Simplest matrix control to USB for ZED 428

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This topic contains 7 replies, has 3 voices, and was last updated by Profile photo of Mike C Mike C 2 months, 1 week ago.

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  • #98490
    Profile photo of DaPo
    DaPo
    Participant

    We’ve used our ZED 428 to reinforce sound in our church building, but now we’re sending out to Zoom users also via a computer on the USB output.
    I’m the organist – not an audio tech – but did some reading to try and get decent level for my instrument.
    The pipe organ doesn’t need a mic for ‘the house’ – it already fills the room – but it is necessary for the broadcast feed.

    I figured that using the Matrix was the smartest way to allow levels to be controlled.
    Three vocal mics on various channels are assigned to the main L-R (left-right) bus.
    I have set up a condenser mic for the organ on channel 7 as the sole user of the route marked “1-2”.
    My understanding is that the operator can work the faders for the mics and achieve a relative mix that will work for both destinations – ‘house’ and broadcast Zoom transmission via USB. The organ can be mixed in solely to the USB mix using the matrix along with its channel strip.

    My question is how to make this work simply. Apart from the “M” bus, everything seems to be set up for potential stereo use. As things stand, I’m faced with possibly four controls to alter where I’d prefer one.

    You can refer to the help sheet I drew up (Zoom and the Matrix.jpg). My note in green is the key question here: “It MAY be possible to use fewer knobs and still get strong output – we’ll look into that!” The two matrix outputs are *both* sent to the USB output (MTX 1-2); you can’t select just one of them. And most of the channels are prefigured as pairs. If I take a naive approach, with all Pan controls at 12 o’clock, then I might have four matrix controls to manipulate for each group. In my help sheet, I’ve suggested that if we need more organ in the mix, we manipulate the Group 1 / Matrix 1 level, then match it for the other three combinations of (Group 1 or 2) * (Matrix 1 or 2).

    I guess I could use the Mono (M) bus for the organ ‘group’? In that case, we’d have only the Matrix 1 * Matrix 2 duality to deal with. Is it true that to get maximum signal to the computer, I would need to duplicate my Matrix 1 setting for each channel to the Matrix 2 column? Or is it less a sum than a ratio? (If Matrix 2 levels are all set to zero [or whatever], will Matrix 1 supply the full available signal bandwidth to the USB interface?)

    I’m interested in pursuing my understanding of the paired channels thing, so let’s say we stay with the current assignment of the organ to channels “1-2”. (In any case, I suppose this applies to the main “L-R” feed.)

    First, I understand that “1-2” is managed via Pan. If I want to use only one of channels 1 and 2, I could Pan the control all the way to one side. I had a kind of success here, but found that I concentrated signal by panning Channel 7 all the way to the *right* (which is marked “Even”). I thought that the underlying design for left-right output had to do with oddness or evenness of the channel numbers – am I wrong here? Once again, do I help things by panning thus – does this actually deliver the same total signal to the USB destination via the matrix than if I’d had the Pan set to 12 o’clock and the Group “2” levels in the matrix matched?

    We don’t actually use stereo in the house with our L-R setup. I think all the mics are Panned to 12 o’clock. Does that mean I must attend to Matrix 2 on the assumption that there’s an “L-R” stereo signal being sent to the USB via MTX1-2?

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    #98493
    Profile photo of DaPo
    DaPo
    Participant

    (Sorry: that was my first post here. Assuming I can’t edit my post, some corrections on my terms:)
    I’ve used “channels” a few times where I meant “groups”.
    The “paired groups thing”.
    Panning as I understand it will deliver signal in the assigned relative proportion to Group “1” or “2”, for example, in the same way as it would to “left””and “right”. I think my counter-intuitive discovery was that Group 1 signal improved when I panned the contributing channel Right (“Even”) rather than Left (“Odd”). Which is odd!

    #98496
    Profile photo of volounteer
    volounteer
    Participant

    @DaPo

    House and zoom would likely need different mixes. Also broadcast if you mean AM/FM or real TV.
    Matrix could work depending what you are feeding into it. I think an aux might work better.

    Why use zoom instead of livestream to utoob or facebook like most seem to do?
    example https://www.youtube.com/watch?v=JvEpf9zH1vs

    Tried to check the documents for more but the pdfs are not flattened and wont scroll on my pc.

    #98499
    Profile photo of Mike C
    Mike C
    Participant

    You ultimately need to create two different mixes, one for the main PA system and one for the live stream mix.
    There are a few ways to get there with the mixer you have but you said simplest….
    Your somewhat close but I think I can take out a couple routing steps.

    It sounds like your already using the USB connection to send to the computer.
    The matrix and the mono mix option for the organ mics and anything else you only want
    to send to the live stream out will work.

    -make sure the only USB source button pushed is MTX1-2.

    -in the matrix mix turn up the L R and M to the unity gain mark with the
    other inputs levels turned down. Turn up the matrix main levels as needed.

    -on every input channel that you want to go to both the PA system and to the live stream assign those channels to only the LR mix, the assign buttons are next to the channel faders.

    -on the channels that you only want to go to the live stream assign those channels only to the M mix.

    That set up will get your two separate input sources mixed together for the live stream.
    You can use the matrix AFL buttons to monitor the audio going to the live stream with headphones plugged into the mixer.

    If you want to use groups…..

    The group function works like you found out, when a channel is assigned to a group the pan knob left right rotation will select group 1 or 3 to the left, 2 or 4 to the right.

    If your are using groups already like for instance all the vocal mics are assigned to group 1 and all the instrument inputs are assigned to group 2 you’ll need to check a couple things.
    -any channels that are using a group assignment you want to check that they are not
    assigned to the LR or M output mixes.

    -at the top of the group master section there output mix assignment buttons,
    group assigned channels you want to go to both the main PA and live stream
    you want that group assigned to the LR.

    -group assigned channels that you only want to go to the live stream you want that
    group assigned to the M output mix.

    For your Zoom broadcast are you receiving incoming audio from the viewers?

    A couple churches I set up with 436 ZED’s use the USB with the matrix about like your wanting to do, one does it for recording to a PC and the other for live streaming.

    #99594
    Profile photo of DaPo
    DaPo
    Participant

    Mike_C, thanks so much for that really thorough and complete-sounding advice – and sorry that I’m so late reading this.
    I was relying on the “Notify me of follow-up replies by email” feature of this forum. (If it did that, I didn’t see it.)

    I see then from your advice that it’s OK to use the “M” mono output mix for our Zoom-only livestream.
    That rids us of worrying about the odds-and-evens thing with the numbered groups.
    Thanks, though, for covering that contingency, too, which we can remember if groups get used in the way you describe.

    My remaining question with the Matrix (on the ZED-428 anyway) is the other pairing that we’re dealing with: the USB output is preconfigured to accept both Matrix “vectors” I guess – both 1 and 2: “MTX1-2”. At present, I’m advising that we pump signal through both column 1 and column 2. Whatever we do with the knobs in the first column of the matrix, we copy to the second. I’m assuming that the signals are simply summed together. If, instead, the available signal output is allocated by proportion, we could just ignore, say, column 2 altogether (maybe set its master level to zero) and concentrate on level-setting in the first column. Do you have any opinion to offer here?

    Yes, we’re receiving incoming audio from the viewers – that’s one reason why we’re Zooming rather than simply one-way livestreaming. On this point, we seem to have a duality. We can receive the USB input as “Playback to LR“, or we can have it come in as ST3 (if I recall the identifier correctly). We seem to have got more sound by using the former. There is more control (via fader, etc.) using the latter, coming through the channel strip. We’ve often got both of them active – ‘belt and braces’ – but that’s not good when you want to control things – e.g., to mute. Two places to look. Is there a best practice here?

    I promise to visit this page again this weekend and/or soon after, and not rely on email notifications! 🙂

    #99595
    Profile photo of DaPo
    DaPo
    Participant

    Hi, volounteer – sorry I was so slow getting to see your reply.

    We may yet also livestream on a conventional service, but we use Zoom for two-way interaction. Some participants are remotely located. We see them on a projected screen, and sometimes hear from them through the church’s PA, controlled of course via the ZED-428.

    I liked the idea of the matrix rather than a complete reworking via an AUX, because we’ve got just one operator.
    If the mix of voices is right for the ‘house’, we’re happy for those relative levels to serve for Zoom as well.
    But for the external delivery, we need to capture the ambient sounds that usually go ‘un-micd’ in the building – principally the pipe organ – which vocal mics won’t do well.
    If we use the matrix, we can mix in the organ to the already-established voice mix.
    In other circumstances – with two experienced audio techs – perhaps in different rooms – I agree that porting all the sounds might be the way to go.

    #99598
    Profile photo of volounteer
    volounteer
    Participant

    @DaPo

    email only happens when someone sends you a private response
    always check the main board for answers to your posts

    Unclear why you use the zoom folks on a screen.
    I do not know of any churches using zoom like that in the states.
    Most use streaming to utoob or similar. or they use zoom for other purposes.

    We have to change our mix slightly for livestream. Zoom could be the same.
    The video team could do it in OBS at their pc but it is easier for them to have us tweak it before we send it to them.
    As to ambient for the organ, we use two of the choir mikes with the faders down a bit in the mix,
    to capture the organ which is very loud acoustically and unmiked. We do use a Qu which is slightly different from the Z428

    We also have CD and PC playback at times, and the sound from those goes to the video mix too, again with levels they like.

    Like MikeC said the levels will be different live and for the video users.

    #99601
    Profile photo of Mike C
    Mike C
    Participant

    My remaining question with the Matrix (on the ZED-428 anyway) is the other pairing that we’re dealing with: the USB output is preconfigured to accept both Matrix “vectors” I guess – both 1 and 2: “MTX1-2”. At present, I’m advising that we pump signal through both column 1 and column 2. Whatever we do with the knobs in the first column of the matrix, we copy to the second. I’m assuming that the signals are simply summed together. If, instead, the available signal output is allocated by proportion, we could just ignore, say, column 2 altogether (maybe set its master level to zero) and concentrate on level-setting in the first column. Do you have any opinion to offer here?

    Yes, we’re receiving incoming audio from the viewers – that’s one reason why we’re Zooming rather than simply one-way livestreaming. On this point, we seem to have a duality. We can receive the USB input as “Playback to LR“, or we can have it come in as ST3 (if I recall the identifier correctly). We seem to have got more sound by using the former. There is more control (via fader, etc.) using the latter, coming through the channel strip. We’ve often got both of them active – ‘belt and braces’ – but that’s not good when you want to control things – e.g., to mute. Two places to look. Is there a best practice here?

    The two matrix channels are independent on the USB audio feed, for streaming broadcast that are looking for a stereo audio feed if you only have audio content on matrix 1 anyone listening with a stereo audio system or headphones would only hear audio on one speaker. I would set each matrix the same.

    For the incoming audio I would just use the ST3 input, be sure to check that the ST3 routing button is set to ch/channel so you have the full channel strip control.

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