Can I plug a mixer into a mixer?

Discussion in 'Unregistered GUESTS' started by Someguy12, Feb 3, 2012.

  1. Someguy12

    Someguy12 Guest

    Hey folks,
    Quick question...Is it possible to plug a mixer into another mixer? I teach a guitar class and want to send a number of guitars to be played through the PA system. However, the people who run the sound don't have enough space to accommodate for each player getting an individual connection into their sound board. Is it possible for me to get an 8 or 12 channel mixer and plug into their own so they don't need to worry about space?
     
  2. Kapt.Krunch

    Kapt.Krunch

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    Yes, you could do that, but there are a few things to consider.

    First of all, what brand and model is the current mixer that you'll plug into? To get the best sound with least noise, it would be best, if possible, to be able to take a submix of your additional mixer directly after each channel's input trim>EQ>Level. So, the additional mixer should provide a post-EQ>post-channel level output source, possibly to an Auxiliary Out. Actually, if it has an AUX Out (or more) all you really need is post EQ to the Aux, and the output levels should be capable of being controlled by the Aux levels.

    What this will do is tap directly after that section to mix together to one (or two) channels to send to the other mixer before the signal is sent to any other circuitry in your additional mixer. This will help keep noise levels (from more circuitry) lower to the input of the main mixer, but still give you control over each channel's volume and EQ. It will submix in the AUX section. (If you want to run stereo, you could send, say, mics/guitars 1-4 thru AUX 1, and mics/guitars 5-8 thru AUX2, if available, and send it to two inputs of the other mixer, panned.) BUT, you need to definitely know the routing capabilities of the new (the additional) mixer. Some are set up differently, as far as pre-post stuff, and some will even let you switch the assignments.

    So, the mixer you will add should have at least one output capable of sending post EQ, level-controlled signals PRE-main mix section. (You can still connect amp/speakers and use it for monitoring, if you want. Auxes will just tap out, not stop the flow.) Now then, the mixer you'll go INTO will need some way to get that (those, if stereo) signals past all its preamp circuitry, and into the main mix buss. Why wouldn't you simply plug it (them) into an input channel or two? That's what the unititiated might consider first. A couple of reasons. First, you'd use up an input channel or two, leaving two fewer for the main mixer. Second, you'd be running an already pre-amped and EQ'ed signal thru another preamp and EQ section, adding noise, and possibly over-driving the channel.

    So, that's why I asked what the existing mixer is. Does it have at least one (or possibly two) main mix buss returns or insert points, which will bypass all the preamp circuity to inject it directly into the main mix? If it does, that would be ideal. Connected this way just acts like you've added more channel strips to the main mixer, and should (theoretically) give you the best signal with the least noise. I don't know the venue this will be used in, so that's why I asked about possibly two channels and stereo. I don't know what else might be going on at the same time in the main mixer while your 12(?) guitarists are flailing away, either.

    The reason I even mentioned it is that I'm imagining a bunch of guitars at one time being mixed to mono. I'm imagining all those same-range notes being mixed down to....indistinguishable mud in both speakers. I'm assuming these are acoustics, or acoustic-electrics? Anyway, the point is that even in a larger space, it might be good to have the ability to place various guitars in different speakers. All guitars have their "voice". Some are bright and zingy, some are round and smooth and even, some are just plain bass heavy. If several guitars are playing at once, they are likely doing different duties. It might help avoid a mud situation if you could direct the zingier guitars out to the left and right, the more even ones between them and the middle, and the guy holding down the rhythm bassy part right in the middle. Actually, if you have a couple of bassy ones, it might not even hurt to have them panned left and right, to keep their more-bassy frequencies from muddying up both speakers when played together. If it's a small room for the recitals, it's kind of like they are playing through a stereo. If it's a gymnasium, etc. and the speakers are by the stage at the end of the basketball court, then the audience will likely be far enough away that if you aim the speakers right, most should be able to hear both speakers adequately. If that becomes a problem, you could always add a couple more speakers and switch one pair's left and right position.

    The goal here is not necessarily to display your stereo-separation technique...it's to keep all the guitars that may be going through from walking all over each other, rendering each (and all) indistinguishable. Placing them at separate pan positions will help with that, since this speaker doesn't have to deal with those 2 guitars much, and that speaker doesn't have to deal with these two, etc. Anyway...that's why I asked. Now..we have another consideration.

    Tell us about the current situation. The mixer and the rest of the PA. Speaker models, power of the system, mixer model, and how they are currently set up in what room (type, size, material, etc). Are the speakers pole-mounted at the front, etc? Or, are they distributed around the room? basically, give all the info you can. If the speakers are basically just set up in the front, say, on poles... and the mixer is on stage near the performers...you may find advantage in just buying another similar-output powered mixer and another set of similar-type speakers. This also depends on how many guitars you have going on at once. How many DO you have playing at once? You mentioned a bunch, but we don't know if they are just plugged in pre-performance and level-set for convenience so that each can perform solo, duo, etc...or if there will be all of them playing Wild Thing at one time. It may be a combination of those. It might be just as advantageous, soundwise, if all of them are to perform at once to split them up in both pan position AND separate PAs. That way, you may have only a couple guitars fighting for speaker response through any one speaker at once. This may help retain clarity, though it will be tougher to keep track of. Shouldn't be much more difficult, though,if you have a good assignment chart to quickly identify who is going to where..and maybe even have the channels marked by writing on a strip of low-tack tape.

    For ANY of this, if you were to try to pan things, you may need someone sitting at the mixer to change pan positions according the performance. If you have a zingy guitarist panned right for a group performance, but he/she is coming up for a solo performance, it would be best to have that guitar panned back to center. If everything was running through two separate PA systems, you could simply use the channel pan control (if the PA is stereo-capable). If the submix routine is used to run one mixer to another, you may have to have someone learn to properly manipulate the Aux 1 and 2 Send level controls to get them panned back to center. It'd be a good mixing lesson for someone interested.

    You'd have to have that person presented with something of a "script". "Okay, Rog is up for a solo...pan him center", so the "script" reads "Rog, Mackie 2, CH 3 Pan C" etc., (or adjust Aux 1 and 2 equally, 3/4 way up on level control). Rog finishes. Script reads "Note! Return Rog Mackie 2 CH 3 Pan L 1/4" ...back to 1/4 Left pan (or turn down Aux 2 send level). This will immediately set Rog up for the next number he's participating in, if the performance is planned. If the entire show was planned, and each song has mixer moves, it might be good to try to figure out how to arrange the entire thing for the least possible mixer assignment changes as the show progresses, but the mixer person would have a chart of all the mixer moves to do to be ready for the quickest changes between tunes.

    There are a couple other things I could think of, but it won't do any good contemplating anything further until your current situation is laid out more fully, with respect to existing equipment and room, etc., and your intended goal...with respect to the performances (solos, duos, groups with a dozen guitars, etc.) Also, what is your projected budget. That will help with suggestions. Where is your current mixer situated? On stage, or 30-50' away in front?

    Anyway, just some considerations. You can definitely run a mixer into another as a sub-mixer. Do you need to? IS there another alternative?

    Please feel free to fill in the blanks, and the folks here will conjure up some viable options, keeping all this in mind. We can make it relatively simple and slightly adequate, or a bit more complicated, but better-sounding. It may even relatively simple, better-sounding, AND possibly within budget. We don't yet know. Fill us in, please?

    Good luck,

    Kapt.Krunch
     
    Last edited: Feb 4, 2012
  3. RemyRAD

    RemyRAD

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    I have had to frequently take another mixers input into my mixer. This is not an uncommon occurrence. The only truly problematic situation occurs when him proper gain staging happens i.e. sending a line level output to a low-level microphone input. There is 50 DB of difference there and you are guaranteed a completely blown out and unusable unlistenable distortion. So on the receiving side mixer, gain trim usually has to be pulled completely back and/or an additional input pad switch of at least 20-30-40-50 DB must be utilized on the receiving mixer. Conversely, some mixers outputs can be switched between average +4 0 DB outputs with a switch on the back of the feeding mixer that allows the +4 DB outputs to be outputting -50 DB output low-level microphone style output levels. Just pulling your output fader down doesn't do the job. That's because there will still be additional noise coming out of an amplifier/preamp output because the output level control is before the actual output amplifier. So you would be amplifying a lot of noise with very little signal. You would actually be getting 50 DB more noise. That's sort of like the difference between a robin chirping outside of your window in relationship to a 747 passing overhead at the same altitude as the robin. So you wouldn't be able to hear the robin but only the 747. Even though they both only have 2 wings and a tail. And that's what gain staging is all about. That's 747 wouldn't be a problem or, any louder than the robin if you could move it 35,000 feet higher. In fact if you were to move it to that height, you might only hear just the Robin.

    I've gained a stage. To record or not to record... that is the question.
    Mx. Remy Ann David
     
  4. Someguy12

    Someguy12 Guest

    Wooooow...that's a LOT to chew on!

    Well I'm definitely the uninitiated and most of what y'all are saying kinda flew over my head (except bits and pieces).

    Venue is a large auditorium with concrete walls. It will only be one or two songs and all 12 or so guitars will be "flailing" at the same time. They are all acoustics with pickups and acoustic electrics with maybe 1 or 2 full on electric guitars (without distortion). Also, you're right that the guitars will have different purposes with bass, lead, and some kind of harmony/fills being played.

    I'm not sure of the model mixer that I'll be plugging into but I'll confirm this weekend when I go to the venue. The model mixer I'm looking at is the Behringer-XENYX-1204USB-12-Channel-Mixer (Amazon.com: Behringer XENYX 1204USB 12-Channel Mixer: Musical Instruments)

    As for the speaker set up, there are already a number of monitors on the stage and there are two big speakers hanging from the roof angled to each side of the room at the front of the room (right between the stage and the audience). I'm sure that there are other speakers around the place but I can't picture them in my head. I'll have to make a list of stuff to confirm and I'll get back to you about those.

    1. model of main mixer
    2. model, positioning and quantity of speakers

    Looks like I have a lot to learn here!
     
  5. Unregistered

    Unregistered Guest

    Someguy...

    You'd plug an Auxiliary Out of the Behr into whatever post-preamp input your main mixer may have (That would be something like an Amp In that blends into the mixer signal, or some other input that bypasses all the channel controls). You'd want to switch the Aux Pre/Post switch to Post. That will allow the Behr EQ and Channel Volume faders to control EQ and each instruments' volume, as they will be mixed to the that Aux out, and go into the main mixer. The main mixer amp will then see one channel of premixed signals.

    That's why you want to use "Post", so the volume sliders on the Behr will be fed into the Aux buss. Otherwise you'll have only the input trims to work with. The input trims should be set to get the best signal into the Behr, not to control the output.

    One caveat. If you can find a different reputable brand of mixer with similar functionality, I'd suggest that you consider something different. They could be forgiven for not having particularly great-quality sound at that price point...if not for their main drawback. You could likely find something way more reliable with similar functionality for not much more.

    Anyway, let us know about the main mixer/amp/speaker setup. If you get the unit you mentioned, we could give you some ideas how to adequately connect everything.

    Kapt.Krunch
     
  6. RemyRAD

    RemyRAD

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    Of course there are also secondary alternatives to be able to accomplish this mixer into a mixer. For instance, with the proper patch cords, you could take the feed off of the PA board from its inserts. That's provided they are not utilizing their inserts for any sort of external processors/processing. With the proper patch cord, once plugged into the insert of the PA board, the proper patch cord adapter will simply also include the loop through so the PA board continues to work as normal. And you'll be getting a line level output from the mixer which could then more properly feed the line level input to your mixer and/or recorder. And in effect, that way, it basically combines both mixers and allows them both to feed out separate signals in different ways. You would be however subject to any gain trim adjustments on the PA board. But then if you are taking its outputs into your microphone preamps, the same will still apply if you are relying upon the microphone preamps in the PA mixer.

    In on location recording scenarios that I utilize, all the microphones on stage are first plugged into a 24 input splitter box that is transformer isolated and providing 2-3 outputs of each microphone. One set of those outputs would then be plugged into the PA mixer snake box input. Your feed from the splitter would be plugged into your snake box input which will then go directly into your microphone preamps. This is nothing more than an isolated transformer output " Y " style cable patch cord scenario. So the PA guy can screw with gain trim levels and turning faders up and down any way he sees fit, without disturbing any of those microphones feeding your mixer. The trade-off there is that passive transformer or active splitters will instill yet an additional audio character element of its own. Now a lot of people prefer active splitters which are in fact, my least favorite. The reason for that, is that it basically already has its own internal somewhat mediocre microphone preamp before electronically buffering its outputs to numerous output feeds. Whereas a transformer or splitter is simply adding an additional character of a transformer and your microphone preamp will be a more pure representation of the sound of your consoles microphone preamps. I've always enjoyed the sound of the passive transformer splitters. Gain structure is also less variable and fewer mistakes can be made since active splitters can provide for both -50 DB microphone level outputs and a full-blown +4 DB nominal line level outputs. I've had PA bozos feeding me both microphone & line level from different microphones on a single drum set! That's BS! With Transformers, everything comes out at low-level microphone levels. So they are more highly consistent with less nightmare problems to have happened.

    That's why Kapt.Krunch was specifying all of that pre & post fader stuff. But that too can cause you level variations on your tracking. You really don't want that to happen. But hey, 24 x 48 or, 24 x 72 splitters ain't cheap. So, Kapt.Krunch & myself have made numerous suggestions on how to do it on the cheap. And even if some effects like compression are being utilized on microphones, you can split the output for those particular channels at the output of the outboard limiters. They can also feed more than one input simultaneously since they are low impedance output feeding a couple of 10,000/15,000 ohm inputs on both consoles from their PA inserts. You'll still be able to correct for gain trim irregularities & readjustments if the PA guy has made changes during their performance. It just becomes a much bigger pain in the ass. Splitting microphones, you'll never have that kind of pain in the ass to deal with in the mixing and postproduction process.

    I'm going to split... 48 ways now.
    Mx. Remy Ann David
     
  7. Unregistered

    Unregistered Guest

    Same type of question have board types

    My church currently uses an Allen and Heath GL2200 24ch board
    we are looking at putting in a second board so we can get an extra 16 channels (there and abouts)

    We are purchasing a Mackie VLZ 1604 PRO and want to connect this board to the A&H


    any suggestions..?
     
  8. timH

    timH

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    Same type of question have board types

    My church currently uses an Allen and Heath GL2200 24ch board
    we are looking at putting in a second board so we can get an extra 16 channels (there and abouts)

    We are purchasing a Mackie VLZ 1604 PRO and want to connect this board to the A&H


    any suggestions..?
     
  9. RemyRAD

    RemyRAD

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    You've got a number of ways to interface that 16 channel mixer into your Allen & Heath. Now that 1604 has 4 bus outputs which could be utilized as two different stereo pairs of outputs. So this way you can set up both consoles to contain different isolated groups of microphones. So you could just run your 1604 outputs into the GL 2200 inputs 20-24. Then for instance you split the 1604 so that half is for the preachers microphones. The other half might be for the other sanctuary and guest microphones. The bulk of your GL 2200 may then be utilized for the God Squad Rock Band and/or any other musical guests and playback devices. If we had one large console, we would group things that way on the large console. Or utilized extra sub mixers patched into the main mixer.

    Some folks might elect to return that 1604 to the effects return of the Allen & Heath. Leaving those last four of the 24 inputs still available. But that might prevent you from adding some downstream group EQ from one of the group outputs of the 1604. One can certainly work around any of these kinds of problems. You just have to find the right combination that works right in your abstract way of thinking. You might find you want to solo those different group inputs and the echo returns may not feature any soloing capabilities? Which would then force you to go back into those last four of the 24 inputs.

    Conversely, you might want to relegate that 1604 two simply being an expanded 16 input effects return mixer? Which is what I sort of do with the last eight inputs of my 36 input Neve. Simply because I need more than the four returns the console sports. Other times I've occasionally used my Yamaha PM 700 12 x 2 mixer for effects returns or, multiple keyboards or, choral microphones, you get the idea. It's a sub mix and a sub group.

    What you don't really want to do is to take the XLR line level stereo outputs from your 1604 and go into the XLR microphone inputs on the GL 2200. That's a big no no. So it would just be more practical and prudent for you to take the 1/4 inch balanced outputs from the 1604 and shove those into the 1/4 inch balanced or unbalanced line level inputs or effects returns on your GL 2200.

    Some consoles and mixers can actually accommodate 50+ DB gained line level, +4 DB outputs from another mixers output, to the XLR microphone input. This is only possible if that XLR microphone input has 1-2 built in attenuation pads. And you'll need a pad that can attenuate the signal 20-50 DB's to prevent horrendous and unlistenable, 100% overblown distortion. Completely unusable without that input pad on your main desk. There are a lot of people that pooh-pooh that kind of procedure since so many microphone preamps are designed to have some kind of intrinsically desirable and built-in color of its own. Whereas my attitude is, if that microphone didn't go through my Neve or, API stuff, I wanted to go through my microphone preamps to give it that extra sonic signature and that special je ne sais quoi. I mean you can't keep a Mackie or Behringer from sounding like a Mackie or Behringer but you sure as heck can pretty it up a lot more than it would have been. Conversely, if I know something was already tracked through an already good console/preamps, I'll take that incoming microphone line and stick it into the line input, instead of the microphone input, given the opportunity. That's because not all of my jobs can all use a central microphone splitter somewhere on stage. And then you're forced to take another consoles direct, bus and effects send outputs. Sometimes, because of logistics, you can't always just split the microphones on stage.

    Just group stuff by chunks. Stick your foot on it and growl.
    Mx. Remy Ann David
     
  10. timH

    timH

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    Thank you very very much... I really appreciate all the help... :D