Littoral
1367 posts
Feb 19, 2016
4:14 AM
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I know the signal is "better" with an XLR but can someone tell me how? What I'm actually losing with a pedal rig if I go 1/4" to the PA, other than signal "quantity"?
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NathanLWBC
81 posts
Feb 19, 2016
6:33 AM
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A couple of things come into play. Probably the biggest reason is that XLR is far more resistant to noise than 1/4". When cable is run in excess of 20', which is almost a certainty when going into FOH, 1/4" is almost guaranteed to experience some sort of interference, whether it be from cell phones, radios, etc. XLR is almost completely impervious to such interference, making it a much more stable connection.
Also, just like the battle with a guitar amplifier, a PA assumes a 1/4" input has a very low output. Guitar/bass pickups put out a very low level when compared to a microphone, so there is much more gain in the channel than the XLR input, which is setup for a mic.
I'm, obviously, being a bit simplistic, but I think you get the idea. For going straight to FOH, I always recommend a DI box at the tail end of your board for two reasons.
1) You can send XLR to FOH
2) The sound tech can plug his house XLR cable straight into your rig with no headaches. A happy sound tech = a happy musician
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--Nathan Heck
Lead Technician, Lone Wolf Blues Co.
customerservice@lonewolfblues.com
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Littoral
1368 posts
Feb 19, 2016
7:09 AM
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Thanks Nathan.
So, it is essentially signal quantity (gain) IF the PA board is on stage and the 1/4 cable is less than 20'?
You didn't mention anything in terms of signal quality (EQ, etc.) so the quality shouldn't be compromised? Interference could still be an issue with all of the other gear on stage so my real question is:
Will I gain any perceptible quality with an XLR connection?
My preference is certainly a DI or an IMP even better to eliminate another box because I'm trying to set up in less than 1 minute with a 2 pedal rig: LW Octave and Delay. Having my own channel is easier than switching out an existing vocal mic. Not necessarily quicker but better.
And yes, all, playing the house PA 58 is quickest and good enough.
Last Edited by Littoral on Feb 19, 2016 7:16 AM
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NathanLWBC
82 posts
Feb 19, 2016
7:21 AM
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No problem.
If the PA is on stage, I wouldn't sweat it too much. If there is any perceptible tonal difference, I've never noticed it. As long as you are able to reach suitable levels before feedback with the increased gain in the 1/4" channel, then I would do that if it is more convenient.
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--Nathan Heck
Lead Technician, Lone Wolf Blues Co.
customerservice@lonewolfblues.com
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Greg Heumann
3177 posts
Feb 19, 2016
8:38 AM
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The XLR inputs are connected to "mic preamps" in the mixer/PA. The 1/4" inputs are frequently not, so some of the front panel controls like gain adjustment won't work on the 1/4" side. If you get a sound you're happy with through the 1/4" input, be happy.
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***************************************************
/Greg
BlowsMeAway Productions
See my Customer Mics album on Facebook
Bluestate on iTunes
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hvyj
2968 posts
Feb 20, 2016
7:57 AM
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Yeah, the 1/4" inputs bypass the board's preamps. BUT, if you are going thru effects pedals, those function more or less as a preamp. Personally, I think a multi effects unit works better with a PA and pedals work better with an amp, but YMMV.
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mlefree
588 posts
Feb 20, 2016
3:02 PM
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I'm not sure it is what you are looking for Littoral, but here is a more technical answer to your question.
XLRs are "balanced" cables. That means that there are two signal wires, not just one as is the case with unbalanced 1/4" cables.
Each signal wire picks up ElectroMagnetic Interference (EMI -- noise). With balanced cables, the polarity (+/-) of the two signals are reversed at the "sending" end and then summed at the "terminating" end. This has the desirable effect of cancelling the noise common to both signal wires. Obviously this is impossible with a single signal wire.
So, theoretically, XLR cables inherently have higher signal to noise ratio than 1/4" cables.
But as Greg says, in the real world, the proof is in the pudding.
Michelle
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SilverWing Leather - Custom leather creations for musicians and other eccentrics.
Last Edited by mlefree on Feb 20, 2016 3:03 PM
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Greg Heumann
3179 posts
Feb 20, 2016
4:08 PM
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Thanks, Michelle - but to be (painfully) clear - XLR connectors are unfortunately used in both balanced and unbalanced cables - so I'm afraid XLR does not signify balanced wiring.
Balanced cables are used in low impedance applications, and would be either an XLR male to XLR female or XLR female to 1/4" stereo (AKA "TRS") plug.
XLR to 1/4" MONO cables are wired UNbalanced and come in two flavors called Pin 2 Hot and Pin 3 Hot. They are both for high impedance connections. Pin 2 Hot is more common these days but there's still a lot of "legacy" Pin 3 Hot stuff running around, with 2 notable examples in our world. One is the Hohner Blues Blaster; the other is a Shure 545 reset to high impedance operation according to the factory instructions.
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***************************************************
/Greg
BlowsMeAway Productions
See my Customer Mics album on Facebook
Bluestate on iTunes
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mlefree
589 posts
Feb 20, 2016
5:28 PM
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Thanks, Greg!
I knew if I gave the Reader's Digest version you'd come back with the real scoop. I just wondered why you didn't before.
Michelle
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SilverWing Leather - Custom leather creations for musicians and other eccentrics.
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