitely not sound quality, this has to add tremendous noise and for what?
Adding frequencies 10 time higher than the highest audible ones...) and the question how stable a stream requiring twice the bandwidth of an HD video stream will be over WiFi I would like to know where these user reports come from.
What player App would they have been played with? I'm pretty sure they are a myth, people probably don't know what they are measuring (something pretty common in the audiophile community). Your iPad definitely doesn't support more than 96 kHz, at least that's what the Apple engineers writing the drivers and the audio engine tell me and I trust them, they usually know what they are doing.
It's certainly possible to play 384 kHz files, they will just get downsampled, either in the App or at latest at the OS level (I am not even sure iOS supports these high sample rates at all, I somehow think it tops out at 192 kHz even on the input side, but I'm not sure here).
> Is it IOS7, iPeng or hardware limitation i.e. CCK?
It's iOS. Hardware limitations are a relative thing. USB will probably be able to do more but system load even at 96 kHz is significant, 384 kHz is unlikely to create a stable output stream and block a lot of resources on the device impacting other operations.
Apple doesn't do things like that. Even if the actual stream is passed through unaltered, there are a lot of system parameters and mixers which would have to be tuned to the same sample rate. iOS has a huge stack of rules audio sources and audio manipulation logic that's not turned off even if unused because the OS can't know in advance that it's not going to be used.
That's probably why they limited it. Pre-iOS 7 only the iPad with CCK could do 24/96 at all, all other devices where limited to 24/48.
Now iPhones with Lightning connector can do 24/96, too, but only with appropriate docks and I only recently have seen the very first ones that support it.
Best, Joerg
According to him higher than 24/96 is a no-go on any ipad. It rules out iPeng/LMS for streaming more than 24/96 and probably other software configurations?
Or he isn't telling the whole story.
And...
~> 192 kHz isn't an audible frequency, neither is 96 kHz, these are both samplerates. Both influnce the accuracy of the resulting LF-signal as does the 24 or 16 bit bitdepth.
No, they don't. I know some vendors tell you because they want to sell expensive equipment but it's just simply not true. 24 Bit can add some resolution, although even 16 bit exceed the SNR of all DACs or ADCs available today but frequencies beyond 44.1 add NO information whatsoever to the audible frequencies.
People who tell you something else have not understood how audio sampling works. The main argument for using higher sample rates is that equipment can be better tuned for these low frequencies, especially filters who by principal have a limited frequency response but all of this can usually be accomplished by simple upsampling in the DAC itself, there is no real reason to use higher sample rates for data storage or transmission.
I recommend this for a deeper understanding:
https://www.xiph.org/video/vid2.shtml
http://people.xiph.org/~xiphmont/demo/neil-young.html >
FLAC player and AmpliFlac can send out upto 24/192 signals but can not stream from another server.
They can play these files, they can not output this through USB.
Even if the USB output might be 192kHz (which I doubt) iOS will internally process the signal downsampled to 96 kHz.
> A true 1080p video needs more bandwith than a 24/192 audio signal.
Yes, but not as at 24/384 kHz audio signal.
~I don't know whether this solution maybe just transfers data as file or through some other proprietary network protocol to the DAC, which is of course possible, but you definitely can not use the iPad's own audio processing for that. I trust the guy who wrote it as to that.
So, who is fooling who?