HD Audio questions

[fluke281]

My surround sound receiver cannot receive HDMI input, only SPDIF. Therefore, I use Blu Ray hardware players with Coax outputs. These players will convert HD audio to Dolby Digital. When I leave the DTS-HD or True HD on the backup (unchecked remove HD audio), the players sometimes convert the audio to Dolby Digital and sometimes not.
It seems that DTS-HD, when checked to remove it, only gives you Dolby Prologic II, which is synthesized from a stereo track and is not true surround sound.
However, with True HD, when "remove HD audio is unchecked," but convert to AC3 is checked, gives true surround sound. This works with all of my players.
Is this correct?

[Rich86]

If your title has Dolby TrueHD, and you are feeding digital audio to your receiver over optical or coax, you should be getting the core dolby digital over that connection.
If your title has DTS HD Master and you are feeding digital audio to your receiver via optical or coax, you should be getting the core DTS signal.
This assumes your receiver is capable of Dolby Digital as well as DTS, and your player is set to feed dolby digital and dts to your receiver if that is the signal available on your title.
I do not believe blu-ray players will convert dts to dolby digital under any circumstances. If your player is not set to output dts if available, or your receiver is incapable of handling dts, I expect your player will convert the core dts multi-channel audio to pcm 2 channel.

[fluke281]

Dolby True HD and SPDIF

This is interesting because the Dolby web site claims that Dolby True HD is uncompressed. Since SPDIF will only pass two uncompressed PCM channels or at least 6 compressed channels, it would seem that Dolby True HD will not pass through SPDIF. Hence, the need for these players to convert to Dolby digital. Someday, I will have an HDMI audio capable receiver but they are about $500 now.

[Rich86]

This is interesting because the Dolby web site claims that Dolby True HD is uncompressed. Since SPDIF will only pass two uncompressed PCM channels or at least 6 compressed channels, it would seem that Dolby True HD will not pass through SPDIF. Hence, the need for these players to convert to Dolby digital. Someday, I will have an HDMI audio capable receiver but they are about $500 now.

Dolby TrueHD IS a lossless audio codec and WILL NOT pass through a spdif connection. But it DOES provide a lossy Dolby Digital multi-channel "core" that CAN be handled via coax or optical digital audio connection.
The same goes for DTS HD Master - it WILL NOT pass through a spdif connection, but it DOES include a standard DTS lossy multi-channel core that WILL pass through a spdif connection, IF you have set your blu-ray player to pass on DTS as DTS, AND your receiver can handle DTS.
If the source disc has ONLY DTS audio on it, and NO dolby digital option, your player WILL NOT convert the DTS audio track to Dolby Digital to pass over a spdif connection. It will pass on either the lossy core DTS signal track OR a 2 channel pcm track, depending on your blu-ray player setup and receiver capabilities.

So - is your blu-ray player set up to pass on a DTS signal as DTS?
Is your receiver DTS capable?
If you provide the make and model blu-ray player and receiver you are using, you might get better assistance.

[fluke281]

Audio problem solved using DVDFAB media player 2

I used a computer with optical output to connect to my surround sound receiver and test the backups. The new DVDFAB media player 2 has the option (in Settings) of "DTS capable receiver." When I clicked only this box, there was no audio. Audio returned with the AC3 option. So this receiver is incapable of DTS. I connected the Blu Ray player to another receiver using a twenty foot long cable made of quad shield coax and RCA audio adapters and the DTS works. Thanks to all.