How to Avoid Mobile Phone Interference w/ Speakers

EnzoTen asks: "Everyone has been sitting at their desk rockin, jamming, or groovin to their favorite tunes. You are in a trance, getting work done... then... BZZZPT... BZZTP..BTT.. BZZZZZZZZPTT... the blood curdling noise of your cell phone interferes with your desktop speakers playing 4 times the volume of your music and it takes everything in you not to flip your desk upside down, or throw your mobile phone across the room. Is there anyway to avoid mobile phones interfering with speakers? Are there speakers available that are shielded from this type of interference?"

Re:Never happened...

[hmhansolo]

happens all the time for me.. the only good thing is, is that if you are paranoid, you'll know when your cellphone talks to the tower.. you won't know what of your private information it is giving away.. but you'll at least know when it gives it away ;)

happens to monitors too

[schweini]

i'm frankly a bit surprised that so many people don't know what you're talking about - i know it very well, and it even affects my monitors.i actually like it -you get to see how long the cell-tower to phone negotiating takes, since it starts happening a couple of seconds before the phone actually rings or receives a SMS.
the solution, i guess, is simply to use more expensive shielded speakers, since that's what faraday cages do.

Re:Um...no.

[croddy]

He probably just replaced his audio cabling. The cable is the giant antenna that's picking up this signal, not the speakers -- and it's probably the signal going into the amplifier that's being distorted by the GSM data bursts.

Cell phones probably aren't powerful enough to cause cancer, but they sure as hell aren't powerful enough to drive a speaker cone from across the room.

But hey, why listen to me? This article by an electronics engineer [edn.com] was just a quick google search away!

Re:Wait, what?

[JabberWokky]

It's the system, not the phone. As has been noted, it's a GSM thing. That means that pretty much any make/model of phone will do it with the GSM variant (assuming there is one for that given model). If you travel quite a bit, it's pretty much your best bet -- some parts of the world only have GSM.

The interference is a clicking, somewhat like a rotary phone (I now feel old). It happens when the phone is talking to the tower. I kind of like it as it occurs a second or so before an incoming call starts ringing. It also occurs at random (or maybe regular?) intervals.

It bugged me with one set of speakers that were arranged such that it was fairly loud. I moved the phone, and it fixed the problem. My new speakers click more subtly, and I don't really mind it. I think it may have more to do with the volume settings on my computer and on the speakers than the brand of the speakers.

--
Evan

It is not just speakers

[PrvtBurrito]

I hear this during press conferences all the time on live tv. It really isn't a bzzz, but more of a repeating, rapid blip-budup-budup-budup... Listen for it, it happens a lot. In san francisco, it used to happen near the cellphone antenna's on my old walkman.

Re:Never happened...

[ergo98]

This happens with amplifiers, speakers, and CRT monitors if the phone is near them when the phone is actively sending data/voice.

If my phone has an active call and I move it near my keyboard, my keyboard stops functioning. Discovered this by chance one day while on hold.

Re:GSM

[DAldredge]

From wikipedia:

"In the 900 MHz band the uplink frequency band is 890-915 MHz, and the downlink frequency band is 935-960 MHz. This 25 MHz bandwidth is subdivided into 124 carrier frequency channels, each spaced 200 kHz apart. Time division multiplexing is used to allow eight speech channels per Radio frequency channel. There are eight burst periods grouped into what is called a TDMA frame. The channel data rate is 270.833 kb/s, and the frame duration is 4.615 ms.

The transmission power in the handset is limited to a maximum of 2 watts in GSM850/900 and 1 watt in GSM1800/1900."

Better speakers fixed it for me

[KingPrad]

I had this problem at work, where I had some cheap $20 speakers I bought at Office Depot or OfficeMax. The buzzing annoyed me so I took the speakers back and bought some $30 ones. Not too much more expensive, but a huge difference in quality. I still put my cell phone in the usual place, right next to the left speaker, but I've never had the buzzing problem since.

At home I tend to put my cell on my desk next to one of the speakers. The speakers are just a $50 2.1 set I bought a few years ago. They've never done the buzzing thing.

So overall, I have only encountered the problem with cheap speakers. Just a slight upgrade made a huge difference, not just with this problem but in sound quality and general sturdiness. Obviously there are a thousand phone models, and mine is just one of them. I thought I'd put my experience out there at least.