How can I control my Audio output from iOS?

I want to sample youtube from my iPad through my iCA4+. But I can't use the volume buttons and there's no option to control the output gain from my iPad from iConfig neither from MacBook or iPad.

How come?


  • You don't need to change gain. It's a straight digital signal copied from one device to another.

    If you use Auracle it will automatically route your iPad output straight into your MacBook. From the Auracle User Guide:
    • In your iPad audio will normally be automatically directed from your app to your iConnectivity interface. If it does give you a choice of audio outputs pick USB1 1&2
    • In your DAW, create a new stereo audio track
    • If you are using an iConnectAUDIO2+ set the track’s audio input to be Inputs 3&4
    • If you are using an iConnectAUDIO4+ set the track’s audio input to be Inputs 5&6
    Now just hit Record.

    Once you have finished recording, adjust the playback level to suit.
  • edited April 2018
    well, seems that some apps come with a overloud master out. I would like to change the MASTER OUT (USB1 1&2) from iPad so I don't need to adjust every preset. Totally contra producing.

    Again you're trying to teach me what I need or don't instead of just saying "our product doesn't do that".

  • well, seems that some apps come with a overloud master out

    I'm not sure what you mean by "overloud". If they are producing a digital out, then the absolute maximum output is 0db. It isn't physically possible to produce a digital signal louder than that.
  • I think a lot of this confusion comes from a misunderstanding of how digital audio works. Here's a very simplified guide:

    The maximum amplitude (volume) of a digital signal is 0db, or Full Scale. To reduce the "volume" of a purely digital signal we basically throw away bits: -6db is -1 bit of resolution. This is why DAWs operate at 32-bit floating point internally (which gives you literally millions of bits of resolution), so that if we have to throw away bits during mixing, we still have plenty left over to produce a high resolution final 16-bit output.

    However if you are going from the stereo out of one application to the stereo in of another you will probably be transferring a 16-bit fixed point signal. So if you reduce the "volume" before the transfer takes place, you will lose significant resolution. For example, if you reduced the volume to -18db you would effectively only be sending 13 bits of sound data instead of 16 bits. That's why it is generally bad practice to reduce the volume in the situation you describe. Best practice is to send the signal as 16-bit Full Scale, and then reduce the monitor volume later inside your mixer, where you have bits to spare. That way you preserve the sound quality all the way through the process.

    It's important to remember that this isn't an analog signal - you aren't actually sending "audio" from one place to another, even though that's what it seems like. What you are really doing is copying bits of data from one program to another. It's like if you copied a picture from your camera to your hard disk. Lowering the "volume" of your signal as you suggest is like saving the picture at a lower resolution. It will still be the same picture, but it will be fuzzier because it contains less information.
  • wow, now that's a good response. thanks!
    I just read it now and didn't get everything, but will read more about this subject.

    In a more non technical words, my situation is: some apps seems to deliver a signal that clips inside my DAW. When I change the preset, the Output volume back to be a a little bit overloud... What I wanted was to control the output from the Audio (whatever kind it was lol) from the DAC. Now I got it is not good for the resolution. I accept suggestion on what to do...
  • some apps seems to deliver a signal that clips inside my DAW

    That shouldn't be possible. Sending digital audio from one app to another is basically just copying a file in real time.

    What I wanted was to control the output from the Audio (whatever kind it was lol) from the DAC.

    If you are sending digital audio from one app to another then you will never use the DAC during the copy. The DAC only controls the analog signal you hear at the end.

  • edited June 2018
    The issue here is the clock. One must be the master, which is useless when two iDevices insist on being master. This is why ASRC at a single rate (say 173kHz) should have been used as the sample rate for ALL data within the iC devices, then decimated to the desired output.

    Secondly, Rodney's previous statement about digital levels is partly correct, but bad advice.

    The lower the incoming audio, the better the sound (used properly).

    Here's a quote from Terry Manning back in 2007- Google if you havent heard of him.

    "The stuff about "not using all the bits" approaches untrue urban myth status.

    The old enemy in the analogue world was noise.  We all learned recording techniques based upon that premise, whether we worked in the analogue world, or just learned from those who did so.

    Noise IS NOT A REAL FACTOR in digiworld.

    Keeping levels low helps almost every aspect of what people thought was bad about digital (harshness, tinniness, crunchiness, distortion).

    You could even record -40 to -50 dB down, and be better!  But -12 to -18 is great."

    Terry was right then and he's right today.

    The metering on most (all?) iC devices is done via MIDI, which is far too slow to be sufficiently accurate for I/O levels.
    So, best practice is to not even come close to an LED going red.


    PS I can back all of this with evidence, but don't have time today. Maybe tomorrow, if such evidence is demanded.

  • Actually no, he's wrong. That's a very common misconception. And it's irrelevant anyway, since the original poster was talking about moving digital audio from one device to another. And as I've pointed out ad infinitum now, that's the same as doing a straight 1 to 1 digital copy, so changing "volume" is pointless.
  • Changing volume might be pointless, but I agree it is nothing to fear or be even slightly concerned about, IF you can guarantee not a single bit is changed. That's hard for you to do if the iC device's internal resolution is fixed point, not dithered, faders aren't all at unity, jitter is non-existent and master/slave clocks are correctly set.

    Terry Manning (and countless others) are definitely not wrong about recording levels for digital.

    I'll respond further (soon) when I have more time.



  • I am aware of how common the "you should record at lower levels" myth is. Fortunately though, the laws of physics are not decided by majority vote :-)
  • Wanted to say thanks for the explanation / posts above, Rodney.  For the first time... I was able to route audio directly from my iPad music apps through the ICM4+ to my DAW.  The settings were done in iConfig 4.2.7 (am waiting for the upcoming Auracle release to make the switch).  Anyway - something about your explanations above, finally clicked with me.  I had mistakenly been routing audio out from my iPad headphone jack to my mixer input, and doing convoluted re-routing back into my DAW for recording on my Mac.  Ugh... The direct USB connection is louder, cleaner (i.e. noise is gone), etc.  A true breakthrough.  Anyway - thanks again for the posts.

  • I am aware of how common the "you should record at lower levels" myth is. Fortunately though, the laws of physics are not decided by majority vote :-)


    Yes, but neither are the facts of biology.

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