Noisy PA

[crossfireband.biz]

...I run sound for a band we have good quality epuipment...at practice I run the full pa and its nice and crystal clear..with no additional hums or noise...I have a 16+4 100' snake ran an everything...again nice and clean sound.....when ever we set up to play out I get nasty hums from all instrumentation channels...as soom I turn up any instruments (guitars or keyboards ;anything fed from a "pre" amped source....not drum mics they are fine)a nasty hum...this is with everything set up EXACTLY the same as practice wires and all...electrical phase problem ?? or what?? How do I remove the nasty noise ..is it as eaxy as putting inline direct boxes/hum eliminators or 2 - 8channel rack mount "hum eliminators" or is it something else? :confused:

[devildriver421]

The only thing I can think of is if the speaker cables are unshielded they'd be picking up alot of noise. I'm not sure though

[crossfireband.biz]

I dont think it could be that the cables I use have twine inside them and they are really big(cant remember what guage)but nice and fat..We have all pro equipment .. thoughts on the hum eliminator??

[devildriver421]

you only need to bump something to get it back onto the first page so people see it, not when its the 4th thread down. spamming

[diesel]

I'd say to check that you're running all your gear off the same panel, with the same ground point, this sounds like a ground loop.

[Aes820]

Yes. A grounding problem would be my first guess. A ground loop hum can occour if your equpiment is using multiple grounding points.

If you are running equipment direct to the mixer see if you can lift the ground off individual items to see if you can isolate and eliminate the trouble maker.

I'm always a little bit hesitant with lifting the ground off amplifiers that the musician is playing through if they are also going to be coming into contact with other possible grounding points. Like microphones.
I've heard stories about guitarists touching their lips up to a mic and copping a heap of volts through their kissers.

Although a sure-fire way of stopping a ground loop hum would be to ensure that everything at the gig is being ran off the one electrical circuit. With just the one common grounding point.

Balance everything, If you can. f you are running equpiment direct then use a DI box.

Apart from that. Make sure that your electrical cables are not running in parrallel with signal cables. Even if signal cables are shielded you can get some interference. So keep a bit of distance between these two if you can, and if they do have to cross paths do so at a perpendicular angle.

[crossfireband.biz]

If I can't trace all the electrical circuts at the clubs we play at to insure we are on the same circuts...will the hum eliminator ground loop thing work...
I always seperate electrical wires from PA cables...far apart..

[crossfireband.biz]

anyone else????

[crossfireband.biz]

Bump