Advertisement
so i just hooked up my new monitor speakers today, and i can hear some faint static coupled with an equally faint high pitched whine which the speakers seem to be picking up from my laptop (i conclude this because, when i shut the laptop off, the noise stops).
i tried moving the laptop a few feet back, but it's still there.
is this some kind of grounding issue?
any suggestions?
thanks!
posted by:
|
Vancouver
|
Advertisement
Advertisement
-
Re: squealing speakers?
Sat, August 4, 2007 - 12:18 AMwhat kind of sound card do you have? -
-
Re: squealing speakers?
Sat, August 4, 2007 - 10:06 AMhmmm.....it's the one that came stock in my iBook G4.....could this be the issue?
the sound goes away when i unplug the firewire cable going from my computer to the pro tools rack unit,
but it's still there if i just *turn off* the pro tools rack
so, it seems to be picking up the noise, not through the air, but through the cable-->PT rack-->speakers
chain, even when the rack's circuitry is not powered on.
?? -
-
Re: squealing speakers?
Sat, August 4, 2007 - 10:32 AMIt sounds like a possible ground loop to me. Are all pieces of gear plugged into the same outlet? -
-
Re: squealing speakers?
Sat, August 4, 2007 - 10:37 AMyes - indirectly (a power bar) -
-
Re: squealing speakers?
Sat, August 4, 2007 - 12:48 PMSo, they computer and all gear is plugged into a power bar that is then plugged into one outlet? -
-
Re: squealing speakers?
Sat, August 4, 2007 - 1:46 PMAre you listening at very loud volume with no music playing?
If so, you may be hearing the noise floor of the device. Every device has some noise, but at normal levels with sound recordings, the noise is not audible.
I have gone into super analytic mode a few times because of this phenomenon.... and then realized that this is normal to have machine noise.
-
-
-
-
Re: squealing speakers?
Sat, August 4, 2007 - 2:37 PMPowerPC Macs are notorious to have sound issues that aren't ground related. Specifically the iBook G4/PowerBooks have this issue the most. You might have to download a package from Apple called CHUD Tools (developer.apple.com/tools/download/). Once you install that program, you'll have a new option in your Preferences called Processor. Within there, you need to disable the NAP feature. If you still have static/high pitched whine, then its power related and not computer related. -
-
Re: squealing speakers?
Sat, August 4, 2007 - 3:51 PMyes - all items are going into a powerbar, and the powerbar is plugged into the wall.
i don't think this is typical for ground floor noise - not only am i listening at low levels, i can hear it when the speaker volume (sent from the rack unit) is at '0'
i will give the CHUD tools a try - thanks! -
-
Re: squealing speakers?
Sat, August 4, 2007 - 5:31 PMTesting for a ground loop is trivially easy in your case. Since it's an iBook, remove the power and run it off batteries. If the whine is still there, it's not a ground loop.
This will be a useful experiment,. Still, I am guessing (with the help of my trusty crystal ball) that what's really going on is that you're running up against the noise floor of your laptop's integrated audio hardware, as someone else has already hyptheisized. It may turn out that you'll need to go with an external firewire or USB audio interface. -
-
Re: squealing speakers?
Sat, August 4, 2007 - 5:38 PM
thanks so much everyone for all the assistance - it's really helping me out over here.
i have tried unplugging everything but the speakers, and the noise is still there. i even tried plugging things into different wall sockets - no fix.
the only thing that makes the noise go away is if i unplug the firewire cable from the laptop, or if i put the laptop to sleep/shut it off.
since i can't afford an external interface, i suppose i'll just accept the noise as best i can.
: ) -
-
Re: squealing speakers?
Sat, August 4, 2007 - 5:48 PMI'd definitely try the CHUD tools. It looks like its cross talk from the firewire bus to the audio bus in the laptop. -
-
Re: squealing speakers?
Sat, August 4, 2007 - 5:53 PM
i forgot to mention - i installed the CHUD tools and did as you suggested, disabling 'NAP,' but alas, the sound persists... -
-
This is the maximum depth. Additional responses will not be threaded.
Re: squealing speakers?
Sat, August 4, 2007 - 6:39 PMSo next out of curiosity, how long is your firewire cable? How long is your audio cable? How do you have them positioned? Are they side-by-side or running on separate sides of the desk? Have you tried using a different firewire cable? -
-
Re: squealing speakers?
Sat, August 4, 2007 - 7:05 PMmy firewire cable is about 5ft....by audio cable, do you mean the two cables exiting the pro tools rack and entering the two monitors? if so, they are each 5ft and quite far from the firewire cable.
i have not tried another firewire cable - i'll see if i can get ahold of one.
thanks again!
-
-
-
-
-
-
-
-
-
