Aditional Screen Causing Speaker Hum?

Hi Everyone, This is my first post here so please be gentle with me.

I have have been using Logic for about 6 months now after going through all the other popular DAWs in the past 3 years so i would like to think I'm reasonably proficient in understanding the in's and outs of the program.

My problem in this however. I have added an additional monitor i had previously used with my PC to the mini display port via the Apple adapter available. Problem here is that it instantly creates a low hum through my monitor speakers which is very annoying. I've got the Screen which is a 19 inch Chimei on a separate power source to the Speakers and have tried to trouble shoot this over the net without success. All my drivers and software are up to date. Things that effect the hum are as follows.

- the whiter the screen the louder the hum

- Removing the USB fast track Pro and using the onboard sound makes no difference ie the hum remains (please note i would like to keep using my card. An additional fire-wire sound card was tired which also had hum present).

- Additional screens have been tried and the hum is also present with these.

- As soon as the adapter is removed from the laptop the hum stops.

If someone has any ideas on how i can fix this would be most appreciated.

Cheers

Ro

19 inch Chimei on a separate power source to the Speakers

If you haven't already, try putting the monitor on the same mains circuit as the speakers and computer (i.e. on the same power strip).

Sadly, I had this exact same issue with my first MBP. I never did work out what the root cause of it was but I found that by changing out the adapter for a different one the hum lessened but never quite went away.

Unfortunately in one sense, my original MBP was stolen before I could get it over to my nearest Apple store for them to take a 'look see' so after having it replaced under the insurance I noticed, lo and behold, no more hum....

Both of my MBP's were 2007 models.. so it seems to me the issue was related to something not quite right with my first MBP but as to what it was exactly, I cannot say.

However I do have a couple of suggestions...

Try out a different adaptor.

If nothing else the hum might be reduced as it was in my case.

Final option is to take it to your nearest Apple Store / Service center and let them look at it. The reason I suggest this is, even if your MBP is outside of it's warranty, if the issue is related to your graphics card and if it is one of the Nvidia ones that are known to have various issues, they might replace it for you free of charge anyhow because of these known issues with that card.

Good luck!

Check out this thread. It may solve your problem.

http://www.logicprohelp.com/viewtopic.php?t=51544&highlight=mbp+display

The quote below is from the above thread.

Hum gone. I highly highly recommend the HUM X to anyone with similar problems.

Check out this thread. It may solve your problem.

http://www.logicprohelp.com/viewtopic.php?t=51544&highlight=mbp+display

 

The quote below is from the above thread.

Hum gone. I highly highly recommend the HUM X to anyone with similar problems.

this looks like a great product but we have different voltage her in New Zealand and the plugs are different.

I think I'll get hold of someone else with a MBP and plug it in to see if they have the same issue. Then go from there. Other option is to get a sparky in to look at the ground issue.