Is it True Can't Use Keyboard Controls w/ Optical Out?

Discussion in 'Mac Pro' started by gfhoward, Dec 6, 2009.

  1. gfhoward macrumors member

    Oct 6, 2009
    Is it true the optical audio out doesn't respond to the keyboard audio controls? I read that the tosslink out volume cannot be adjusted using the keyboard controls. Can anyone confirm? Thanks
  2. thegoldenmackid macrumors 604


    Dec 29, 2006
    dallas, texas
    My Logitech diNovo Edge Mac Edition controls volume fine? I see no reason why this wouldn't be the case, tis seems fairly basic. Want to link us to an article that mentions this?
  3. akm3 macrumors 68020

    Nov 15, 2007
    OS X Can't control the volume on an optical out. It is an OS X limitation not a keyboard issue.

    It always puts it at full volume and expects you to control volume in whatever you are sending it out to...which sucks.
  4. H0M3R macrumors member

    Oct 16, 2007
    I have a 2006 Mac Pro connected to some Logitech Z-5500 speakers through optical. Its true under OS X you can not control the volume or even mute the speakers using the keyboard. However it works fine under boot camp.
  5. J the Ninja macrumors 68000

    Jul 14, 2008
    Windows SHOULD work this way, but it doesn't. You're best off setting the volume to full up on Windows, and just leaving it that way and adjusting from the audio processor. All it is doing is modifying the signal to pad it down instead of passing it as-is. This is true of ANY computer digital out.

    P.S. Set your iTunes volume control to full-up too.
  6. Icaras macrumors 603


    Mar 18, 2008
    California, United States
    Yes, it's true. You don't just lose hardware support, you lose software support for controlling volume. Everything will have to be controlled via your Z-5500 Control Module or Logitech remote.
  7. akm3 macrumors 68020

    Nov 15, 2007
    You dont' always have easy access to whatever is receiving the signal digitally. it would be nice to have the option to adjust it.

    Example, I have som Roland DS-50A studio monitors, the volume controls are a knob on the back. I have to reach around behind EACH speaker to adjust the volume, independantly. This sucks.

    So I just run analog so I can control volume in OS X.

    OS X should work like windows on this one, not the other way around.
  8. J the Ninja macrumors 68000

    Jul 14, 2008
    Studio monitors are generally fed from an interface, whose analog out level can be varied from within the OS. Software volume controls are great for analog outs, and I am all for them.

    Digital outs are another matter, however. With these, volume controls do nothing good, at all. You are mucking with the bitstream because you didn't put your audio pre/pro somewhere useful, or buy one with a remote. It's a detrimental convenience feature, nothing more. Adjust the signal ONCE, at the end of the chain. That means set your digital out to full-up, and leave it there. So Core Audio does it for you.
  9. pagupagu macrumors newbie

    Jan 7, 2010
    Question : is it possible to adjust optical/numerical output volume ? Answer : Yes

    Waiting that Steve eventually add the missing "vol/mute unlock" option in the optical setting pannel, it is possible to use the optical output by getting soundflower (freeware)

    Why Apple disabled vol adjustment on numerical output ? In my opinion it is a "design bug" and I can't understand this "techno-ideological" decision wich is VERY unconvenient for most of Mac users, making their optical output just a useless illuminated plug. But, ok, I agree that the logic Pro and so users doesn't need to adjust its volume... How much they represent ? 0,5% ? 1% ? 2% or even 5% of the whole Mac users ? And what about the others ?

    About quality issues.
    In fact if you adjust your D/A converter and/or power amp sensitivity in order to use the full range of the Mac keyboard volume adjustment, you will get an optimum sound quality, far better than what the poor (compared to pro D/A converters) analog onboard D/A convertors can give you. The audiophile using a high-end amplifier with a 120dB or so s/n ratio will just have to set the optical/numerical output to 24/96 (via Soundflower) to get the full quality of his audio system.

    The good news is that there is a way to enjoy both optical quality AND Apple keyboard vol adjustment and mute. That is great :)
  10. TheStrudel macrumors 65816


    Jan 5, 2008
    It's not a design bug, it's working as intended. The (reasonable) idea is that you control volume from your amplifier, receiver, mixer, or dedicated sound device that your computer is connected to via optical. Most of these have accessible controls or remote controls, and if you're using one, you really oughtn't be using your computer for the volume. Pretty sure this is predicated on what audio people actually do. See J the Ninja's comments.
  11. pagupagu macrumors newbie

    Jan 7, 2010
    @TheStrudel :
    If the question had been "why isn't it possible to control sound level on the optical link output of my Mac ?" your answer (and J The Ninja one, etc.) "because it's impossible", would have been absolutely correct.

    But in fact the question was : "is it possible to control sound level on the optical link output from my Mac ?"

    And the answer to this question is definitely YES.

    You just need to download a tiny 500 KB freeware called Soundflower.

    Then you will be able you use your apple remote to control the optical output volume from your sofa exactly the same way you control the analog mini-jack output. And the mute/vol-/+ keys (F10-F11-F12) will also work.

    My last post was giving this trick and btw explaining how to reach top quality (typ. >100dB s/n ratio) on a level controled optical output link.

    I hope this will help unreasonable Mac users.

    Then you reasonable one, you never red that post, you never heared about Soundflower, keep on turning the knob or playing with analog output, and never forget : optical output level can't be adjusted ! optical output level can't be adjusted ! optical output level can't be adjusted ! :)
  12. TheStrudel macrumors 65816


    Jan 5, 2008
    Check again. I read your post:

    I wrote, and say again, it is working as intended. You are modifying it with that utility. If I had answered that it was impossible, I would then have been inaccurate (is english your first language??).

    The intention behind the software stack for audio is that the user will control audio from their dedicated audio device when using the optical output.

    I never said it wasn't possible, just that you are expected to use the audio hardware you paid extra money for. It's the user's prerogative to override OS settings. While some are well designed, others are not. This particular one is not a problem for most people and so they use it as designed.

    I would like to see some substantiation, such as an article or explanation behind your signal/noise ratio "top quality" comment, as this is the first I've even heard of it in this context.
  13. pagupagu macrumors newbie

    Jan 7, 2010
    All right, I was joking because this Toslink level adjustment is massively asked for on the Internet by many users who want to get their Apple remote working on a, Motu, Apogee, RME, etc. D/A converter but they always obtain empty replies like "it intended not to work" etc. They don't care that "it intended not to", they just want their audio investment just being usable without running across the room to turn knobs...
    I understand very well that someone who have got a high quality sound system want to get the volume adjusted via kb or Apple remote. I now this problem because my power amp is two rooms far from my sofa ! I simply can't adjust the volume from there because I do not hear what is going on in the living ! As I use a Crown Macro Reference amp (2 x 1500 W, 120 dB s/n, Damping Factor 20.000) and a pair of 4343 JBL Pro Studio Monitor (4 ways, 106 kg each) I didn't want to listen music on a cheap chipset with a 90dB signal/noise (s/n) ratio for the only reason my Mac is not able to control the toslink level from keyboard or remote, that is completely crazy ! I also didn't want to switch to Windows (whatever the toslink is well handeld and good utilities are available).

    So, each time I surf the Internet and see someone who ask this question and get this empty "techno-ideological" speech ("Toslink is not adjustable", "You must not adjust it", and so) as an answer instead of the waited for solution, I post a simple and "operative" way to help him get rid of that :)

    If you want to get some details about s/n ratio, dynamic range, overhead, and so on, you can have a look to Bob Katz "Mastering Audio" (easy to read, IMO the best for catching the state of the art in sound). You will also find some pdf litterature from Katz on the net.
    Briefly, the point in sound is to keep the signal far from noise and below clipping. That is easy if you set your toslink at 24/96 because in nearly any case you will get a range that will widely exceed (by several hundreds) the specs of a "good amp" (about 100 dB s/n). That is not true for the analog output, badly affected by the electromagnetic pollution of the environment (motherboards, chipsets, network adapters and graphic cards). This is why some users seek to use optical link at high rates that can carry a mathematically perfect signal to the D/A converter (far from any noisy motherboard, and near by the power amp input XLR).

    English is not my 1st language ! How did you get it !? :)))
  14. TheStrudel macrumors 65816


    Jan 5, 2008
    Oh, okay. You were talking about a reason to use optical instead of analog. We can definitely agree that an optical connection is always the superior option. It's just designed the way it is since most new amps/receivers or systems with an optical port also have nifty remote controls. People with older equipment are more likely to run into your particular problem.
  15. akm3 macrumors 68020

    Nov 15, 2007
    Thanks for the soundflower tip! This fixed my particular equipment difficulties and allowed me to use my digital output.


    I realize it was an intentional design decision. I even realize the purpose of it. In my case though, it meant I couldn't run digital. So, in my case, it's lame.
  16. hyram macrumors regular

    Jun 15, 2009
    Thanks for the tip!

    FYI... Audio via firewire cannot be adjusted by the keyboard either. Looking at soundflower looks like it should work, I just can't figure out how to do it. I'm not near my mp right now so can just "give it a try".
  17. goMac macrumors 603

    Apr 15, 2004
    Volume doesn't really make as much sense for optical, in since it's transmitting raw audio data. Generally you adjust the audio at whatever the last digital source is before the receivers.

    It's kind of like changing the volume of an MP3 file. You can do it, but you're going to have to alter the file and likely degrade the audio. Same reason devices you plug into your TV don't have their own volume controls. You'll notice the XBox 360 doesn't have it's own volume control.
  18. akm3 macrumors 68020

    Nov 15, 2007
    Yes yes, we covered all that and I agree, however, some 'last digital sources' ARE the Mac. And you can't adjust the volume. Which sucks.

    Or, the last digital receiver doesn't have convenient volume control (like the knobs are on the back of the speakers...and in my case each speaker has it's own knob you'd have to reach around behind AND adjust each one independantly. . . that sucks too)
  19. ncc1701d macrumors 6502

    Mar 30, 2008
    I really should ask more questions here :) I recently switched to optical and just made do with the inconvenience of leaning forward about a foot to adjust the sound ;) I was going to look for the remote for the amp I've hooked it up to, but that sounds like hard work too :D I love soundflower!!
  20. goMac macrumors 603

    Apr 15, 2004
    Proper audio receivers are getting pretty cheap. A proper DTS/Dolby receiver could probably be found for ~$100 on Craigslist or ~$200 new. It won't have nice HDMI scaling or anything, but you don't need that for audio. Might be more bulky, but it would certainly work better. :)
  21. nightfly13 macrumors 6502a


    Jul 17, 2008
    Ranchi, India
    Sunflower usage?

    I've also asked this question (even here on MR) and am excited to hear this response. I can not, however, get it working right.... or at all.

    The two apps I'd like to be able to control the volume from the keyboard/remote are iTunes and VLC. When I enable Sunflower (2CH) as the output sound device in system preferences, it's silent. I can't manually set it in iTunes. In VLC, I can choose sound device, but again, nothing seems to work (regardless of which output devices is selected in 'sound').

    Further, 70% of my VLC usage is with 5.1 encoded audio (Dolby Digital/DTS) - will Sunflower be able to handle that?

    I'm using a HT receiver. I feel like I should be able to figure this out, but the instructions on the Sunflower page seemed to be aimed at sending a signal from one app to another, which isn't what I want to do. I'd love to be able to control volume on 5.1 streams with the same single remote that I play/pause with.
  22. cynikal macrumors member

    Aug 12, 2003
    i wish someone would figure out how to be able to remap the volume functionality on the keyboard to being sent to just itunes or vlc (whatever app is in front).

    didn't macs behave at this for a little while a long time ago? I'm not sure, someone mentioned it on another forum/thread.

    i downloaded the logitech control center drivers, and looked through system preferences keyboard section, no where do i see any way to control how the volume keys function. what plist or whatever do i have to edit, damn it.. i refuse to just give up the use of the volume buttons/slider on the dinovo edge mac edition keyboard, and i don't want to mess with sunflower cuz i have DTS music that HAS to have unmodified optical signal.
  23. ActionableMango macrumors G3


    Sep 21, 2010
    I'm not able to adjust optical audio volume nor HDMI audio volume with my Windows 7 PC. Maybe it depends on which audio device and drivers you are using. My only control option for optical audio in Windows is to Mute or not.
  24. krravi macrumors 65816

    Nov 30, 2010
    So if there is no way to control the volume using software when using SPDIF, then how come the volume slider in iTunes works?
  25. cynikal macrumors member

    Aug 12, 2003
    it works because itunes is modifying the sound data ("deamplifying" it) before it goes out the SPDIF. Try doing that while playing a DTS or DDS soundtrack is playing and it'll turn to white noise. The system is set up to normally send audio digitally in unmodified format (at least by the global settings).

    But what i wanted was just to have the keyboard instead of having the volume slider on the keyboard control the global sound (which when SPDIF is connected, is not a valid action), have that volume slider be sent to the app in front focus (typically iTunes on my HTMINI). Since i am connected via SPDIF, when i'm listening to regular 2.1 music, i want that volume slider to control iTunes. But then again i guess i want too much :-\ Kickass keyboard though otherwise

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