Whenever my computer is connected to my monitor speakers they generate a very annoying hum.
I thought it was because I was connecting the line out directly to the speakers. Which admitedly is not a great idea but when cash is short I can’t be picky. Anyway, I bought a Tascam USB soundcard hoping it would fix the problem, but it is still there. My other thought is that it could be the wires I was using. I should opt for some stereo audio to xlr cables instead of to 1/4" jack. Though I’m not sure it would solve the problem.
If you’re on laptop, try with battery power, or some other device with battery operation like mp3 player, that should tell you is it grounding problem or not.
Hooking speakers and computer on same grounded extension cord may help, you can also try changing polarity (plug power cord 180*degrees other way, try different combinations).
Balanced Jack (TRS) should give you same performance as XLR.
If you have loud active speakers, it’s good to have passive volume controller between audio source & speakers, like SM Pro Nanopatch, so you can output at full volume from computer.
Also check cables nearby your speaker cable, or maybe USB-Devices (they make funky noises when data is transfered). Maybe there’s a “crosstalk” problem.
But if it’s a constant hum (let me guess: the noise is around 50Hz? ), it’s most probably a grounding problem and not a shielding issue…
You don’t have a ground lift switch on your usb sound card/interface thing, or on monitor amp? Prolly a small 2 position switch maybe on the back or bottom, even. Sometimes labeled ‘ground loop’ or ‘earth’ instead of ground lift. If not, maybe you can get a cheap direct box with a ground lift and incorporate it somehow into your setup. Kind of a slightly redneck solution, though.
edit:now that i think about it, if you do have ground lifts on your tascam, they are prolly only for fixing grounding probs with mics/line ins.
i always had a buzz on my laptop when the power cord was plugged in, but one of these removes it… RadioShack
not too expensive, they can be got in Maplins here in Ireland, (though you will find them in the car section).
Maybe it will help you too
Some D.I boxes are also able to remove noise and hums too, as i found out recording some bass the other day
i figured i’d add to this topic instead of starting a new one since its kinda the same sorta thing
i sometimes record audio from tv or my phone, so headphone out on phone through a jack-jack cable, and sound out through the tv via rca-jack cable, into the mic input on my laptop. the problem is that the audio always comes with a metal-ly sound, sort of phasing metal or something. it’s actually quit a nice effect, but obviously it screws with the recordings.
did some Googling but couldn’t find out exactly what the problem was. maybe someone here knows?
Actually, your suggestion is prolly better than my d.i. box idea. I’ve never seen a “Ground Loop Isolator” that cheap though (usually around 60-80 bucks, dang…), so i skipped it. ‘People’ say lifting grounds is potentially dangerous for gear but i’ve never had probs with line level or smaller signals… Anyway, getting a hold of either device is not a waste of cash, imo, 'cause they would both otherwise be useful sooner or later.
I got the buzz down to a minimum by plugging the monitor into a seperate outlet than the speakers. It’s still there. But I suppose t could be a wire sheilding issue so I am going to try some better cables and see if I can eliminate it completely.
True but I have been informed when trying to help others that some laptops only have a single input, usually labeled as Mic In, which is used for both Microphone and Line levels inputs with the input sensitivity set by software.
Anyway Rhowaldt started his own thread and has come to a solution so no point in staying on the off topic conversation as far as the original post goes.