MP 7,1 Lacking Sound quality via TB->HDMI Adapter

[chfilm]

Hey,

I have the following setup, attached to my mac pro is a Promise Pegasus Raid via TB3->TB2 Adapter, and behind that raid is a AV Receiver via TB2->HDMI Adapter. It works pretty much flawlessly as in I hear sound from my speakers, and if I play back a movie that has Dolby Digital Audio, my entire 5.1 system fires up as expected.

There's only one issue: When simply listening to music via the music app, somehow the sound lacks deepness or richness, it sounds a bit thin and my subwoofer won't even turn on. If I switch to Airplay to the receiver the difference is night and day, a lot more rich and deep sound, and the sub lights up immediately.

It's not AWFUL, tooke me two weeks to even notice it, but now I'm really missing the deeper frequencies.

Any idea why this could be happening or what I could do to get full quality audio output all the time of my 7.1?

 

[erroneous]

If you look in Audio Midi Setup, what does the HDMI adaptor show as its output and Speaker settings?

 

[chfilm]

If you look in Audio Midi Setup, what does the HDMI adaptor show as its output and Speaker settings?

Hmmm, here are screenshots from the settings. Speaker config was set to 2 speakers strangely, I set it to 5.1 surround but it had no effect, and if I click on the speakers to test them, the only ones that output the test noise are front left and front right, the others remain silent.


I mean what's really strange is that Airplay also just outputs stereo and from that stereo signal, the AVR takes the according frequencies and cuts some off the main speakers and assigns them to the sub, while the stereo signal coming from my mac seems to be absolutely lacking low frequencies. There's just like no bass.
On my trashcan it always worked perfectly fine... could it be the TB3->TB2 adapter? Would be strange, since in general, for example when watching a 5.1 encoded movie with VLC it works perfectly.

 

[flygbuss]

I think you might mix things up a little.m, no offense.
A stereo source always remains a stereo (two channels) source if it’s not an encoded LtRt Signal.
A 5.1 signal contains six discrete channels, one of them is the subwoofer (LFE)
So if your receiver receives a stereo signal it will (if configured to do so) split the output Signal depending on the frequencies to your speakers and to the subwoofer. E.g. channel 1 to the left speaker, channel 2 to the right one but only frequencies above 80Hz. Everything below 80Hz from channel 1+2 is going straight to the subwoofer.

In comparison, if your receiver is receiving a 5.1 audio signal it’s gonna be routed straight to the designated speakers without frequency separation.
(The LFE channel comes already trimmed to lower frequencies)

So I think there is either something wrong with the adapter or with the configuration of your hdmi input on the receiver side.

Edit: since multichannel seems to work just fine, I assume that the receiver either won’t separate the frequencies correctly when fed through the hdmi, or the signal lacks those deepe frequencies which I find unlikely.

 

[AidenShaw]

my entire 5.1 system fires up as expected

Is it a MacPro 5,1, or a 5.1 multi-channel audio setup?

 

[chfilm]

I think you might mix things up a little.m, no offense.
A stereo source always remains a stereo (two channels) source if it’s not an encoded LtRt Signal.
A 5.1 signal contains six discrete channels, one of them is the subwoofer (LFE)
So if your receiver receives a stereo signal it will (if configured to do so) split the output Signal depending on the frequencies to your speakers and to the subwoofer. E.g. channel 1 to the left speaker, channel 2 to the right one but only frequencies above 80Hz. Everything below 80Hz from channel 1+2 is going straight to the subwoofer.

In comparison, if your receiver is receiving a 5.1 audio signal it’s gonna be routed straight to the designated speakers without frequency separation.
(The LFE channel comes already trimmed to lower frequencies)

So I think there is either something wrong with the adapter or with the configuration of your hdmi input on the receiver side.

Edit: since multichannel seems to work just fine, I assume that the receiver either won’t separate the frequencies correctly when fed through the hdmi, or the signal lacks those deepe frequencies which I find unlikely.

the problem can’t be on the receivers side since it used to work just fine before I upgraded the Mac Pro.. it’s really more like the stereo signal is lacking the deep frequencies while special 5.1 files that output signals straight to the correct channels work because there’s the separate LFE signal directly for the sub...
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Is it a MacPro 5,1, or a 5.1 multi-channel audio setup?

It’s a 5.1 sound system, otherwise I had written 5,1

 

[flygbuss]

the problem can’t be on the receivers side since it used to work just fine before I upgraded the Mac Pro.. it’s really more like the stereo signal is lacking the deep frequencies while special 5.1 files that output signals straight to the correct channels work because there’s the separate LFE signal directly for the sub...
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It’s a 5.1 sound system, otherwise I had written 5,1

That’s strange.
because DAC happens inside the receiver so it should technically be the same unless the signal is compressed somehow.

what happens if you connect the receiver without the raid?

 

[MarciaFunebre]

It can be a problem regarding the communication between computer and receiver. HDMI is a really shi-tty and unstable way to connect audio but pretty much the only convenient thing these days (plus you cannot prevent your Mac from treating it yet as another video screen which is so annoying).

Some devices simply don't communicate well with each other. When I used a Trashcan Mac Pro I had to use a little EDID hacking box (by Gefen) in between the Mac and the processor (receiver) (in my case an Emotiva processor) because the EDID information did not match up. Strangely now with the 2019 Mac Pro I don't need it anymore but still - every once in a while, and especially when playing stereo and surround sound files randomly after another, the processor gets stuck and I have to manually switch audio sources and back again before it can detect the 5.1 signal correctly. Now, theses things can randomly happen and take on any variation depending what kind of equipment configuration you use. Most likely the culprit is the fundamentally flawed implementation of the HDMI protocol. Sometimes it also helps to get another HDMI cable. Some do better than others. Trust me, I have gone through months of trouble shooting on this matter.

The most elegant way for dedicated surround sound (music) is to get a decent audio interface with enough analog outputs to and use the 7.1 analog in on your processor/receiver. Although it must be noted that a lot newer receivers/processors don't have them anymore. I think Marantz still does but even Emotiva don't have them anymore and they do not offer an appropriate alternative e.g. by updating their ancient USB connection to at least USB 2.0 which would solve the issue in such an easy way because that could handle the bandwidth needed for 5.1 .
The only issue with this then is that if you have a playlist with stereo files and 5.1 files, the stereo files will not take advantage of the audio modes on your processor such as upmixing Dolby Prologic etc. You only get 5.1 PCM when that is what you feed it and you get the naked stereo sound (no usage of subwoofer etc) when you feed a stereo signal through it. Either you have to switch the audio input or use HDMI and deal with its bugginess...

 

[flygbuss]

@chfilm

I would try a usb c to hdmi cable first and see if that changes anything.

Those are about 20,- EUR on German amazon.

 

[goMac]

It’s your receiver.

Your receiver is outputting the stereo signal exactly as it receives it. The receiver is probably configured by default to reproduce sound accurately. Changing your Mac MIDI settings won’t change a thing. Your Mac won’t convert a stereo output into surround.

Most receivers have a setting to remix the stereo signal into stereo + sub. It varies from receiver to receiver, so I couldn’t tell you where it is. But I know my Pioneer Elite had a setting I had to flip for my HDMI connected cable box. Before I flipped it, stereo content from my cable box wouldn’t cause the subwoofer to fire.

Your AirPlay input was probably already adjusted by the receiver manufacturer. That’s why it produces stereo + sub from a stereo only single.

It’s not the cable or adapter or Mac. Receivers almost always will not process a stereo signal into stereo + sub out of the box. They’re setup to produce sound exactly how the input from the HDMI signal was mastered.

 

[MatsSkoe]

I have problems with sound output quality to external devices when VLC volume is above 100%. However, that is much worse than missing deeper frequencies..

 

[nicho]

It’s a 5.1 sound system, otherwise I had written 5,1

Why would you write 5,1 for a previous gen mac when you call your current one a 7.1 in your first post and signature

if mixing up commas and periods confuses even yourselves, how do you think people in other countries feel. 1.000% more confused.

 

[flygbuss]

It’s your receiver.

Your receiver is outputting the stereo signal exactly as it receives it. The receiver is probably configured by default to reproduce sound accurately. Changing your Mac MIDI settings won’t change a thing. Your Mac won’t convert a stereo output into surround.

Most receivers have a setting to remix the stereo signal into stereo + sub. It varies from receiver to receiver, so I couldn’t tell you where it is. But I know my Pioneer Elite had a setting I had to flip for my HDMI connected cable box. Before I flipped it, stereo content from my cable box wouldn’t cause the subwoofer to fire.

Your AirPlay input was probably already adjusted by the receiver manufacturer. That’s why it produces stereo + sub from a stereo only single.

It’s not the cable or adapter or Mac. Receivers almost always will not process a stereo signal into stereo + sub out of the box. They’re setup to produce sound exactly how the input from the HDMI signal was mastered.

That’s what I was thinking as well, but he says it worked perfectly fine with his previous nMP 6,1
So as long as he didn’t replace the receiver as well or somehow reset or change the sound processing on that input..

Maybe worth a shot to first have a look if the receiver audio settings are identical on hdmi and airport input.
Is this a Yamaha?
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Why would you write 5,1 for a previous gen mac when you call your current one a 7.1 in your first post and signature

if mixing up commas and periods confuses even yourselves, how do you think people in other countries feel. 1.000% more confused.

How about we focus on the topic instead. English is obviously not my nor his first language. So mistakes happen eventually. But from the context of his post it’s pretty obvious what he’s asking for and talking about.
Also, if I’m not mistaken the German spelling for the cMP would be 5.1 not 5,1
I do appreciate help to improve language skills but no need to be picky about it.

 

[nicho]

How about we focus on the topic instead. English is obviously not my nor his first language. So mistakes happen eventually. But from the context of his post it’s pretty obvious what he’s asking for and talking about.
Also, if I’m not mistaken the German spelling for the cMP would be 5.1 not 5,1
I do appreciate help to improve language skills but no need to be picky about it.

I was just trying to engage in light humour

That’s what I was thinking as well, but he says it worked perfectly fine with his previous nMP 6,1
So as long as he didn’t replace the receiver as well or somehow reset or change the sound processing on that input..

Logically it's something to do with the mac, since that's (supposedly) the only thing that changed and some parts still work fine. I wonder if it's related to the equaliser in the music app, if OP had a higher bass setting on his previous MP.

 

[flygbuss]

I was just trying to engage in light humour



Logically it's something to do with the mac, since that's (supposedly) the only thing that changed and some parts still work fine. I wonder if it's related to the equaliser in the music app, if OP had a higher bass setting on his previous MP.

I thought about that as well but wouldn’t it sound similar via AirPlay then?
Depending on the receiver (brand, model) it could be just a single button to change eq settings and easily happen accidentally.

Check the receiver first, if it is not the culprit try a different hdmi cable / adapter

 

[chfilm]

I thought about that as well but wouldn’t it sound similar via AirPlay then?
Depending on the receiver (brand, model) it could be just a single button to change eq settings and easily happen accidentally.

Check the receiver first, if it is not the culprit try a different hdmi cable / adapter

I honestly don’t know what I should change in the receivers settings. There are no special input settings afaik and I surely didn’t change them. if can’t be EQ Settings either.
I’m gonna try attaching it directly to the HDMI port, maybe that will help..

 

[flygbuss]

I honestly don’t know what I should change in the receivers settings. There are no special input settings afaik and I surely didn’t change them. if can’t be EQ Settings either.
I’m gonna try attaching it directly to the HDMI port, maybe that will help..

I don’t know the brand but with Yamaha for example there are preconfigured settings like ‘concert’ and stuff. I assume the input source changes automatically as soon as you feed the receiver via AirPlay?

But if you’re certain that nothing has changed on the receivers side do some testing with different cables.

Here is one I’d start with because it’ll rule out any adapters as well:

uni USB C zu HDMI-Kabel(4K@60Hz), USB Typ C zu HDMI 2.0 Kabel [Thunderbolt 3 kompatibel] für MacBook Pro 2019/2018/2017, MacBook Air, iPad Pro, Surface Book 2, Samsung S10 und Mehr-Grau-1.8m/6ft

uni USB C zu HDMI-Kabel(4K@60Hz), USB Typ C zu HDMI 2.0 Kabel [Thunderbolt 3 kompatibel] für MacBook Pro 2019/2018/2017, MacBook Air, iPad Pro, Surface Book 2, Samsung S10 und Mehr-Grau-1.8m/6ft

www.amazon.de

 

[s66]

Look at the receiver. (and only there).
Mostly all 5.1 and better receivers have setting (or can measure it themselves for the more expensive ones) to tell them what frequencies (they can expect) their speakers be able to reproduce, and act accordingly and e.g. siphon off low frequencies toward a subwoofer (or not do that). Those settings combined with per source instructions to do that or pass it "pure" etc. make up what a receiver does with an input signal. That reaction of the receiver will also change depending on it receiving more or less channels on the input.

It differs greatly between brands and models in how it can be setup and configured.

If you receiver did a different ("better" is very subjective) job previously: all that might have changed is that you used a different input connection, that it got reset somehow, etc.

 

[chfilm]

Look at the receiver. (and only there).
Mostly all 5.1 and better receivers have setting (or can measure it themselves for the more expensive ones) to tell them what frequencies (they can expect) their speakers be able to reproduce, and act accordingly and e.g. siphon off low frequencies toward a subwoofer (or not do that). Those settings combined with per source instructions to do that or pass it "pure" etc. make up what a receiver does with an input signal. That reaction of the receiver will also change depending on it receiving more or less channels on the input.

It differs greatly between brands and models in how it can be setup and configured.

If you receiver did a different ("better" is very subjective) job previously: all that might have changed is that you used a different input connection, that it got reset somehow, etc.

I’m aware of the settings in the receiver regarding hand off to the sub or not, but even if I set it so that doesn’t hand anything off to the sub (except dedicated lfe signals in movies), the sound coming from the front stereo speakers still sounds way thinner than if I send it over airplay.
like there are just a lot of deeper frequencies missing.. also the signal is very loud actually, a lot louder than it used to be, I always have to dial down the receiver quit bit.
It’s a DENON receiver.
There’s not really anything I can set regarding the input, I just have it set to pass through instead of any strange concert hall or fake surround modes..

 

[goMac]

I’m aware of the settings in the receiver regarding hand off to the sub or not, but even if I set it so that doesn’t hand anything off to the sub (except dedicated lfe signals in movies), the sound coming from the front stereo speakers still sounds way thinner than if I send it over airplay.
like there are just a lot of deeper frequencies missing.. also the signal is very loud actually, a lot louder than it used to be, I always have to dial down the receiver quit bit.
It’s a DENON receiver.
There’s not really anything I can set regarding the input, I just have it set to pass through instead of any strange concert hall or fake surround modes..

I think one issue is it’s a digital signal. Adapters, cables... won’t make a difference. Digital signal will be exactly the same from one adapter to another. The Mac Pro hardware shouldn’t really matter either. macOS the one mixing the digital signal. You could try direct attaching, but again, really unlikely this is a hardware issue on the Mac side.

That brings it down to two possible issues. The source is providing bad data. It’s not impossible but I’ve never seen that on a Mac connected to a receiver so far. You can check what happens if MIDI Utility is set to stereo for stereo output, but my guess is the receiver is already moving into a stereo mode on it’s own. Maybe the soundstage is configured improperly in the MIDI utility?

If it’s not the source, then it has to be the receiver. Try multiple inputs, check the settings, etc etc. I think the reason that most people are commenting on the receiver is that’s the one device in the chain that has the hardware to distort the digital signal.

 

[flygbuss]

I think one issue is it’s a digital signal. Adapters, cables... won’t make a difference. Digital signal will be exactly the same from one adapter to another. The Mac Pro hardware shouldn’t really matter either. macOS the one mixing the digital signal. You could try direct attaching, but again, really unlikely this is a hardware issue on the Mac side.

That brings it down to two possible issues. The source is providing bad data. It’s not impossible but I’ve never seen that on a Mac connected to a receiver so far. You can check what happens if MIDI Utility is set to stereo for stereo output, but my guess is the receiver is already moving into a stereo mode on it’s own. Maybe the soundstage is configured improperly in the MIDI utility?

If it’s not the source, then it has to be the receiver. Try multiple inputs, check the settings, etc etc. I think the reason that most people are commenting on the receiver is that’s the one device in the chain that has the hardware to distort the digital signal.

I agree about the digital signal but I never experienced a mismatched configuration for a mac stereo output within audio midi setup.
But I do experienced awkward behavior of receivers fed audio via hdmi. Sometimes changing just the cable can make a difference, especially with hdmi.

 

[s66]

If you are 100% sure (I'm not convinced) your Denon is NOT set to force the signal it receives into a 2 channel output (my Denon can do that, it's just a button on the remote you can press ...) [and it remembers the last used setting for every individual input channel separately]

Then I'd take another look at your audio midi setup utility.

Here's a few screenshots of a mac mini connected to a Denon AVR-X6400H:
View attachment 895899
View attachment 895900

This one works, and no that's not the default setting as that messed up which signals go to where.

 

[flygbuss]

If you are 100% sure (I'm not convinced) your Denon is NOT set to force the signal it receives into a 2 channel output (my Denon can do that, it's just a button on the remote you can press ...) [and it remembers the last used setting for every individual input channel separately]

Then I'd take another look at your audio midi setup utility.

Here's a few screenshots of a mac mini connected to a Denon AVR-X6400H:
View attachment 895899
View attachment 895900

This one works, and no that's not the default setting as that messed up which signals go to where.

Maybe I'm mistaken but isn't @chfilm's issue with a 2ch (stereo) source?

 

[chfilm]

Maybe I'm mistaken but isn't @chfilm's issue with a 2ch (stereo) source?

It is!

 

[MarciaFunebre]

I think one issue is it’s a digital signal. Adapters, cables... won’t make a difference.

I respectfully disagree. HDMI communicates by identifying and matching up EDID codes from the sending and receiving device. These EDID codes do not always match up because the HDMI is poorly engineered and as result the implementation of it within various devices can be end up appearing faulty.

In many cases you may be lucky but then again there are cases where it just does not work correctly. I have a SACD player by Sony which also does not work with my processor. Other components do. My Old Mac Pro does not, but my new 7,1 does. I went over that with several tech support people to confirm this general HDMI issue.

In case of an EDID mismatch you can get something like the Gefen HDMI Detective plus which will be able to pair up mismatching EDID information. I did this and the problem went away. Not happy that I had to go such a route but at least I was able to move on.