Is hi-res possible with Roon Speakers on an iOS or AppleTV endpoint?
AppleTV is a closed platform that only supports AirPlay, which is limited to 44.1k on the input side. The Apple TV then resamples that 44.1k AirPlay stream 48k. It’s pretty much a non-starter if quality is a concern, and there’s no indication that future revisions will be better.
As for iOS, we’ll support whatever Apple enables us to support. If the device + frameworks can support high-res output, then we will too. This article suggests that Apple hasn’t quite done everything necessary in the current iPhone 6.
Would love to know minimum requirements for a DIY endpoint using Roon for hi res.
The most important thing we require is a real, mature kernel and networking stack. Linux, BSD (incl OSX), or Windows. In the past we’ve been burned by embedded kernels, RTOS’s, network stacks, etc and will not go down that road again. In general, they lack the robustness required to provide reliable operation on messy consumer-grade networks, especially when you mix in WiFi and high bitrate streams.
It will need good enough networking hardware to keep up with the bitrates involved. DSD256 is 2.822mbytes/s + overhead. No trouble over most ethernet configurations, but $10 WiFi nubs may not provide adequate performance.
It will require enough RAM to enable substantial audio buffering at the endpoint. Tens of megabytes for high-rate content. This is a requirement for stable high-res playback over WiFi, which is an important objective for the project.
The Raspberry Pi 2 is an important early target. It has a very comfortable hardware spec–more than the minimum, but it ticks the right boxes and is very inexpensive.