speakers that hum when plugged into mixer

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-- speakers that hum when plugged into mixer

Posted by Crystalline on Sep-09-2004 06:53:

speakers that hum when plugged into mixer

i'm temporarily using a set of altec lansing desktop/pc speakers for mixing right now. the subwoofer has two sets of inputs, so the pc uses the 3.5mm minijack or whatever, and the auxiliary input is the two RCA plugs, which i use for the mixer, as you might imagine. unfortunately, the second i turn on the mixer, the speakers and subwoofer start humming.

i tried putting the speakers on one surge protector and the mixer on another one, (both on same wall socket), but that had no effect. then i tried using two completely different wall sockets, and still the speakers would hum once the mixer is turned on. what can i do to get around this? thanks for any help!

Posted by tu_face on Sep-09-2004 08:37:

do you use cd decks or turntables? if its turntables, does it still hum when both decks are on..? my mixer used to hum until i switched them both on, then it was fine. this problem has since disappeared altogether since i added my cd deck to my setup which is wierd.

check your phono wires, both from the decks to the mixer, and mixer to amp. try switching them if possible. also check your grounding wires to make sure they are all in order and nice and tight. try and avoid 2 ground wires going to 1 grounding point, although in some cases the mixer will only have 1 anyway. grounding is the most likely cause of any hum, if you do a search in this forum for "ground loop" you should find some useful info. although if you are using cd decks this shouldnt be an issue..

check your carts, take them out and make sure theres no shite in the tonearm socket, or on the pins of the headshell.

also have you tried your mixer in the other input which you use for your computer? minijack>phono wires are easy to come by so it might be worth a try to make sure its not the input on the speakers thats knackered.

Posted by McKee on Sep-09-2004 14:27:

this happended to me, the humming only seemed to come fom the grounding wire at the back of the mixer not being connected properly.

Posted by DJ Joshua H on Sep-09-2004 14:42:

I had a similar problem with my mixer. Try getting an adapter that takes the 3 prong plug (+,-, ground) and turns it into a 2 prong plug minus the ground. its only a couple dollars and worked like a charm!

Posted by tranceaholic on Sep-09-2004 14:52:

quote:
Originally posted by McKee
this happended to me, the humming only seemed to come fom the grounding wire at the back of the mixer not being connected properly.

yup same thing for me.

Posted by don_q on Sep-10-2004 21:34:

I have my setup & my computer connected to my speakers. But every time I use either the other must be disconnected to prevent the common hum. 90% of all hum problems come from the electric system (power source).

Posted by Crystalline on Sep-10-2004 22:16:

i use turntables, not cd decks...but i'm almost certain the turntables have nothing to do with it...the humming through the speakers happens the instant i turn the mixer on. if the turntables were ALREADY on before i touch the mixer, or if i turn them on AFTER the mixer is already on, or even if i disconnect them entirely, it seems to make no difference to the evil hum .

i do actually have a connector that converts RCA to minijack, so i tried plugging the mixer into the speaker input i normally use for my computer, and that also didnt do it, so at least i know its not the speaker's input, anyways. i also have RCA caps on all the unused inputs and outputs on the back of the mixer as well...

the problem may have something to do with the step-up/step-down transformer i'm using...i ordered the mixer from the uk because it was $100 cheaper, so i had to get a transformer to convert the wall's 110v to the 240v that the mixer uses. i'm certainly not an electrician, but since i'm using something like that to convert different voltages, i would personally be a little wary of bypassing the ground entirely by using a 3-prong to 2-prong adapter. could bypassing the ground cause harm to your equipment? or is it only there for safetey reasons, and the lack of it wouldn't cause any problems?

Posted by mndeg on Sep-11-2004 02:42:

my logitech z560 dont

Posted by don_q on Sep-11-2004 14:03:

quote:
could bypassing the ground cause harm to your equipment? or is it only there for safetey reasons

Guess you answered yourself
Yeah its there for safety reasons, so, it could harm your equipment. However a Good surge protector could prevent the harm. But I recc. do not bypass that 3rd leg.
Have you talked with other owners of that mixer?
Its pretty obvious, but you're shure its an electric power hum right? Remb. its a 60Hz hum.

Oh, and if it is the transformer, its gotta be a very shitty one

Posted by xXxAzNrAvErxXx on Sep-11-2004 16:21:

I have the same problem also..the hum is very loud when I turn on my mixer. Could it be the mixer itself? I have a pioneer djm300.

Posted by Briden on Sep-12-2004 18:40:

quote:
Originally posted by don_q
Guess you answered yourself
But I recc. do not bypass that 3rd leg.

I always try to get my wife not to bypass that 3rd leg.

Posted by vhx1 on Sep-13-2004 02:12:

What kind of mixer is it? I have a behringer djx700 and i have the same problem. what a piece of shit mixer fuck

Posted by rainbow_marble on Sep-13-2004 09:01:

perhaps a grounding issue... check for it

Posted by 6iki_Snake on Sep-13-2004 09:54:

The thing with my turntables is that the endings are just a tiny bit wider then the socket on my mixer. Just squeeze the metallic ending of the plug that is attached to the TT a bit so that they make better contact. This could help you with your buzzing problem. You stated that this problem is there even when you switch your decks off. This could also be a problem in the plugs from the line that goes to your amplifier from your mixer.

Posted by tu_face on Sep-13-2004 13:18:

have you always got the computer plugged in?

mine always used to buzz whenevr i hooked up my mixer to the computer, or even if they were connected to the same equipment (i.e. my amp.. ?? curious)

it has since fucked off since i added a cd deck and moved my decks away from the computer.

Posted by xXxAzNrAvErxXx on Sep-13-2004 23:17:

how do you know if your decks has been grounded correctly?
I think the problem is from my mixer, once I turn in on..all hell breaks loose. For now I just turn down the level on my mackie's to deal with this issue. I am just waiting on my new mixer to come, and hopefully this problem will go away.

Posted by Crystalline on Sep-17-2004 06:07:

the speakers also STILL hum even if the computer is off and unplugged AND the turntables are off and unplugged too. i don't get it! :(