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Re: Passthrough issue

Posted: 23 Apr 2018, 15:01
by davilla
I suspect related to airplay2 as it seemed to happen when airplay2 was brought in.

Re: Passthrough issue

Posted: 26 Apr 2018, 19:15
by JackOh
I have the same issue. No dts, this is terrible. I hope Apple will fix it soon.

Re: Passthrough issue

Posted: 27 Apr 2018, 12:11
by amet
JackOh wrote: 26 Apr 2018, 19:15 I have the same issue. No dts, this is terrible. I hope Apple will fix it soon.
Unless you need to see dts logo on your receiver, set MrMC to 5.1(7.1) and disable passthrough... same sound quality , you don’t loose anything by sending PCM over

Re: Passthrough issue

Posted: 28 Apr 2018, 11:24
by JackOh
amet wrote: 27 Apr 2018, 12:11 Unless you need to see dts logo on your receiver, set MrMC to 5.1(7.1) and disable passthrough... same sound quality , you don’t loose anything by sending PCM over
I don't see the DTS logo on my receiver. I have already disabled passthrough in MrMC and the receiver shows PCM. But is it really same sound quality like DTS?

Re: Passthrough issue

Posted: 28 Apr 2018, 11:43
by amet
sure, DTS is compressed .. either we decode it or your receiver does it.. either way someone does DTS -> PCM decode

@davilla or @koying might have more detailed and technical explanation :)

Re: Passthrough issue

Posted: 28 Apr 2018, 11:51
by mmihai
I am on 11.2 and staying there, however, I am not concerned about passthrough. It is quite buggy, especially in set-ups involving ARC, thus I disabled it. I am quite happy with PCM, as there is no quality loss.

Re: Passthrough issue

Posted: 28 Apr 2018, 11:59
by koying
Yep. DTS is just a way to compress sound, same as jpeg for pictures or h264 for video.
Not that different from MP3, just with far better quality and supporting multi-channels (5.1)

The compression itself loses quality (again same as for jpeg and h264), but who does the decompression, whether MrMC or the AVR, doesn't matter, as the result decoded PCM will be identical.

Re: Passthrough issue

Posted: 03 May 2018, 17:14
by Boulder
Because my AVR doesn't support 4K, I have to connect the ATV4K to my TV using HDMI. I then connect the TV to the AVR using the optical output to get audio.

The audio I have in my library varies between mono Opus and 7.1 DTS-HD MA so it can be basically anything. I have a 5.1-channel setup in the TV room. What are the settings in ATV4K and MrMC for proper audio output and minimal quality loss?

1) In MrMC, set channels to 2.0, best match, disable passthrough. In ATV4K, set output to Best possible
2) In MrMC, set channels to 2.0, best match, disable passthrough. In ATV4K, set output to DD5.1
3) In MrMC, set channels to 5.1, best match, disable passthrough. In ATV4K, set output to Best possible
4) In MrMC, set channels to 5.1, best match, disable passthrough. In ATV4K, set output to DD5.1

Re: Passthrough issue

Posted: 03 May 2018, 17:35
by cosmoxl
Boulder wrote: 03 May 2018, 17:14 Because my AVR doesn't support 4K, I have to connect the ATV4K to my TV using HDMI. I then connect the TV to the AVR using the optical output to get audio.

The audio I have in my library varies between mono Opus and 7.1 DTS-HD MA so it can be basically anything. I have a 5.1-channel setup in the TV room. What are the settings in ATV4K and MrMC for proper audio output and minimal quality loss?

1) In MrMC, set channels to 2.0, best match, disable passthrough. In ATV4K, set output to Best possible
2) In MrMC, set channels to 2.0, best match, disable passthrough. In ATV4K, set output to DD5.1
3) In MrMC, set channels to 5.1, best match, disable passthrough. In ATV4K, set output to Best possible
4) In MrMC, set channels to 5.1, best match, disable passthrough. In ATV4K, set output to DD5.1

I think it may depend on your TV's capability - what it can output via the optical. I think I've read that some TVs can only output stereo.

#3 is your best quality but you'll need to get some audio test files to make sure you're actually hearing all 5.1 channels. I have a soundbar connected to an ATV4 in the bedroom and it can't handle multichannel PCM, which is what "best possible" means. That means I only heard the front left and right channels. So, I have to set the ATV4 to DD5.1, which is your #4.

Re: Passthrough issue

Posted: 03 May 2018, 17:59
by Boulder
The strange thing is that with #3 and #4, the AVR shows PCM 2.0 as the input signal when the audio is for example Opus 5.1 in the file. If the audio is DTS-HD MA 5.1, the AVR shows Dolby Digital 3/2 with #4. I have not done any channel tests yet. The TV is a Sony XE9005.