How would I wire a long cable (25') to go from my mixer's XLR main out to the 1/4" input of channel 2? The one I have creates a hum when I plug it in. Thank you
Hello jdycus@ec.rr.com ,
There's a great illustration on this page at mediacollege.com .
Make sure you are using cable with two conductors and a shield (i.e., a like a mic cable) rather than a common two-conductor unshielded cable.
While I appreciate the challenge of soldering up your own cables (I've done it myself many times -- with varying degrees of success 😁) I've found many local online sources for good cables at affordable prices that I don't have to hassle with. Amazon has a cable like you need from a reputable manufacturer, at this link: Monoprice 25ft Premier Series XLR Female to 1/4inch TRS Male 16AWG Cable .
Does that help?
Thank you. That is precisely how I have it wired, using XLR mic cable, and it tests good with both a meter and a cable tester. I can pull the 1/4" TRS plug out of Channel 2 1/4" in and all is quiet; plug it back in and get a loud hum. Any other suggestions?
Never mind. Bad idea.
Hello jdycus@ec.rr.com (and Xyz987),
A ground loop is the prevalent cause of hum when connecting two pieces of equipment. However (on soapbox): Please do not use a two-prong adapter to defeat the grounds on your equipment. Doing so would be at your own peril and risk. If a ground loop is the problem, disconnecting the grounds and then touching the equipment could be fatal, cause a severe shock, or damage your equipment. (Off soapbox.) Have we all done it and lived to tell about it? Probably, but please take extreme caution if you're not familiar with test equipment and electricity.
Oh, by the way, you mention you are plugging in to "Channel 2" -- of what? (L1 Pro, S1 Pro, F1, etc.)
Here are some standard troubleshooting questions:
- Since you're using a long XLR-1/4" cable, are your mixer and system are plugged into different wall outlets on different circuits? If so, uneven ground potential could be the cause. Try moving your system next to your mixer (still using the long cable you made) but plugging everything into the same power strip. If that solves the problem, use a long heavy-duty grounded power cord to reach your system if necessary, so you can plug everything into the same circuit.
- Are there any other appliances on the same electrical circuit as your equipment (refrigerator, air conditioner, microwave, etc.)?
- Does your XLR-1/4" cable pass by any electrical equipment between your mixer and system?
- Have you had a chance to try the mixer and system in some other building? This will verify whether it's something in your normal location causing the noise.
- Have you tried this cable with a different mixer to your system, or from your mixer to another system?
- Depending on the make and model of your mixer, it might have an adjustable attenuation switch for the output. Your mixer might be sending a signal that is way too hot (sending a hum) or way too quiet (needing your system to be turned too high, causing a hum.)
Gremlins like this can be irritating to track down. Let us know how you make out!
Does that help?
That's excellent advice.
Thank you. I think your point 1 about different outlets may be the problem. I was set up in a gymnasium size room. My L1 Compact was plugged in at one end of the room, and my mixer at another end. Next time I set up, I will make sure both L1 and mixer are plugged in same outlet.