Jump to content


Please note: You can easily log in to MPN using your Facebook account!

Daisy-chaining of keyboard audio


Andre Lower

Recommended Posts

Like many other players, I normally use more than one keyboard to play live. One of the nags involved is the need to connect the audio OUTS of each board to the stage mixer (which takes the audio to a power amplifier and from there to the PA and monitor systems). It really bugs me to have to provide two 20 or longer quality audio cables for every single piece of gear I use :mad: . I considered patching the audio OUTS of my XP-30 to the audio INS of my Nord Modular, and then only the audio outs of the Modular to the stage mixer. But there are many problems to it, being the worst the requirement of a pre-amp patched upstream of the Nord (otherwise it simply kills the audio coming from the XP-30 too low audio level). So here goes the question to the technicians around: Why is it not feasible to mix unamplified (instrument level) audio signals? Why must it be line level? Is everybody else that uses more than one board to play stuck with the choice of either bringing around a sub-mixer (just for mixing the keyboard audio outs before sending it to the stage mixer yet another piece of gear to drag around...) or bringing a pair of very long audio cables for each keyboard :confused: ?
"I'm ready to sing to the world. If you back me up". (Lennon to his bandmates, in an inspired definition of what it's all about).
Link to comment
Share on other sites



  • Replies 7
  • Created
  • Last Reply

The outputs of keyboards are just very low power amplifiers. Amplifiers have an output impedance and mixers have an input impedance. Outputs are low impedance, inputs are high(er) impedance.

 

If you Y-cord 2 keyboards together into an input, their output signals try to drive the lower of the other 2 impedances (electricity seeks the easiest path). The lower impedance is the output impedance of the other keyboard.

 

This is in laymen's terms, but this is what is basically happening. So, yes, you need to electrically mix the signals. Without a submixer, you need to run separate cables.

Link to comment
Share on other sites

Originally posted by Prague:

The outputs of keyboards are just very low power amplifiers. Amplifiers have an output impedance and mixers have an input impedance. Outputs are low impedance, inputs are high(er) impedance.

 

If you Y-cord 2 keyboards together into an input, their output signals try to drive the lower of the other 2 impedances (electricity seeks the easiest path). The lower impedance is the output impedance of the other keyboard.

 

This is in laymen's terms, but this is what is basically happening. So, yes, you need to electrically mix the signals. Without a submixer, you need to run separate cables.

Good description of what happens. You can run a real simple mixer with a resistor per input all joined to the output that will overcome this but its going to tend to be noisy.

 

So a mixer really is the only option. I use one capable of balanced outs and run balanced downstream which avoids a lot of problems.

Link to comment
Share on other sites

At least the PA systems that I've worked with haven't been stereo, then it's 2 DI's & 2 XLR cables per board to the snake. Sometimes 2 XLR's have to connected together to reach the snake.

Steve

 

www.seagullphotodesign.com

Link to comment
Share on other sites

True it is another piece of gear but there are single or double space rack units, that wouldn't be much.What about using a sub-mixer on stage and just feeding that to the FOH. Do the FOH mixers hate that or what? I would think that as long as you balance the levels of your individual synths to give the same output a sub-mixer would work out well. Then you would have some control over them on stage as well. 'course I don't dare play live, cuz I suck at keys, so I could be off here. True it is another piece of gear but there are single or double space rack units, that wouldn't be much especially given if you already have a rack of gear.
"When I look at the smiles on all the children's faces,,...I just know they're about to jab me with something." -Homer J. Simpson
Link to comment
Share on other sites

a small 4 or 6 channel desk (one of those Behringers would be fine) is small, would probably pack right into the back of your rack when you're moving it or into a small bag or whatever and is quickly setup. You're plugging line levels, so the shoddy Behringer pre-amps aren't so much an issue. I think as soon as you have a few boards on stage with you and realize how simple it is for you to adjust your own levels having a submix in front of you, the benefits will quickly outweigh the extra gear. :)

"You look hopefully for an idea and then you're humble when you find it and you wish your skills were better. To have even a half-baked touch of creativity is an honor."

-- Ernie Stires, composer

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...