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When running sound for a group with keyboards and other devices that have balanced outs, I will often run them through the same snake and attach them to the line level input on my mixer. I don't generally use a DI box in cases like this, unless dealing with a DJ mixer or something that doesn't have balanced outs.

I was once told that I should use a DI box for everything line level, rather than using my method, to avoid impedance issues with long cable runs.

I don't really understand this reasoning. Is it true? And if so, can you help me understand it?

If it is true, then why isn't it an issue for setups with a dedciated monitor mixer, and line-level direct outs going to FoH?

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migrated from Jan 27 '14 at 15:26

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I've run into this as well. I get to a gig and give the soundguy my 5 channels of balanced line levels, and he invariably grumbles that they're way too hot and that I don't know what I'm doing. I've concluded that they just always assume everything coming from the stage is mic level, so now I pad them with -12dB. – lukecyca Dec 15 '10 at 22:28
@lukecyca: 1. Are you giving him balanced 1/4" or balanced XLR? 2. The pads should be placed at the mixer end of the cables instead of the source for best immunity to interference, though it might not make much practical difference. – endolith Dec 20 '10 at 21:05
@endolith: I have balanced 1/4" jacks on various rack gear in my rig, and my own 4' snake which converts them all to XLR. I give the sound guy the XLR end to plug into his stage snake to go back to his mixing desk. The correct way is probably to give line level. However, I've found that a happy sound guy is more important for my sound quality than correct gain structure. – lukecyca Dec 21 '10 at 21:21
@lukecyca, He is expecting mic level from you, and you are giving him line level. You should probably get a few DI boxes for times like this. You might be able to get away with a -40dB pad. I generally stick to 1/4" TRS for line level stuff, and XLR for mic level stuff. Of course this isn't always possible (particularly on my DriveRack and powered speakers), but just make mental note of the few exceptions. – Brad Dec 21 '10 at 21:26
@lukecyca: I just mean the sound guy would probably be happy with line level if you gave it to him on 1/4" balanced plugs instead of XLR. The mixer inputs should be made for that. – endolith Dec 21 '10 at 21:26
up vote 4 down vote accepted

Line level balanced out to a line level balanced input on a mixer is the best connection there is for long cable runs. Line outs have small source impedances that are good at driving long cables.

I'm not sure what you mean by "use a DI box for everything line level". DI boxes turn a high output impedance into a low output impedance, but line outs already have low output impedance.

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Alright, that's what I thought. Thanks for clarifying! – Brad Dec 16 '10 at 15:50

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