Speaker hum when ProTools launches

[annapretorius]

Hi there

I am running Protools 12 with the Avid fast track duo and rokit 5 powered monitors.

As soon as I launch Protools, the speakers starts to give a high pitched hum. This remains constant and only goes away when I close ProTools.

I cannot hear the hum through the headphones.

Can anyone PLEASE help me? I am so annoyed!

[Bookerv12]

Hmmmm.
Are the speakers and interface plugged into the same outlet?
Try plugging computer, interface and speakers to same plug.
See if that fixes it.
If not, ...
Are you using TRS cables to the speakers? (three conductor plugs)
It sounds like noise is being amplified by the speakers.

Can you plug in another piece of gear to the speakers to rule them out as well?

[musicman691]

Originally Posted by Bookerv12

Hmmmm.
Are the speakers and interface plugged into the same outlet?
Try plugging computer, interface and speakers to same plug.
See if that fixes it.
If not, ...
Are you using TRS cables to the speakers? (three conductor plugs)
It sounds like noise is being amplified by the speakers.

Can you plug in another piece of gear to the speakers to rule them out as well?

Could be a ground loop like you're suspecting. Another issue might be the power supply internal to the monitors is humming as it's probably a switcher supply and not the old-fashioned linear supply.

[annapretorius]

Hi there

The speakers and computer are all plugged into the same multiplug.
The fast track sound card is powered through USB.
I am using TRS cables between the speakers and the interface.

[annapretorius]

The hum starts as soon as anything starts that generates sound.

IE: Hum starts when launching ProTools
Hum starts when playing video on quicktime.

[notable]

Is it like white noise? Kind of a hiss that is a background constant and goes up to minorly audible 30dB when you crank your speakers up?


Sent from my iPhone using Tapatalk Pro

[notable]

If yes... I've seen this with noisey power feeding yamaha powered monitors. The solution was power filters on the powercable that fed the monitors and balanced cables feeding the audio to them from the interface. Also test the grounding....One cheap test for grounding issues is trying 50 cent ground lifts on the speaker power cables.


Sent from my iPhone using Tapatalk Pro

[Sardi]

I posted in the other thread but that seems to have disappeared. Perhaps a mod deleted it as it was a duplicate.

If it’s high pitched whine, it’s more than likely coming via the USB bus on your computer. It’s not uncommon unfortunately. Power filters and isolators are what you need to try.

I had it in the past on an iMac and the only thing that totally got rid of it was to lift the ground/earth on the iMac power. Its not recommended for obvious reasons, but I knew the risks and did it as a short term remedy as the USB interface was a stop gap whilst I was deciding on an interface upgrade as I prefer FW.

As mentioned above, lifting the earth on your monitors will achieve the same thing.


Sent from my iPhone using Tapatalk

[musicman691]

Originally Posted by Sardi

I posted in the other thread but that seems to have disappeared. Perhaps a mod deleted it as it was a duplicate.

If it’s high pitched whine, it’s more than likely coming via the USB bus on your computer. It’s not uncommon unfortunately. Power filters and isolators are what you need to try.

I had it in the past on an iMac and the only thing that totally got rid of it was to lift the ground/earth on the iMac power. Its not recommended for obvious reasons, but I knew the risks and did it as a sort term remedy as the USB interface was a short stop gap whilst I was deciding on an interface upgrade as I prefer FW.

As mentioned above, lifting the earth on your monitors will achieve the same thing.


Sent from my iPhone using Tapatalk

And I thought cheesegraters were the only ones that had the USB whine problem? As I remember reading about it it was mainly the USB ports on the front of the computer that had the noise and the others were okay. First I heard about iMacs having that issue.

One of the reasons the USB ports can have noise on them is due to the type of power supply used inside. They use a switch mode type of supply that's basically an oscillator running at a high frequency to regenerate the incoming AC mains. It's one way they can get around having one power supply in all their computers that can run anywheres in the world. All one has to do is to change the plug end that goes into the wall socket (or they give you different power cords).

[annapretorius]

I also tested it on a windows system. When I play anything through the fast track duo and the same monitors, there is no hum. Only happens on the mac.