My computer speakers turned into a radio??

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caber
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My computer speakers turned into a radio??

Post by caber » Fri Oct 29, 2004 9:22 am

hello all, after silencing my system for a while.. I realized that my system is not silent at all. When I turn on the speakers, I can listen to the news channel at night. If i turn up the volume, I can hear a buzzing sound and each time I move my mouse, the sound buzzes even more. Only solution right now is to turn off the speakers.... :( Can someone please explain this phenomenon?

Speakers: Creative Inspire 5.1
Mouse: Microsoft intellimouse explorer

sthayashi
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Post by sthayashi » Fri Oct 29, 2004 10:55 am

You and I have the same problem, except that my speakers aren't influenced by my mouse at all.

My speakers are generic bookshelf speakers, connected to a Yamaha integrated amp. This itself is connected via 2-RCA cables to a Stereo-Link USB audio device. I noticed that the radio signal becomes a lot weaker when I unplug my headphones from the Stereo-link. Incidentally, the radio station I'm getting is 96.9FM, one of my favorite stations in this area.

Running a wire between the amplifier, case and Stereo-link did nothing. I'm looking for answers here too.

luminous
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Post by luminous » Fri Oct 29, 2004 1:52 pm

I know next to nothing about audio, but I know that these people do: http://www.3dss-forums.com/cgi-bin/wwwt ... ds.pl?Cat=

Perhaps they will be able to help you out if nobody here can.

MikeC
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Post by MikeC » Fri Oct 29, 2004 2:30 pm

The cables to the speakers can act as an antenna. It sometimes happens with stereo systems. Volume control does not change it, right? Try moving the position of the wires and/or speakers. You should hear some differences & maybe get rid of it in a different position.

sthayashi
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Post by sthayashi » Fri Oct 29, 2004 2:52 pm

In my case, volume control DOES change it. And as I mentioned, unplugging my headphones helped.

chylld
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Re: My computer speakers turned into a radio??

Post by chylld » Fri Oct 29, 2004 3:08 pm

caber wrote:each time I move my mouse, the sound buzzes even more.
i had this problem as well with my hardware:
- abit nf7-s motherboard with onboard nforce2 audio
- logitech mx700 mouse
- cambridge soundworks fps2000 4.1 speakers

for me it turns out the problem was entirely to do with the onboard audio (dunno why i listed my mouse and speakers hehe) - the crosstalk on the motherboard between the audio out and the io was the cause of my buzzing. changing to a sound blaster live! value sound card fixed the buzzing.

luminous
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Post by luminous » Fri Oct 29, 2004 3:25 pm

i get buzzing on my machine if the mic in is enabled for my onboard sound card.

I also get buzzing on my headphone output when i move my mouse.

I use an Nforce 2 based board - Asus A7N8X - Deluxe Rev 2

gitto
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Post by gitto » Fri Oct 29, 2004 4:04 pm

ive heard that (magnetically?) shielded cables should stop the interference

hvengel
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Post by hvengel » Fri Oct 29, 2004 5:13 pm

You have something in you audio chain that is not well designed to prevent RFI. Speaker wires and/or other wires leading into the device are acting as an antenna and the RF is getting into the device causing it to act as a radio receiver. This is not an uncommon problem particularly when the radio transmitter is near by or has a very strong signal.

There are several ways that you can possibly improve this.

1. Shield all cables connected to your device. A simple test is to rap aluminum foil around your speaker wires and the head phone wire.

2. Put a low pass RF filter inline with all wires into the device. So in your speaker wires you can wind the speaker wire around an iron core. Radio Shack sells two piece cores just for this. They are cheap and this is easy to do. The bigger the core and the more turns you wind around the core the lower the pass freq. If the problem is a local AM station you will need to use a large core with many turns. For FM you can use a smaller one. Put these as close to the electronics as possible. This will isolate the ¨antenna¨ from the rest of the system by only passing lower freqs. that are too low to let the radio freqs. into the electronics but are high enough to let the audio signal pass.

3. Get better components. Not always feasable and most comsumer electronics are not well designed to prevent RFI problems particularly if the signal you are having a problem with are very strong. In addition it can be difficult to isolate how the RF is getting into your system and you could still have the same problem with your replacement parts.

You might try #1 and/or #2 with your head phones first since this appears to a major source or the RF getting into you system.

Talz
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Post by Talz » Fri Oct 29, 2004 5:21 pm

Gitto is correct, though sometimes the interference can be picked up in the soundcard as well. I can tell a huge difference between my $20 labtecs using onboard sound and my Z-2200's using an Audigy 2 (the latter is much, much less prone to picking up unintended signals).

ActionAttackJohn
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Post by ActionAttackJohn » Fri Oct 29, 2004 6:42 pm

Welcome to the world of craptastic onboard sound.

Buying a proper sound card and speakers will solve most all of your interference problems.

caber
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Post by caber » Sat Oct 30, 2004 12:57 am

Thanks for the help guys... got bad news, it's my subwoofer,

and before I connect any speaker wires into the sub (only the ac power into the sub) then I can listen to the news.... I tried wrapping aluminum foil around the ac power cord but no luck. Trying the radio shack thing next day =) The buzzing sound is related to my bass level. The higher the level, the stronger the buzzing sound.

not too sure if a new sound card can help me out here.... maybe a iron core..??

ecto
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Post by ecto » Sat Oct 30, 2004 3:16 am

I had the same problem as chylld. Onboard audio is plain CRAP. I went from the onboard audio of a ABIT IS7 to a SB Live, and it also solved all of my buzzing problems. And I who bought a mobo with integrated audio to get rid of a PCI card.. I know now that's never going to happen.

Rusk
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Post by Rusk » Sat Oct 30, 2004 4:51 am

As I was reading through this I was wondering if it might be the subwoofer. Finally, I got to your post where you said it was the subwoofer.

I believe that what is happening is that the power supply and the amplifier in your subwoofer are working together to pick up the radio signals. These subwoofers are not all that large, and they have to cram a lot in them. And these speakers are not all that expensive. Another issue is that a lot of these speakers use Class D amplifiers. They are very efficient but prone to high frequency (radio frequency) interference. They are simply switching amplifiers--Pulse Width Modulation amplifers--switching on and off. This is really what computers do. Therefore, you could have an additional problem if your computer is putting out spurious noises.

The USB bus can cause problems sometimes too. Very often they are noisy, which is why they are not always a good choice for audio. Again, a lot of it depends on your motherboard. Some of them have well-shielded USB ports and some don't.

Also, Wi-Fi can cause interence. And cordless phones can too. You might want to check all of them out.

Try this: Try taking your speakers off your computer and connecting them to a portable CD player in another part of your house. See if that makes a difference.

Some possible remedies:

Using the ferrite beads mentioned above. These are donut shaped pieces of ferrite that you can find at Radio Shack for 40 cents a piece or less. Try them in different places.

Try plugging your speakers and computers in different outlets. Even moving them to different plugs on the same outlet can make a difference.

If you have a good quality surge protector, move your speaker plug to the outlets farthest away from where the surge protectors power cord enters the surge protector. The last outlest usually provide a greater degree of RFI rejection.

Make sure you have a good quality surge protection--one with good RFI rejection. The specs on the boxe will usually indicate how much RFI rejection it offers. Look for at least 65 db, with 75 db being about the best.

Move your cordless phones and Wi-Fi equipment around. Sometimes this can solve the problem.

Your lamps both incandescent and fluorescent could be emitting RFI. You can check them out by tuning into interstation hiss on an AM station on a handheld radio. Movie the radio and around the light, and if you hear noise, that could be the problem.

I hope this helps.

Regards,
Last edited by Rusk on Sat Nov 06, 2004 2:10 am, edited 2 times in total.

caber
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Post by caber » Sat Oct 30, 2004 10:04 am

Wow very informative, thanks!

i dont have any wi-fi equipment, but I do live in a town home area so my neigbours might have em...

I do have a surge protector, and i wasusing the furthest outlet beofre. Not too sure about the RF rejection, it is a apc surge (no ups).

Think it might be my lamp? because when i do turn it on, my subs make a boom sound. perhaps I should sperate those 2 ac outlets... *crosses fingers*.

Motherboard wise, I am using a gigabyte-Pe1000. Can not confirm about usb ports being shielded or not. I am not using any.

Tried moving the sub futher away from the wall and when i moved 1 feet away, the radio sound is subdued. However, buzzing sound still exists, and the problem is with my onboard sound port. Each time I plug or unplug my speaker plugs the buzzing sound is tthere... might get a sb audigy. Anyone here have any recomendations? Thanks guys!

hvengel
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Post by hvengel » Sat Oct 30, 2004 3:52 pm

Since you have isolated the ¨buzz¨ (I think hum is the correct term assuming it is 60Hz) to your sound output from your mother board a better sound card should help this out.

My step son just got a M-Audio Revolution 7.1 and he really likes it and says it is way better than the Audigy he replaced. This same basic card is also available as a 5.1 card for a little less $. M-Audio definitely has better analog sections in thier cards than Creative does and price wise these cards are in about the same price range as the Audigy cards.

If your sub is acting as a radio when the only thing it is plugged into is the AC power then it is likely that your power cord and/or house wiring are acting as an antenna. Is the problem station AM for FM? If it is AM it is likely that the house wiring is implicated since AM has fairly long wave lengths (>300 meters) and FM is fairly short (about 3 meters) and an optimized AM antenna needs to be fairly long (>75 meters). But it is also possible that there is something internal to the sub that is acting like an antenna. Try ferrite beads on you power cord (remember put them close to the sub) and this will isolate the sub from your power line/house wiring. If it is still doing it then the problem is likely interal to the subs power supply and/or amp and the problem will be harder to fix. At that point you could rap the sub in foil to see if that has any impact on the problem. Since it got better when you moved it away from the wall it sounds like you were getting some kind of coupling between the sub and your house wiring when the sub is close to the wall. You might also try changing the direction that the unit is facing since radio waves are directional and also have polarity (try turing the unit on it´s side).

Rusk
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Post by Rusk » Sat Nov 06, 2004 2:04 am

I agree with hvengel that the subwoofer might be interacting with your house wiring and could be picking up AM signals that are in the wiring. Glad to hear that it has gotten a lot better and hope that you resolve the remainder of the noise coming out of your speakers.

Regards,

lm
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Post by lm » Sat Nov 06, 2004 3:21 am

Having a soundcard that supports digital output and an amp that can take optical input, then connecting the computer to the amp with optical fiber, will completely eliminate any interferences to the sound output made by the computer. It's a good idea in many ways.

For example the soundstorm in nforce2 can do this, and so you don't have to ban integrated cards.

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