I have a Firestudio Mobile external sound card which uses the Firewire port, whenever I move the mouse or open a new screen I get a rustling noise from my speakers. It is very annoying, last week I purchased the Focusrite 214 (USB) in the hope that the problem would be cured, alas no such luck, I still get the same rustling noise when windows open or mouse movement. Does anyone have a cure for this.?

Many thanks in anticipation or a solution.

A lot of computers do this and it is mostly the cheap and nasty sound card built into them which also has an unbalanced output.

I managed to cure this by using my blackmagic HD card to output the audio in balanced line level to my digidesign desk which then feeds my monitor amp.

Please describe precisely the audio chain from your computer to your speakers and how they are powered.

Thank you Gary and Jay for your feedback and interest.

Jay,

I have the Presonus Firestudio mobile which uses the Firewire port and the Focusrite Scarlet 2i4 which uses the USB port. I am using the TRS (balanced) connection for my Yamaha monitor speakers. Nothing more complicated than that. The CPU noise happens when I move the mouse or open a window or open a web page with lots of images. If I use the power adapter with the Firestudio then the noise is virtually eliminated, the Focusrite uses power from the USB port.

When you monitor your interfaces from their headphone jacks using good headphones do you also hear the noises from the computer?

Also, where do you have your interfaces located physically in relation to the computer and its monitor?

Hi Jay,

No, both the FireStudio and Focusrite are totally silent with Headphones attached ( Sennheiser HD 25)

The computer is under the desk and the interfaces are approx 4 foot away.

Next I would connect the audio line outputs from the interface to some other audio device like a recorder or a mixer that you can also monitor with headphones. If that's clean then it has to be your speakers or their AC power connection in relation to the computer AC power, or the precise location of the audio cables going into the speakers in physical proximity to your computer or computer monitor.

If that test has noise, then it could be your cables are bad or aren't wired correctly for a balanced connection.

Which Yamaha speakers do you have? And what type of computer monitor?

Jay, I have just had a "Doh" moment and looked at the cables I see that I am using unbalanced jacks, i.e. only two contacts per plug. Do you think using a Balanced TRS cable will cure the problem? or should I be using that anyway? I did think I was using TRS cables as previously stated in an earlier post, I guess we shouldn't always assume without checking first.

Balanced cables are certainly worth a try, it might solve the problem easily.

I have ordered a pair of Balanced cables, will let you know if they cure the problem.

Just FYI, the computer noise could actually be radiated from the monitor or the monitor cable as well as the CPU. Also, not all speakers are well shielded and they could be picking up the RF directly.

I will experiment with the placement of the speakers or monitor and see what happens, I am putting all my hopes into the Balanced cable option, fingers crossed.

The balanced cables option didn't work, just tried them. I also tried putting in a dedicated USB & Firewire card, again not a solution. I am stumped.

What type of computer video monitor do you have?

Do you have any other device you can connect your interface to with your new balanced cables, and monitor that device with headphones to make sure the problem starts happening when the signal reaches your speakers and not before?

I don't know if this would work, it really shouldn't be needed, but plugging your speakers AC power into a line filter like this one:
Gefen GTV-PLC-FEU Power Line Filter - EU Version GTV-PLC-FEU B&H


Can you connect your audio interfaces to your speakers (sitting in the exact same spot) but running from a different computer like a laptop? Then confirm that signal path is clean independently. Next move the mouse and open up some windows on your main computer and listen if that still induces the sound on your independently connected speakers.

I reckon the balanced cables might fix this, however, just out of curiosity, can you give us a little more information as to the computer specs? For instance, do you have a wireless lan card or the like installed? Its rare, but some of the added PCI components can cause the effect you are describing. I've had it happen more than once on different setups.

Also, just to be sure, have you completely turned off the onboard soundcard device? I realize that the firewire likely overrule whichever soundcard you have, but from time to time the onboard card will act up, if not turned off entirely.

Again, I doubt its any of those, but those are easily checked while you wait for the cables to arrive!

Jens, the cables did arrive this morning and they didn't solve the problem, not to worry, I guess I should have used balanced cables anyway. The built in HD soundcard has been disabled via the BIOS control panel. I did try a dedicated USB2 with Firewire card, but this had no effect. I will try the advice that Jay offered later today.

Computer specs are Intel i7 CPU, 16gb RAM, nVidia GX470 cuda enabled card, 2 hard drives, 2 SSD drives, BluRay burner and CD/DVD burner.

I am certain it could be a video driver that is causing the problem as it only occurs when there is action on the screen, mouse movement, windows opening or video playing.

At least you can cross that off the list then! :) I figured you would have done the soundcard thing already, but better safe than sorry!

Drivers are always delicate to diagnose from my experience, although rather easy to test I guess. nvidia recently rolled out a new driver initiative, in which they make it really easy to keep graphic drivers up to date. If memory serves its called GeForce experience. While its mainly aimed for the gaming industry, it does not take up any actual resources, and makes it quite easy to keep everything up to date. It can be found here Drivers - Download NVIDIA Drivers (http://www.nvidia.com/Download/index.aspx?lang=en-us)

All that said, for the purpose of editing video and audio for that matter, I don't think you'll notice much of a difference by keeping the driver up to date per say, other than maybe peace of mind. If you are, however, going to check up on the driver, I suggest you do a clean install of the driver, meaning removing all nvidia driver components before installing. As I said, drivers can be delicate, and if you're just overwriting the previous installation, it may not fix everything, so here is what I would do:

1. Download the newest driver from the above-mentioned link.
2. Go to the control-panel and uninstall everything which says nvidia or geforce
3. Download a program called Ccleaner and run the register cleaner - it'll make sure that the old nvidia references are properly removed from the system
4. Reboot and install the driver you downloaded in step 1!

I should mention that I'm honestly not sure whether or not this will have any effect at all. It is very likely that it may be outside of the computer. I've used a device equal to the one Jay posted, which had great results, but I'm a big fan of testing the computer thoroughly before investing in new hardware!

edit: Another reason for doing this is that the HDMI output of the 470 also have a soundconnection which may or may not have been turned off. In any case, I recently worked on my brothers computer while editing some audio for a friend of mine. I could not, for the love of my life, get the sound level to work properly. It turns out he use the computer for streaming movies on his television as well, and used the HDMI for audio as well, which is smart, but somehow caused the presonus box I used to get confused when to overwrite and when not to. I did not upgrade the driver, but simply turned it off. My point is that software can do the strangest things to the hardware from time to time, and its well worth checking up on before. If for nothing else, then for the heck of it! :)