Lossless formats (Dolby True HD, DTS-HD Master Audio) cannot pass through a coaxial cable. You must use an HDMI cable.
SPDIF is a very old standard and has serious upper limits for todays audio standards. As simple as that. It is not mere the coaxial or optical cable used for it. It is time for an upgrade and say farewell to it.
Hello, sorry for my english ....... Lossless audio formats ie Dolby True HD, DTS-HD Master Audio, cannot pass through the optical or coaxial cable only and exclusively for bandwidth problems. One might ask: but if the connection with an optical cable is practically made with optical fibers, which optical fibers work great with the internet ...... Here the problem is not the cable itself, but the connector located inside the source (when the characteristics were decided, for example of the optical cable, the Bodies in charge gave a precise and univocal address) and therefore, the connector located inside the amplifier .... So, for Lossless audio formats, the only cable on which you can listen to them is HDMI. I hope I have been able to explain why these limitations.