Automation and Summing OTB

Discussion in 'Analog Summing' started by unconsenting, Jul 10, 2010.

  1. unconsenting

    unconsenting Guest

    I have been looking for a mixer that covers a need of many of us. I'm talking about using a mixer for its analog summing without just setting the faders to unity and automating in the computer. I have used SSL and AMEK mixers with their own automation engines and recall systems, but we all know how much they cost. I have a concept idea that seems simple to me but maybe this community can chime in. Here's the idea:

    A mixer with motorized faders that are controlled by the DAW but actually control the audio level of that analog channel. Let me use it in an example.

    I have a lead guitar track on track 10 in the DAW that will need volume automation throughout the song. I route aux 1 PRE FADER out analog output 10 to line input 10 on the mixer. This allows a strong signal out of the computer that WILL NOT be affected by its DAW fader. Then, fader 10 on the analog mixer, which is motorized, will control the fader of track 10 in the DAW. So, I write the automation to the DAW and when it plays back, it controls the physical fader on the analog mixer which sums it with the other tracks in the analog mixer to its stereo bus.

    I hope I explained this well. Basically, the idea is to have an analog, automatable mixer that is driven by your DAW. Here's its quick signal flow during mixing:

    In the DAW- goes through its processing like plugins, etc. Pre fader aux routed out the soundcard.
    In the analog mixer- soundcard output routed or patched to an input on the mixer. Outboard gear can be inserted, mixer's eq can be used and sent to the channel's VCA fader. This fader is controlled by the automation of the DAW which did not affect the source in the computer but is now controlling the volume in the analog mixer.

    Does this make sense?
     
  2. Boswell

    Boswell Moderator Distinguished Member

    In a word, no.

    It's not clear what you are trying to achieve with the patching and routing you describe. Are you attempting to use the amplitude of a recorded signal on one track to control the level of another? Do you want to make sure the channel signals actually go through the faders and avoid the use of VCAs?

    If you want a real analog mixer with real motorised faders, you either have to pay the going price for a commercial one, or, if you have the skills, build one yourself. However, you don't have to go all the way up to an SSL or Amek to get them - the new A+H GS-R24 has them as an option and comes in at a fraction of the price of the large-format desks, and with comparable analog mix and EQ sonics.
     
  3. unconsenting

    unconsenting Guest

    The A+H mixer is a perfect example. The faders of this mixer can either adjust and sum an analog signal to its stereo bus or they can be switched to control your DAW via its motorized faders but not both at the same time. I'm proposing that the volume automation of the DAW drive the faders in their analog mode rather than just their midi controller mode. The fader can sum a signal like an analog mixer and also has a motor to drive it as a controller; why can't it do both at the same time like a large format console can. I don't know any other way to explain this.
     
  4. unconsenting

    unconsenting Guest

    I'm sure all here understand the advantage of analog summing of digital audio. Currently the only affordable, repeatable option for this is to set your analog mixer to unity and adjust the levels of the source in your DAW. That way, if you close your project, zero out the board, and re-open the project, all the routing and automation is set in the DAW project and you just set all the faders to unity. Some summing mixers (like TL Audio's A4) do not have level adjustment and require you to adjust the levels in your DAW. The issue I see here is quantization error of low level signals coming out of your sound card. So ideally, you would want a strong, un-attenuated signal coming out your sound card and adjust its level in the analog world. But then you must write down every setting of every fader, which is time consuming and never exact. The only mixers THAT I KNOW OF that can do this have their own computers with recall software and are expensive. Why not use the DAW to recall these settings? Use the DAWs automated faders to drive the motorized faders of the analog mixer, which then controls the level of the audio passing through that analog channel?
     
  5. Boswell

    Boswell Moderator Distinguished Member

    I'm sure you have this all clear in your head, but the posts are reading as though automation is being conflated with control surface operation.

    If I understand you correctly, what you are asking for is straightforward automation, where a track (usually MIDI) in your DAW controls the position of the faders on a true analog mixing board. The DAW faders are all set at 0dB and the signals are output unattenuated through multi-channel D-A converters to the line inputs of the mixing desk. The desk's faders determine the balance of the mix, and the resulting two-track mix can be digitized by the same DAW, or by a separate capture device or written to tape. Some mixing desks have built-in D-A and A-D conversion, and all the data transfer (bi-directional digital audio plus MIDI) is sent down a single FireWire cable.

    Control surface operation has desk's faders used as parameter generators, and the MIDI control signals go the other way (into the computer) to control the virtual faders in the DAW. This mode of operation does not seem to be called for in what you describe.

    I don't know if you have been fortunate enough to inspect the new A+H GS-R24 that I mentioned earlier, but it has the option of motorised faders, and, as far as I can tell from the pre-release information, can be used in exactly the way I decribed for automation.
     
  6. unconsenting

    unconsenting Guest

    Yeah unfortunately, it is only very clear in my head. Even when I read my posts, I confuse myself. It seems like you understand though. I know it seems like I am confusing the modes of operation of a mixer like the GS R24 but Im merely wondering if another mode could be added. I have not been privileged with seeing the GS R24 in person, but if it is like the R16, when you switch a fader to midi control mode the analog part of the fader defaults to unity. So Im assuming that when you switch to control surface mode on the R24, the analog part of the fader defaults to unity, also. I was just figuring if on the GS R24 the fader has both the ability to be motorized in midi mode and adjust volume level in analog mode, why it couldn't be combined; use the motors to control the volume of that fader. Sorry for the confusion.
     
  7. Boswell

    Boswell Moderator Distinguished Member

    Well, the actual control of the fader positions in real-time can all be done via automation from a MIDI track in the DAW. The problem that you are trying to express may be that of how to generate and subsequently modify the automation track.

    If this were a digital mixer, you could capture the MIDI control stream from the mixer while manually operating the faders during the first mix. Subsequent mixes would use that MIDI track in automation mode, reproducing exactly what you did first time around, until you used a MIDI editor to change the automation track. However, in a digital mixer, the faders are only ever parameter generators and never handle signals, so it is easy to set it up so manual changes in the fader positions are signalled in the MIDI output stream.

    Non-VCA analog mixers have to use a mode switch (globally or per fader) to say whether a fader has signal running through it, or the fader by-passed (signal at 0dB) and used as a parameter generator for control surface duties. Since this latter operation has to be done by putting a constant voltage on the top of the fader, and the ratio of the resulting wiper voltage to the end voltage used as the control parameter, the two modes cannot be run concurrently.
     
  8. unconsenting

    unconsenting Guest

    Wow. I did not realize that. Thank you for the explanation. I see now that it is not as easy as I thought.
     

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