Is it ok to put an unbalanced 1/4 inch line through an XLR stage snake?

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I've been tasked with setting up and doing sound design for an upcoming live event.Unfortunately, the equipment I have to work with is somewhat lacking.

The analogue mixing desk (Allen & Heath ZED-14) only has 6 XLR inputs, two of which will be used for vocals and four for the drum kit. That leaves four tracks with 1/4" L/R inputs - keys 2 guitars and bass.

The problem is, my stage snake only has XLR connections from stage to desk. I've considered slapping a DI on each line on stage, but at the mixer end I have 1/4" inputs which don't need to be balanced, so it seems redundant.

Is it enough to simply stick them into a 1/4" --> XLR connector on stage and then XLR --> 1/4" at my end?

What would be the pros/cons of each set up?

Cheers!

Orchestral Violinist

Posted 2017-07-03T04:56:30.283

Reputation: 3

If you have the option, use DIs to be on the safe side. – Dalv Olan – 2017-07-03T05:21:32.603

If you intend to use the output of bass/guitar, you need a DI to adapt instrument level and impedance to line level, be it balanced or not. – audionuma – 2017-07-03T06:57:19.130

Answers

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According to the manual ( http://www.allen-heath.com/media/AP6822_5+ZED14_18_24UG.pdf ), the line inputs on this mixer are balanced. So, use an XLR to TRS adapter cable and that takes care of the balancing issue.

However, the bigger problem here is the level of the signal you are dealing with. The line input channels have a max nominal sensitivity of -26dBu while the mic inputs have a sensitivity of -63dBu.. so you cannot plug any microphones into these inputs without a preamp. This will be a problem for your guitars.

For bass, check to see whether you have a line level output on the amp being used.. some amps don't have them so check ahead of time.

For keyboards, if an amp is not being used, you will probably be ok taking the output of the keyboard.. either directly or via a balancing box. In this situation you actually don't want a regular DI because the impedance conversion (high impedance line input to low impedance mic output) will result in a lower level coming into the mixer, which is the opposite of what you want. Ideally you want something with 1:1 isolation such as the ART DTI which gives you two channels of 1:1 balancing in one fairly inexpensive box.

Of course if there's no amp for keys, you need to provide a monitor channel for them.

If an amp is in use and there's a speaker output that is active at the same time as the internal speaker, there are DI's with attenuators suitable for connecting speaker outputs to mic or line inputs.

Bottom line is, make sure you know what sources you've got to work with going into this. If you need two more mic inputs for the guitars anyway, you might want to just borrow or rent yourself a second small mixer somewhere to submix the extra inputs.. for example if you submix the drums on another mixer and bring that into a line input you'll have enough mic inputs for everything and will be able to avoid the line input issue, then you can mic your guitar amps without issue and use ordinary DI's for the line sources.

little_birdie

Posted 2017-07-03T04:56:30.283

Reputation: 411

Thank you very much! This cleared up quite a few things. The second mixer idea is really useful. Thanks! – Orchestral Violinist – 2017-07-06T22:11:59.920