My coworker's cingular phone sends a lot of interference. My speakers start making weird noises a second or two before she gets a call. It's annoying.

Yet my T-Mobile phone sits right by my speakers but it doesn't affect them.

Here's the boilerplate warning about interference:

"This device complies with part 15 of the FCC rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) This device must accept any interference received, including interference that may cause undesired operation."

So if he can prove that his phone put out the interference, then he may be able to get restitution. This also lets the speaker manufacturer off the hook.

For the record, Cingular isn't really in the phone making business, they provide cell phone service. ANY cell company can have interferrence issues. (And they all do.)

Also, it's the guy's AMPLIFIER that makes the signal stronger, not the phone. He must have had it turned up pretty loud and the phone very clmTIM/VAP

Pasketti posted what I was going to post. FCC passed his phone, therefore his stereo should be able to deal with it.

My Cingular phone always does that. I like to listen to music really loud in the car, and every so often it'll be like "BZZZT bzzt BZ-ZZZZT bzzt BZ-ZZZZT" and I'll almost drive off the road and then I'll be like "Damn you, cell phone force field! You've crossed me for the last time!" I hate it so much. Oh well, too bad I'm switching from my family's plan with Cingular to my very own plan in a month. Cingular can bite me.

My motorola phone (iDEN) on Nextel would do exactly the same thing.

I spent hours troubleshooting my speakers - I first thought it was my computer, so I unhooked em.
They still made the sound every once in a while, so I thought they were bad - no biggie, bought another set.
Same damn noise!
Okay, maybe there is something odd with the 120v in this house - bought a circuit isolator.
STILL THE DAMN CLICKCLICKclickclickCLICK noise!

Finally figured out it was the damn phone in my pocket. Grr.

From a technical standpoint it seems difficult to swallow that the bzztbzzt was the sole cause of the lamented blown-speaker. From an artistic standpoint that's an awesome video!

That buzzing RF noise is a documented feature of the GSM call protocol. I think the output strength depends on the particular handset you're using.

[forum with an overview]

http://www.blackberryforums.com/hardware-accessories/7813-...

Sorry to hear this fellow had his phone near an unshielded amplifier input; I've gotten pretty loud feedback over some of my less expensive wiring to unamplified speakers when i have mine sitting parallel and on top of them.

:(

as said before, it's not just cingular phones. My office 'neighbor' has a nextel phone that gives out the same interference mine does (our landline phones pick it up anytime it rings) as does my other 'neighbors' alltell phone.

cingular doesn't build phones!

If I'm not mistaken, it has to do with the fact that it was either GSM service or a different frequency than what older cell phones were. When I was in Australia, you could always tell when someone's phone was going to ring because the TV or radio would make that ticking noise, about 2 seconds later someone's phone would ring. Nothing new there.

Yeah as much as I love my Cingular 8525 the one problem with it is that it puts out more RF interference than any phone I've ever owned before. I can't have it on my desk it interferes with my PC's speakers. I can't have it in certain spots on our couch at home... it interferes with the TV's speakers.

The worst RF leakage I've ever seen in a phone.

I've had the same issue with my Cingular phone. I had a Nokia at the time (one of the cheapo kind). At home I would always hear that weird sound right before the phone rang over my computer speakers, and there would also be an occasional weird repetitive beeping (on a very specific rhthym) every few hours if the phone was near the speakers.

It would also happen at other people's houses... and at K-mart when I was walking through the stereo section.

It quit when I upgraded to a Samsung slider phone.

I don't think cell phones are "Part 15" devices. The home reciever is, however.

All GSM phones do this to some extent.

@DarienA:

It's not really RF leakage. Cell phones are radio transceivers; if you build one that doesn't 'leak' RF, it won't be very useful. This is more the fault of the speaker/amplifier manufacturers (who don't seem to have provided adequate shielding for the audio signal lines) than anyone else.

Speaker damage can be caused by high-power signals with sharp-edged waveforms (square waves, clipped sine waves, and so forth - the extremely sharp voltage transients fight the inertia of the speaker cone, causing it to tear.) My guess is that Justin's phone induced a fairly loud signal at the input of the speaker amp, which was then badly clipped and fed to the speakers. This sucks, but it's far from unheard of - and he may have no recourse since the speakers are Part 15.

Yeah, I'm fairly certain it has something to do with the GSM standard. When I worked in an office in the UK it happened a great deal, but I can't say which operators did it. Still, if davere's right and T-Mobile is unaffected, either TM is using a different frequency, or Cingular does have some weird glitch that a large number of Uk operators all suffer from as well.

This would be due to very poorly-shielded audio equipment if that's really the case. I suspect, however, that we're not getting the whole story. Its a shame this guy busted a speaker, but its not Cingular's fault. Nice work with the site and the animation though -- too bad its just misplaced anger.

I am no fan of Cingular but I don't see their fault in this matter.

The signal output power and frequency is likely the same as any other GSM phone, correct? Perhaps the manufacturer of the phone used a higher-power transmitter? The GSM specifications likely have an acceptable range of transmitter power output. If the manufacturer designed the phone outside of any specified parameters then I can see some blame directed at them.

My Nextel (Motorola) phones used to do this too. I never could figure it out.

But my Verizon (Motorola) phones have never done this. It might be the frequency they use. But true, very very annoying.

I would have the phone on silent when I went to bed, and my computer speakers would alwasy be on and they would start making that noise. They should probably work on fixing that.

By the way, yes its not cingular that makes the phones. But they do support them and put their logo. So you should therefore be providing good equipment...

Is anyone watching the video?

My wifes Cingular phone makes the stock radio in her Camry go nuts! Not only when getting a call though also when you enter rural areas or change cells. Its sad she has to turn off the phone when driving otherwise you get this blaring morse code sounding crap blaring through the car speakers.

@CaptainRoin: I think it's because of how GSM phones work. My last hearing aid suffered horribly from this when ANY GSM phone was near it, so until I got the aid I have now I had to stick with CDMA. I have Cingular now and my phone buzzes when near my computer speakers, so I just turn the speakers off if someone calls when I'm playing City of Heroes. I don't need sound for that.

@Pasketti: Thats assuming the device was within tolerances. Remember the FCC doesn't test every device leaving a factory. A design is only as good as its manufacturing tolerances.

@Jaideepg: Verizon phones are CDMA, not GSM, and CDMA works differently (in such a way as to not make noise).

It's not quite interference... The speaker is picking up, and is being induced by the actual GSM signal. GSM uses time based division of the spectrum - this is what allows multiple people to use a cellphone on the same carrier band (the 850/1800 Mhz thing). Time based means that your phone can send/receive data for say, only 1 out of every 10 ticks of a timer. Other phones send on the other 9 ticks. The speaker is not sensitive to the carrier band's frequency, but it is sensitive to the lower frequency when your phone sends, then doesn't send, sends, doesn't send etc. This time divided signal looks kind of like a square wave, which is just what could possibly break a fancy speaker. The clicking is more prevalent on incoming calls because of the higher power used at the beginning of the call.

To stop this,you would have to use a time division that divided signals faster then the speakers response, which would be >30kHz, or stop using time divided signals all together. There are difficulties in implementing both of these ideas.

This interaction is not present on Sprint/Verizon phones because they use CDMA, or code based division, which means every phone sends at the same time as every other phone, and fancy math figures out who sent what. (GSM also uses frequency division to separate towers.. so one tower will be 1830.5 Mhz, and another will be 1828 Mhz).

Wikipedia has some great articles on CDMA, GSM, TDMA, and FDMA if you're interested in learning more.

Happens to me all the time. With my old Samsung phone with Cingular it would happen constantly even if the phone wasn't ringing. Wrapping the phone with my hand or something else would cause it to quite some. I recently got a new LG phone still with Cingular and the problem still occurs, but thankfully much less then the old Samsung phone.

We are all talking on miniature microwave ovens, and we are amazed when they interfere with electronic equipment? Fact is that all cell phones have microwaves being sent and received, and depending on the exact frequency being used, they can interfere with just about any electronic equipment.

if it can blow a speaker, i wonder what its doing to your brain cells?!

(my old motorola i530 does this. people think its strange when i answer my phone before it ever rings. . .)

(1) This device may not cause harmful interference

That means "Your license to use this device does not permit you to cause harmful interference", not "This device is incapable of causing harmful interference".

That's why it's a condition of operation. (You are the operator of the device.)

its really more of the speaker manufactures fault. the speakers were obviously poorly shielded. this seems to be happening more and more these days, even some brands of expensive speakers lack good shielding.

They must have been turned up way too loud as well, i have a pair of speakers that does this as well, but it has never caused any problems.

I'm pretty sure most speakers are designed to accept interference, under FCC Part 15, the same regulations that allows most IPod FM transmitters, etc., to operate without any end-user licensing. Wouldn't think it'd be enough to blow a speaker, but who knows. I'm saving up for a pair of studio monitors, though, so I know I'd pitch a fit if they ate it as a result of my cell-phone.

Living near an airfield, speakers will sometimes be actuated with radio traffic. Here at the office, there's a phantom signal that'll come through once or twice a month, still haven't tracked it down to exactly what it is, as it'll hit multiple speakers, but only for a split second. The glory that is radio.

This happens all the time in my studio. i got a really expensive set of genelecs, and it still happens. Theres a good post on gearslutz about it.

velocipenguin and Monty are correct, this is a standard part of GSM specifically, specifically the TDMA signal.

Faulting the phone for generating EM radiation is like faulting a microwave for generating microwaves. That's what it does. The amp/speakers need to properly shielded to avoid this coupling. Operating the amplifier unshielded with a high enough gain to damage the speakers is Justin's mistake, not Cingular's.

Inductance for the win. That buzz you guys hear when near speakers or the like (lcd and crts as well, even without speakers) if from the coils and wires being induced by the cell phone. The closer the phone is to a wire or speaker, the stronger the inductance. Coax cables are mostly immune to it because of the way the cable is designed.

It's the same inductance that is used to make those led flashers that go off when you get a call, like this one: http://cgi.ebay.com/CELL-PHONE-BUDDY-LED-FLASHING-LIGHT-FL...

And I for one use this on my phone to get a call. I place it right by my speaker cable so that even if its on vibrate because I forgot to switch it after work or class, I can still hear it.

Oh, and as a side note, cellphone companies should be held liable for the phones they sell. Manufactures cater to them in design specs and custom (and mostly user disabling) firmwares, and they use them to make a profit. If you're going to slap your name on something and prevent people from using it on other services, you should be as liable as the manufacturer. Even more so since the customer deals with you directly and only has a third party relationship with the manufacturer.

So...is there an easy-ish way to limit cell-to-speaker interference? Besides turning one or the other off, that is.

@BareFeet: Shielded cables, shielded speakers, an well designed amp...

Easiest is keep your cellphone away from your computer and stereo.

man, the only thing that would have made it funnier is if they had included the Cingular dude creating somesort of honeybee holocaust. heh.

If I have my Cingular 8125 on my desk at home on the right side, it will click my mouse buttons for me. That took me a while to figure out. Also, it pushes the buttons on my PS2 controller. I noticed while watching a DVD with it and it started flipping out, my phone was right next to the controller on the side table. I moved it and everything was fine.

@Buran: what aid are you using now? I wasn't able to even use a modern cell phone until I got my current aid (Oticon Tego Pro P.) I still hear the distinctive GSM buzz every so often but *not* when I'm using the phone. Go figure. Modern digital hearing aids, like modern call phones, are pretty close to black magic.

i use a white noise machine from Brookstone to block out my boyfriend's snoring at night. if i leave my cell phone turned on and it's near the white noise machine, it's make the buzzing noise so loud that it wakes both of us up. it also buzzes my stereo speakers at work, certain landline phones. it's REALLY annoying. this is the first i've heard that it's a known issue. and yes, i'm with Cingular.

That animation is sooo cool. I felt so bad for the speaker that was left. awww, poor speakers!!

Clever bit with the apple logo being one of the eyes of the cingular logo.

Not really related, but they referenced this noise in the 2005 movie version of The Hitchhiker's Guide to the Galaxy, when Arthur's phone is flying towards the camera. That was pretty clever.

That video is awesome!

Its really powerful interference.......
I was transferring some sound tapes to my computer and after i was done, i noticed that my wav files were peppered with gsm interference....i dont know if they go through wires, or magnetic heads....or what...but gsm creates havoc on unshielded equipment.

If the equipment is properly shielded, then nothing happens...

So basically, i had to retransfere all the tapes with the phone turned off and the battery removed.

@cde: For sure.

T Mobile models do this too. It's just a fact of life with GSM. I play in a band and three of us have RAZRs with different GSM providers and if we don't turn them off you hear it through the guitar amps, the PA amps, and the monitors.

Now I am not sure how he damaged it... I have had a 600W power amp running into an Ampeg SVT8x10 with the "click-beep-buzz" sounds (I too use Cingular, BTW), but the speakers work fine. Doesn't sound half as bad as when someone turns off the preamp before the power amp.

@fhic: Phonak Savia. I was pleasantly surprised when formerly-unusable GSM phones didn't make any unwanted noises!

@jurgis:

I use T-Mobile btw. Moto V-360, the fat, microsd verion of the Razr.

Given the number of times I've been on conference calls and had cell phone interference irritate everyone, I'm surprised Sprint and Verizon don't use the interference as a marketing differentiator (assuming that the CW is correct in that it's a GSM-specific issue).

The video was excellent. I don't see any liability issue here, though. The phone is an RF device and as such is given an FCC type acceptance, which means it meets minimum RF radiation guidelines. The phone doesn't put enough RF to damage a speaker by itself, but the RF signal could get into an unshielded or poorly shielded amplifier and drive the amplifier to full volume.

Almost all audio amplifiers are controlled at the low-level stage, and if RF happens to enter the circuit after the volume control, again, it might very well drive the amplifier to full output and damaging the speakers. It could also cause the amplifier to oscillate, thus damaging the amplifier. Anything that radiates RF energy has the potential to do this.

From the Wikipedia entry on "GSM."

A nearby GSM handset is usually the source of the "dit dit dit, dit dit dit, dit dit dit" signal that can be heard from time to time on home stereo systems, televisions, computers, and personal music devices. When these audio devices are in the near field of the GSM handset, the radio signal is strong enough that the solid state amplifiers in the audio chain function as a detector. The clicking noise itself represents the power bursts that carry the TDMA signal. These signals have been known to interfere with other electronic devices, such as car stereos and portable audio players. This is a form of RFI, and could be mitigated or eliminated by use of additional shielding and/or bypass capacitors in these audio devices, however, the increased cost of doing so is difficult for a designer to justify.

That's pretty much it in a nutshell. Your phone is a miniature transmitter and it puts out RF energy which can get into other devices. GSM uses a single frequency with multiple time slots, while CDMA uses spread spectrum which is less likely to interfere with consumer devices. Consumer electronics manufacturers skimp on the shielding for stereos, computers, and TV's because it costs them extra to build into their product.

My fone's unlocked so if I'm on T-Mobile, I dont have a problem with putting my fone next to a speaker but the moment I switch the provider to Cingular or Alltel, those really annoying loud gitgitgit sound bursts thru the speakers.

My phone automatically switches providers if my T-Mo reception is weak (esp in rural areas).