souprice
my hardware -
desktop pc
pioneer ddj wego (usb powered)
two Rokit5's
i've googled and brought both Hum X, Ground loop isolator RCA cable but humming still exist. i am running a DESKTOP pc, not laptop like most ground loop issue easily fixed by running on battery. i can't do that on desktop pc.
my setup -
wall outlet -> surge protector 8
1) hum x -> power supply
2) monitor
3) left powered speaker
4) right powered speaker
5) cable modem
6~8) empty
i've tried the hum X on wall outlet then to the speaker and the buzzing noise got 10 times worse
also tried the hum x on monitor (where i connect the USB WeGo) to, noise still there
both my rk5 powered speakers are connect to Nexxtech Ground loop isolator and the noise is reduced by 40%
the noise got worse as soon as i turn on the usb DDJ
the main issue comes from usb ddj itself... i don't know what to do anymore...
desktop pc
pioneer ddj wego (usb powered)
two Rokit5's
i've googled and brought both Hum X, Ground loop isolator RCA cable but humming still exist. i am running a DESKTOP pc, not laptop like most ground loop issue easily fixed by running on battery. i can't do that on desktop pc.
my setup -
wall outlet -> surge protector 8
1) hum x -> power supply
2) monitor
3) left powered speaker
4) right powered speaker
5) cable modem
6~8) empty
i've tried the hum X on wall outlet then to the speaker and the buzzing noise got 10 times worse
also tried the hum x on monitor (where i connect the USB WeGo) to, noise still there
both my rk5 powered speakers are connect to Nexxtech Ground loop isolator and the noise is reduced by 40%
the noise got worse as soon as i turn on the usb DDJ
the main issue comes from usb ddj itself... i don't know what to do anymore...
geposted Sat 29 Dec 12 @ 12:01 pm
cstoll
On thing you can try is to use an RCA to 1/4" adapter and use the balanced TRS connection on the back.
Alternatively, from the KRK Rokit manual -
• All audio equipment should use the same ground point. Check all other devices using the same AC output in the building such as dimmers, neon signs, TV screens, and computer monitors. These devices should not be using the same circuit.
So, put your monitor and/or computer on a completely different circuit and see if that eliminates the 'hum'.
Alternatively, from the KRK Rokit manual -
• All audio equipment should use the same ground point. Check all other devices using the same AC output in the building such as dimmers, neon signs, TV screens, and computer monitors. These devices should not be using the same circuit.
So, put your monitor and/or computer on a completely different circuit and see if that eliminates the 'hum'.
geposted Sat 29 Dec 12 @ 2:26 pm
blckjck
Does the hum happen on the speakers with nothing connected to them, just them powered up? You may be getting interference from something else on the circuit.
Do you hear the hum in headphones?
Does your outlet have a ground hooked up to it? Some older wiring may not even have a ground connected.
Can you try directly from the PC to the speakers? Is there a hum?
Do you hear the hum in headphones?
Does your outlet have a ground hooked up to it? Some older wiring may not even have a ground connected.
Can you try directly from the PC to the speakers? Is there a hum?
geposted Sat 29 Dec 12 @ 5:40 pm
souprice
cstoll wrote :
On thing you can try is to use an RCA to 1/4" adapter and use the balanced TRS connection on the back.
Alternatively, from the KRK Rokit manual -
• All audio equipment should use the same ground point. Check all other devices using the same AC output in the building such as dimmers, neon signs, TV screens, and computer monitors. These devices should not be using the same circuit.
So, put your monitor and/or computer on a completely different circuit and see if that eliminates the 'hum'.
Alternatively, from the KRK Rokit manual -
• All audio equipment should use the same ground point. Check all other devices using the same AC output in the building such as dimmers, neon signs, TV screens, and computer monitors. These devices should not be using the same circuit.
So, put your monitor and/or computer on a completely different circuit and see if that eliminates the 'hum'.
my Rk5s are using unbalanced cable right now, i may have to try the RCA to 1/4
i've tried both the ac / monitor OR speakers on different wall plug, buzzing sounds are the same
blckjck wrote :
Does the hum happen on the speakers with nothing connected to them, just them powered up? You may be getting interference from something else on the circuit.
Do you hear the hum in headphones?
Does your outlet have a ground hooked up to it? Some older wiring may not even have a ground connected.
Can you try directly from the PC to the speakers? Is there a hum?
Do you hear the hum in headphones?
Does your outlet have a ground hooked up to it? Some older wiring may not even have a ground connected.
Can you try directly from the PC to the speakers? Is there a hum?
the speakers hum are minor until i turn on the USB ddj, so i think the USB ddj is causing the ground loop. i've ordered a usb isolator from ebay hopefully it will get rid of this usb problem.
i can hear a little hum in headphone, not sure about my outlet as it's two sets of 3 prong. i don't have the proper cable to test out from my to speaker plus my sound card is disabled and i'm using a usb wireless headphone
geposted Sat 29 Dec 12 @ 6:26 pm
blckjck
Is the minor hum present without anything hooked up to the speakers, not just with the ddj off?
Is there anything else connected to your PC, like a TV tuner card, cable modem via USB, etc...
Is there still a hum with only your headphones plugged in, not the ddj....
It's starting to sound like you are getting interference from the AC main in, and that gets amplified the more stuff you add. Are you able to move your equipment or run a grounded extension cord to a completely different circuit, say a kitchen or bathroom outlet?
Even if the outlet is 3 prong, it may not have the ground connected properly. There are low cost outlet testers available at the hardware store that can test if the outlet is wired properly.
Is there anything else connected to your PC, like a TV tuner card, cable modem via USB, etc...
Is there still a hum with only your headphones plugged in, not the ddj....
It's starting to sound like you are getting interference from the AC main in, and that gets amplified the more stuff you add. Are you able to move your equipment or run a grounded extension cord to a completely different circuit, say a kitchen or bathroom outlet?
Even if the outlet is 3 prong, it may not have the ground connected properly. There are low cost outlet testers available at the hardware store that can test if the outlet is wired properly.
geposted Sat 29 Dec 12 @ 6:36 pm
Dazmax
This problem has become far more common as more people choose to use powered speaker systems.
To give you an idea of why it happens. Imagine a triangle with a powered speaker at two of the corners and a sound card at the third. Now imagine the power cables for all three items connecting to a single point in the center of the triangle. No problem yet. Now we connect all three corners of the triangle together with audio leads and as if by magic you have a perfect example of a wiring setup that can generate ground loops galore. We have to break the triangle in a safe way by isolating audio screens/grounded connections to stop the loop forming. If you have any concerns regarding the quality of the protective earth/ground on your power outlet here is an example of a standard easy to use tester. It simply plugs in to your electrical outlet and will instantly show if the outlet is correctly wired.
If you can stretch to buying a Dual DI (Direct inject) box like this.
This box wil convert from the single ended outputs on your Pioneer to a balanced signal to connect to the speaker inputs. This box provides total isolation between the controller and the amps in your loudspeakers. You would use this to connect the output from your controller to your amplified speakers. Use the Ground lift switches to break the audio ground and the loop should be cleared. In effect you are removing two sides of the triangle in one go.
Good luck
Daz
To give you an idea of why it happens. Imagine a triangle with a powered speaker at two of the corners and a sound card at the third. Now imagine the power cables for all three items connecting to a single point in the center of the triangle. No problem yet. Now we connect all three corners of the triangle together with audio leads and as if by magic you have a perfect example of a wiring setup that can generate ground loops galore. We have to break the triangle in a safe way by isolating audio screens/grounded connections to stop the loop forming. If you have any concerns regarding the quality of the protective earth/ground on your power outlet here is an example of a standard easy to use tester. It simply plugs in to your electrical outlet and will instantly show if the outlet is correctly wired.
If you can stretch to buying a Dual DI (Direct inject) box like this.
This box wil convert from the single ended outputs on your Pioneer to a balanced signal to connect to the speaker inputs. This box provides total isolation between the controller and the amps in your loudspeakers. You would use this to connect the output from your controller to your amplified speakers. Use the Ground lift switches to break the audio ground and the loop should be cleared. In effect you are removing two sides of the triangle in one go.Good luck
Daz
geposted Fri 04 Jan 13 @ 3:50 am
souprice
i finally received this in the mail only to found out this didn't work :'(
i may have to try DI Box, but the one you posted doesn't have USB input on it!?
i may have to try DI Box, but the one you posted doesn't have USB input on it!?
geposted Thu 17 Jan 13 @ 12:19 am
groovindj
Here's a possibility...
A few years ago when I used to DJ with a rack mount PC, I found that the LCD monitor was the cause of hum through my system.
I had to lift the ground connection of the monitor to solve it.
A few years ago when I used to DJ with a rack mount PC, I found that the LCD monitor was the cause of hum through my system.
I had to lift the ground connection of the monitor to solve it.
geposted Thu 17 Jan 13 @ 8:53 am
souprice
yeah actually my usb connection is through my lcd monitor's usb slot, however i already tried plugging the humX to the lcd's plug but still the same.
geposted Thu 17 Jan 13 @ 8:30 pm
blckjck
Have you tried not using the USB hub in the monitor, go directly to the tower.
Also, try disconnecting the monitor and see if the hum goes away. I also asked a few questions further up.
Also, try disconnecting the monitor and see if the hum goes away. I also asked a few questions further up.
geposted Thu 17 Jan 13 @ 9:44 pm
Dazmax
Good idea Blckjk :-)
Is the power supply for the LCD monitor internal or external? If it is external then a double insulated replacement power supply could well help. I would suggest plugging the controller directly to the PC anyway.
Would be worth conducting some checks and recording the results to avoid confusion. If you are convinced the problem is USB related try removing one connection at a time on your USB cables record what if anything happens and then do the same with each power cable and each audio cable. You might have a combination of issues so wrighting down the results could help give you a clearer pictureof what is happening. Perhaps you could make a layout drawing of your system and post it so that we can see exactly how you have everything hooked up.
Ground loops form in the inter connecting cables and power lines of any unbalanced system where the inter connecting cables combine a screen/signal return with equipment that used a protective earth/ground connection. If there are multiple paths to ground for the small ground currents and any resistence in the cables, a ground loop is formed.
Some good housekeeping :- Make sure all the cables supplying equipment are fed from the same outlet, Avoid long runs of unbalanced signal cables (This includes USB). Use the best quality cables you can afford. Avoid (as much as possible) different lengths of power cables. Ideal is to bring all the power cables to a single point multi socket. Don't bundle power and signal cables together. If power and signal cables must cross each other then it should be a right angles. Convert as much of the signal cabe as is practical to balanced line using transformers (DI box is an example). Ensure all protective earth/ground wires are connected and that the outlet you are using is propperly grounded.With USB cables try wherever possible to run these directly from your computer to the device and not via external Hubs.
It is unusual for ground loops in USB lines to be the direct cause of audible hum issues. If the hum stops when you disconnect a USB cabe this could well be a sign that your problem is elsware in the audio signal chain. Disconnecting the USB cable might stop or break part of the loop but the loop could well be forming in the audio signal lines. These would always be my first port of call with this kind of issue.
From a safetey point of view. NEVER!!!!! lift/isolate or disconnect a protective Ground/Earth on any equipment in an attempt to cure hum issues.
Good luck
Daz
Is the power supply for the LCD monitor internal or external? If it is external then a double insulated replacement power supply could well help. I would suggest plugging the controller directly to the PC anyway.
Would be worth conducting some checks and recording the results to avoid confusion. If you are convinced the problem is USB related try removing one connection at a time on your USB cables record what if anything happens and then do the same with each power cable and each audio cable. You might have a combination of issues so wrighting down the results could help give you a clearer pictureof what is happening. Perhaps you could make a layout drawing of your system and post it so that we can see exactly how you have everything hooked up.
Ground loops form in the inter connecting cables and power lines of any unbalanced system where the inter connecting cables combine a screen/signal return with equipment that used a protective earth/ground connection. If there are multiple paths to ground for the small ground currents and any resistence in the cables, a ground loop is formed.
Some good housekeeping :- Make sure all the cables supplying equipment are fed from the same outlet, Avoid long runs of unbalanced signal cables (This includes USB). Use the best quality cables you can afford. Avoid (as much as possible) different lengths of power cables. Ideal is to bring all the power cables to a single point multi socket. Don't bundle power and signal cables together. If power and signal cables must cross each other then it should be a right angles. Convert as much of the signal cabe as is practical to balanced line using transformers (DI box is an example). Ensure all protective earth/ground wires are connected and that the outlet you are using is propperly grounded.With USB cables try wherever possible to run these directly from your computer to the device and not via external Hubs.
It is unusual for ground loops in USB lines to be the direct cause of audible hum issues. If the hum stops when you disconnect a USB cabe this could well be a sign that your problem is elsware in the audio signal chain. Disconnecting the USB cable might stop or break part of the loop but the loop could well be forming in the audio signal lines. These would always be my first port of call with this kind of issue.
From a safetey point of view. NEVER!!!!! lift/isolate or disconnect a protective Ground/Earth on any equipment in an attempt to cure hum issues.
Good luck
Daz
geposted Fri 18 Jan 13 @ 1:47 am
tayla
If the hum goes when usb cable is disconnected get a hold of a decent "ground loop isolator" this will usually have a pair of rca male /female input/output connectors on them. UK cost is around about £10.00
If your going straight to the speakers from the mixer you will need a balanced RCA/XLR converter lead to come out of the isolator, if using XLR runs. cost £5.00
(you can always hide these isolators and put them inline inside a flight case (if you use one) from the mixer)
If still experiencing problems try using an IEC filter socket on your pc tower. Cost £4.00
Hope that helps.
If your going straight to the speakers from the mixer you will need a balanced RCA/XLR converter lead to come out of the isolator, if using XLR runs. cost £5.00
(you can always hide these isolators and put them inline inside a flight case (if you use one) from the mixer)
If still experiencing problems try using an IEC filter socket on your pc tower. Cost £4.00
Hope that helps.
geposted Fri 18 Jan 13 @ 8:32 am
blckjck
If your interested, here is a great article on sound equipment interconnection and ground potential differences.
http://www.rane.com/note110.html
Here is another one that goes into a little more depth with pro audio connection.
http://www.rane.com/note151.html
http://www.rane.com/note110.html
Here is another one that goes into a little more depth with pro audio connection.
http://www.rane.com/note151.html
geposted Sat 19 Jan 13 @ 2:30 pm
souprice
thanks for the help guys. i got rca to xlr cable today and it finally got rid of 90% of the humming noise. i've hooked up xlr from speaker to ground loop isolator to pioneer ddj wego, that seem to get rid a lot of humming noise compare to before using standard rca cable.
geposted Sat 19 Jan 13 @ 8:03 pm
tayla
Glad it helped.
geposted Sun 20 Jan 13 @ 6:28 am