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Macs and 5.1 surround sound

P

PBMB

macrumors 6502
Original poster
Mar 19, 2015
334
136
I have a 5.1 system from Logitech connected to a Macbook Pro through a Sound Blaster Omni Surround 5.1. The setup is correct because the audio test performed by the SB Omni control panel activates correctly each speaker individually. Same with the Audio MIDI Setup utility in Mac OS X: it is configured to output 5.1 sound and it activates correctly each speaker during the test.

So far so good. The problem is that when I play a movie from a DVD or iTunes, that has 5.1 sound, I have only stereo output. This affects both DVD Player and iTunes in two machines, one under Snow Leopard and one under Yosemite. I tried to open the DVD with VLC and it says that the system audio is not configured for 5.1 sound and that I have to do this through Audio MIDI Setup. But this is already configured correctly, therefore, for some reason, the Mac OS X applications fail to see the setting.

Of course if I enable SBX Pro Studio enhancements in the SB Omni control panel I have audio from all speakers but if I understand well, this is only an enhancement, a kind of simulated surround sound.

At this point I ran out of ideas. Anyone with suggestions, solutions?

Thanks!
 
Movies are usually encoded in Dolby Digital or DTS so you need a decoder for them. Does that soundblaster have it? I use a receiver, optical cable and it works flawlessly.
 
Skika said:
Movies are usually encoded in Dolby Digital or DTS so you need a decoder for them. Does that soundblaster have it? I use a receiver, optical cable and it works flawlessly.
Click to expand...
I thought this is what DVD Player and iTunes are for.
 
Which Logitech's?
Have you checked that your speakers are set for 5.1 sound (some Logitech's have it's own control console)?
Aand have you tried connecting the speakers straight to your Mac?

Pictures and screenshots from the SoundBlaster software, Apple's Midi setup and the possible control console of the speakers could be helpful to encounter the problem.
 
capuzino said:
Which Logitech's?
Have you checked that your speakers are set for 5.1 sound (some Logitech's have it's own control console)?
Aand have you tried connecting the speakers straight to your Mac?

Pictures and screenshots from the SoundBlaster software, Apple's Midi setup and the possible control console of the speakers could be helpful to encounter the problem.
Click to expand...
It is the Logitech Z506. There are no special surround setting on the speaker system, it is quite a basic one. It is sufficient to connect it to the output of an audio source.

As I wrote in the beginning, I can hear sound from each channel separately when I run the audio tests in the SB Omni control panel. Initially I had the wrong cable connections. For example, when I clicked the button to activate the back left speaker, I could hear sound from the central unit. Eventually, I figured out which are the correct cable connections.

I can see this 5.1 configuration displayed correctly also in the Audio MIDI Setup utility. Clicking the test buttons of this utility again sends the audio signal to the correct speaker. This is why I assume that the setup is correct. It is a mystery though why the applications cannot send 5.1 output. VLC is more verbose: it says that the Audio MIDI Setup has not been set for 5.1 audio, while it is and the audio test signal pass through correctly!

It is not possible though to connect such an audio system directly to a Macbook Pro. Well, it is, but only in stereo mode with one cable. For the 5.1 connection you need two more cables and a Macbook Pro does not have outputs for those. This is why a separate sound card, like the Sound Blaster is needed. By the way, the SB card takes input from the USB port.
 
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I looked up the sound card you are using and it looks like it can't decode Dolby Digital or DTS. That is why you are getting stereo only from DVDs. Only way to get sound from speakers is to use the card's surround enhanced modes.
 
z31fanatic said:
I looked up the sound card you are using and it looks like it can't decode Dolby Digital or DTS. That is why you are getting stereo only from DVDs. Only way to get sound from speakers is to use the card's surround enhanced modes.
Click to expand...
But the Dolby decoding is done in software by DVD Player or iTunes, no? I have tried DVD Player with DTS and there is not output at all, simply because it cannot decode it. But it decodes Dolby Digital since there is audio output. Am I missing something here?

Besides, the SB Omni user manual confirms that you can decode a DVD in software (it suggests PowerDVD) and then send the output to SB. So, could this mean that DVD Player and iTunes decode Dolby Digital to stereo output only?
 
PBMB said:
But the Dolby decoding is done in software by DVD Player or iTunes, no? I have tried DVD Player with DTS and there is not output at all, simply because it cannot decode it. But it decodes Dolby Digital since there is audio output. Am I missing something here?

Besides, the SB Omni user manual confirms that you can decode a DVD in software (it suggests PowerDVD) and then send the output to SB. So, could this mean that DVD Player and iTunes decode Dolby Digital to stereo output only?
Click to expand...

Try with MplayerX
 
Skika said:
Try with MplayerX
Click to expand...
Just tried it. Regarding DVD's, MplayerX is a total mess. Sometimes it won't play at all a DVD. And when it does, you cannot choose playback position nor chapters, it just picks up one arbitrarily and the audio output signal is very weak. However it activated the central speaker when this one stayed mum under DVD Player! But the rear speakers were still silent.

So this is one more indication that there is something "wrong" with the DVD Player and iTunes decoding of Dolby Digital. My guess is that those two applications send 5.1 surround through the optical output but not through USB. Can anyone confirm?
 
You might want to give this a read: http://fplanque.com/dev/mac/ac3-ac-3-5-1-surrond-sound-apple-mac-osx That's a few years old and I'm not sure it still applies. If you go to their website: http://www.perian.org it looks like they've dropped support for it ahead of OS X 10.8. But the gist of that message is that you need more than stock OS X stuff to do what you want to do here with a Mac. Maybe that changed around 10.8 and that contributed to why they quit developing perian? But my guess is that stock OS X software doesn't output 5.1 except maybe through the HDMI connection on some models. If you have a model with HDMI and your 5.1 system can receive HDMI, test that.

Else, it seems pretty plausible that DVD Player may not support 5.1 out since all Macs default to stereo (speakers).

This thread: https://forums.macrumors.com/threads/10-9-mavericks-quick-look-support-codecs-like-perian.1647722/ has people saying that Perian both works and doesn't work in OS X 10.9. So if you download the last version of Perian, that may also be a "just test it and see what happens" task.

This thread: https://forums.macrumors.com/thread...fi-and-surround-sound-on-macbook-pro.1318218/ seems very applicable to this issue. And it strongly implies OP can't accomplish what he wants unless he plays his video through VLC (and, even there, some references to it playing through the wrong speakers make me wonder if it will work (correctly) that way too).

Note: because I've upgraded OS's for several generations, I still have Perian installed. In preferences, it offers output options of Stereo, Dolby Pro Logic, Dolby Pro Logic 2, and Multi Channel Output. If I was attempting to do what you are attempting to do, I'd be selecting that last option and see what happens. But since my Mac is connected to only stereo speakers, the setting is defaulting to Dolby Pro Logic 2.

One option that will work: rip your DVDs with Handbrake and drop the result into iTunes. Get an :apple:TV and hook that to your TV. That will get you 5.1 Dolby Digital out of both your DVDs and your iTunes purchases.
 
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Does the Mac have optical out? He references Macbook Pro. I also have a MB Pro and it doesn't have an optical out jack.

I think he's connecting a 5.1 box via USB and it's not doing what he thinks it should. I suspect he needs a driver and even then, that would depend on stock DVD Player using the driver to do what he wants. I'm guessing the problem is there. This thread: https://forums.macrumors.com/thread...fi-and-surround-sound-on-macbook-pro.1318218/ seems to support that guess.
 
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correct.. use an optical audio cable.. thats how i have my Logitech Z906 connected
 
Thank you all guys for the suggestions, really appreciated.

Let me first express my big surprise to realize that Apple's own software is so limited. A company that touts itself as a leader in the audio/video department for the broad public to have this kind of limitations in their consumer software these days. Mind blowing, I am speechless. Real shame.

furbzv1 said:
correct.. use an optical audio cable.. thats how i have my Logitech Z906 connected
Click to expand...

One of the big differences between the Z906 and the Z506 is that the former has optical digital input. The Z506 is a basic system with only analog input, the well known three colored cables.

So, is there some kind of adapter to transform the optical output of the Macbook Pro into 5.1 analog signal, appropriate for a sound system like the Logitech Z506?

capuzino said:
The optical sound output is integrated to the headphone port on MBPs. You just need an 3,5mm adapter for that.
Click to expand...

See my question above. The Z506 cannot take an optical digital cable directly. Any solution to this?

So, if I understand well, and despite the fact that Creative made a good job to write Mac drivers and a control panel for the SB Omni, this device is essentially useless on a Mac to watch a movie with proper surround sound. What a bummer! Well, at least the sound is perceptibly more clear compared to the direct audio output of the Macbook Pro on the same speakers, and with the SB Pro Studio enhancements it can imitate surround sound. I noticed that the result is different from DVD to DVD, so it is not simply sending the same sound signal to each speaker.
 
Hmm, could something like that work? It is not cheap though, more than half the price I paid for the Z506!

Or this.
 
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z31fanatic said:
You connect the optical cable to the sound card. The logitech system doesn't need to have an optical output.
Click to expand...
I am afraid this is not possible. The SB Omni has an optical output, not input. It says in the user manual:

Optical S/PDIF Out Connector: Connects to the Optical In connector of recording/playback devices with optical connectors (for exam- ple, MiniDisc recorders, Digital Audio Tape recorders or external amplifiers).

This is what I understand from this description.
 
The problem is that both iTunes and DVD player will only output 5.1 via optical or HDMI. You should however be able to get it working with VLC so I'm not sure what is going on there.
I'm wondering if there is some conflict between the SB control panel and Audio MIDI set up. I would be tempted to uninstall the SB control panel and see if that lets VLC play nice.
I'm assuming that you have checked the obvious and that when trying to use VLC that you have selected the SB as the audio output device, both within VLC and via option clicking the audio settings in the menu bar.
 
z31fanatic said:
What does that card even do then? It seems worthless to me.
Click to expand...
Yes, this is more or less what I wrote previously:

So, if I understand well, and despite the fact that Creative made a good job to write Mac drivers and a control panel for the SB Omni, this device is essentially useless on a Mac to watch a movie with proper surround sound. What a bummer! Well, at least the sound is perceptibly more clear compared to the direct audio output of the Macbook Pro on the same speakers, and with the SB Pro Studio enhancements it can imitate surround sound. I noticed that the result is different from DVD to DVD, so it is not simply sending the same sound signal to each speaker.

From my experience this is all you can have from the SB Omni on a Mac for movie playback, with the drivers and the control panel: a more clear sound, stereo or simulated surround. I repeated it so that other users in the same situation don't miss it. It is a really important point for someone to decide if this card can serve his needs or not.

But it is not entirely Creative's fault here, because the card can redirect 5.1 surround sound (one sees this by testing the setup with the built-in utilities; all speakers can receive independently audio signals). Apple seems to be the other player at fault since, according to the evidence so far, the DVD Player and iTunes do not send 5.1 surround over USB, they send only stereo audio.
 
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In the meantime I found this adapter. Expensive (for an converter), but it seems on paper that this is what I am looking for. Plus, it has USB output, so it could(?) be used in conjunction with the SB Omni in order to benefit from the SBX Pro Studio enhancements. Anyone with experience with this device or similar?
 
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