No stereo out on HDMI?

Question

Level 1

4 points

No stereo out on HDMI?

Can somebody confirm that the MacMini (and other Apple computers) are incapable of outputting a stereo signal over HDMI WITHOUT BLOCKING THE OTHER CHANNELS? And if this is indeed the case suggest a way around this?

The situation is as follows: I have a MacMini connected via HDMI to a 7.1 AVR (Denon AVR-X7200W) in a home cinema setup. Multichannel sound is fine, but when I play a stereo track on the MacMini I would like the AVR to use its built-in Dolby processor to post-process this signal into either Dolby Surround or DTS Neural:X. This is where the problem starts: nine of ten times this fails because the signal sent by the MacMini to the AVR is not a pure stereo signal, but a multichannel signal in which only the front left and right speakers are given a signal and the others are muted. The AVR signals this by showing it is receiving a multi-channel signal. Every now and then for reasons I cannot fathom, the Mini does send a proper stereo signal instead of a multi-channel signal and the post-processing works. Years of tinkering with sound settings in the programs used as well as the Audio Midi Setup have taught me nothing. I am still unable to force the Mini (late 2012; or my MBP laptop from 2013) to output a proper stereo signal over HDMI.

Can anyone more technical than I am explain this and perhaps even suggest a work-around?

Mac mini, macOS 10.15

Posted on Nov 18, 2020 11:31 AM

Reply

Answer 1

hcsitas

Level 6

12,920 points

Nov 18, 2020 12:11 PM in response to 9YnZhJQ8

It’s not that complicated: use HDMI for video content and USB for audio content (fed from a Mac-connected USB DAC to the Denon’s Analog In), where content is defined by file extension typically MP4 or similar for Video and MP3/FLAC/Wave etc. for audio. For MIDI, use the headphone out of the mini to the Denon’s Analog In.

The point is, you can’t fully separate Video and Audio unless they are separate at source, especially not HDMI where they’re joined at the hip by design. Not to be confused with HDMI ARC which is used by an HDMI ARC-capable TV to divert HDMI audio to a compatible home theater system (and nothing else).

For best results and also to keep things simple, use Apple TV for viewing video and the mini for other stuff. Enjoy...

Reply

Answer 2

9YnZhJQ8 Author

Level 1

4 points

Nov 18, 2020 12:45 PM in response to hcsitas

I am not trying to separate video and audio. When I still ran bootcamp Windows7 on this same MacMini there were no such problems. Why can't the Mac just pass a stereo signal on without turning it into a multi-channel affair?

Reply

Answer 3

9YnZhJQ8 Author

Level 1

4 points

Nov 18, 2020 1:02 PM in response to hcsitas

I feel obliged to answer because you have taken the trouble to reply but it isn't shedding the light on my problem that I am looking for. As I wrote in my original message, sometimes the Mini DOES pass a stereo signal on, most of the time it does not. I tinkered all afternoon with it and could not get it to work. When I returned tonight (the Mini is always on) it siuddenly and unexpectedly did work. In an hour it might no longer. It appears totally random, but perhaps it has something to do with the sort of signal that came before the stereo one?

As to your other suggestions, it is important to me to see and hear the OS because I tend to do other things with it while listening to music, so using different components to do different things is out (I do that in the rest of the house but not in the home cinema).

Reply

Answer 4

Nov 18, 2020 1:23 PM in response to 9YnZhJQ8

"Every now and then for reasons I cannot fathom, the Mini does send

a proper stereo signal instead of a multi-channel signal and the

post-processing works."

What sequence are you turning everything on?

I have an older MacMini Server (2011) that I use as a HTPC.

I have it connected to a Yamaha receiver which is the connected

to my TV. I had found that I had to power the TV first, then the

receiver, and finally boot the Mini. Any other sequence, my only audio

option in any app was stereo. If powered in this sequence all option

were available from stereo, multichannel PCM, and the DTS and Dolby.

Perhaps your situation may also be a power sequence issue since things in

"the chain" initialize in different ways if powered different. Also the possibliity

of which device is sending which configuration info to the Mini.

Just a thought.

Since then I have changed that Mini to a fully Windows10 system

and seems that all these HDMI interface issues have vanished

(and added TrueHd and DTS Master Audio passthrough

in the process as well)

Reply

Answer 5

hcsitas

Level 6

12,920 points

Nov 18, 2020 1:25 PM in response to 9YnZhJQ8

Like I mentioned, “you can’t fully separate” HDMI audio and video, which is what you’ve been experiencing i.e. you’ve gotten it to work occasionally but not fully.

The bottom line is that HDMI is not for funneling pure audio, it is headphone out and USB. Best to rejig your configuration accordingly (or fall back to older gear). Good luck.

Reply

Answer 6

9YnZhJQ8 Author

Level 1

4 points

Nov 18, 2020 1:34 PM in response to woodmeister50

That is an interesting suggestion. I had not considered that. In my case the normal situation is that the Mini will be on (it always is) and only then is everything else switched on (AVR, Projector). Sometimes, however, I reboot the Mini in the hope things will improve while everything else is on, perhaps that makes a difference, although I would have thought I would have noticed that before???

Reply

Answer 7

9YnZhJQ8 Author

Level 1

4 points

Nov 20, 2020 9:56 AM in response to 9YnZhJQ8

I have now tried out various start up sequences and am sorry to say it made no difference. The problem persists. In fact the Mini switched from passing a proper stereo signal on HDMI to multichannel while everything was on. It appears to have a mind of its own.

Reply

Answer 8

Nov 20, 2020 10:18 AM in response to 9YnZhJQ8

Maybe the best bet is to just use a dedicated USB converter

for stereo and go through the pain of switching back and forth.

Something like this gives you the option of analog connection

or digital pass through via optical or coaxial (and it only supports stereo):

https://www.amazon.com/Signstek-Coaxial-Converter-Convert-Analogue/dp/B00FEDHHKE/ref=sr_1_4?dchild=1&hvadid=77928005279718&hvbmt=be&hvdev=c&hvqmt=e&keywords=usb+toslink&qid=1605896023&sr=8-4&tag=mh0b-20

Reply

Answer 9

9YnZhJQ8 Author

Level 1

4 points

Nov 20, 2020 1:01 PM in response to woodmeister50

I guess I would have to switch the audio away from the HDMI to the DAC then in the Audio Midi app? If it recognises the DAC and lets me do that it would work. It is a pain though.

Is there anyone out her knowledge enough to be able to explain why this sort of thing happens in MacOS but not in Windows?

Reply

Answer 10

Nov 20, 2020 1:14 PM in response to 9YnZhJQ8

9YnZhJQ8 wrote:

I guess I would have to switch the audio away from the HDMI to the DAC then in the Audio Midi app? ...

Should just be able to go into System Preferences->Sound and just switch.

While there is no direct way in Apple, but there may be a menu bar based

app to allow you to switch to make it easier.

Reply

Answer 11

hcsitas

Level 6

12,920 points

Nov 18, 2020 12:51 PM in response to 9YnZhJQ8

Err, because it’s unnecessary? To tighten DRM? Falling back to W7 is the only way, stick with it. Or even better, keep it simple, get a DAC. Good luck.

Reply

Answer 12

Nov 18, 2020 12:12 PM in response to 9YnZhJQ8

Depending on the app you are using, you may need to tell

it what to send or configure it to deliver what ever the source

material is.

Reply

Answer 13

9YnZhJQ8 Author

Level 1

4 points

Nov 20, 2020 2:37 PM in response to woodmeister50

That will work too.

Reply

No stereo out on HDMI?

Similar questions