Forgot your password?
typodupeerror

How to Avoid Mobile Phone Interference w/ Speakers 228

Posted by Cliff
from the nextel-phones-are-the-worst dept.
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?"
This discussion has been archived. No new comments can be posted.

How to Avoid Mobile Phone Interference w/ Speakers

Comments Filter:
  • by BrookHarty (9119)
    Move your phone to the floor or behind you, i find 2 feet away from the speakers works.
    When I'm in the car, I dont put my phone in the phone holder anymore, I put it on the seat next to me.

    Also dont put it next to your alarm clock, thats a bitch to be woken up to that BZZZT screech.
  • Simple (Score:2, Informative)

    by Anonymous Coward
    Turn off your cell phone. :-)
    • Or alternately, turn off your speakers.
      • Re:Simple (Score:4, Funny)

        by fm6 (162816) on Friday April 07, 2006 @08:20PM (#15088872) Homepage Journal
        To really solve the problem once and for all, poke out your eardrums!
        • Re:Simple (Score:5, Funny)

          by dotgain (630123) on Friday April 07, 2006 @08:32PM (#15088923) Homepage Journal
          Let me guess, you guys write KB articles for Microsoft.

          Symptom: When you use X, Y doesn't work properly.
          Cause: Due to a design deficiency in X, Y sucks when used in conjunction with X.
          Solutions:

          1. Don't use X
          2. Don't use Y
          3. Render yourself unable to notice the problem
          Keywords: omg bzzt bzzzzz
          • by fm6 (162816)
            Actually, I happen to think that whoever writes those KB articles is pretty good at their job. I've done that kind of work myself, and the point is to educate people about problems, solutions, and workaround, and do so clearly, precisely, and concisely. All of which these guys are quite good at. Which is, alas, more than can be said of most tech writing, at Microsoft and elsewhere.

            Of course, when you work for Microsoft, the problems are often lame, the solutions often don't exist, and the workarounds ofte

      • Re:Simple (Score:3, Insightful)

        by Hes Nikke (237581)
        that doesn't work, my cell phone will drive speakers that are off, unpowered, and unplugged... try again next time!
        • Actually, I forgot that this happens even when the speakers are turned off. It's been awhile since I had a cellphone that did this. On the other hand, my current cellphone causes my alarm clock to make a very very faint high pitched beeping sound when it's plugged in to charge (I can sometimes hear it when it's totally quiet at night and my head is near the clock).
    • I think it's the Nextel Blackberry's that are the biggest violator here. I have multiple cell phones (yes, a few); and I can always tell when the Nextel Blackberry is about to ring because I hear the buzz on my speakers before it rings.

      What providers are you using? What phone?

  • I've used a number of cell phones near many different sets of speakers over the years and have never encountered this problem.

    What model phone/speakers do you use? I'll have to remember to avoid them.
    • Re:Wait, what? (Score:3, Interesting)

      by JabberWokky (19442)
      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 r

      • My old TDMA phones did it as well.

        Nextels do it as well, but the sounds is more like tssh tssh tssh tsssssssh tssh tssh tssh (longer when transmitting voice, shorter when transmitting silence).

        On the plus side, you always knew when your phone was about to ring because the buzzing would become more intense and increase in duration.
        • Just to confirm, every one of my previous employer's TDMA (800mhz band) phones would cause speaker pops within 3 feet, this ranges from nokia 2250's through 9200's to moto v60t and v120t's, not to mention various audiovox, kyocera, samsung, etc. The CDMA phones seem to be a little better behaved (850 and 1800mhz ), they only had to be within one foot of our bone stock dell speakers.
    • The problem is not unpowered speakers. The RF from the phone can't impart enough power into the wiring to drive the speakers.

      The problem is power amplifiers. You only need a small amount of RF to get on the low level signal lines and bam; it gets amplified. The thing with digital phones is that because they're a pulsed TDM signal there is energy (minimal) right down to DC which gets picked up, "demodulated" and amplified in your power amplifier.

      The solution is keep your damned phone away from anything wi
      • In flash memory? Are you sure? That sounds rather bad actually, a flash chip just died on me recently without me using it much, I was wondering why...
      • Wait a minute, cellphones have flash memory of their own that's going to be constantly bathed in the RF emitting from the antenna just a few inches from them whenever the phone is on. I've never heard of a cellphone's memory erasing or corrupting itself, so I call bogus.
    • Happens to me with my Cingular Motorola v180 when close to the speakers Dell sent with my Precision 340 workstation computer. I just put the phone on the back counter instead of under the monitor.
  • Sheesh. (Score:2, Informative)

    by Reeses (5069)
    Sounds like you're getting Electromagnetic Interference (EMI) or Radio Frequency Interference (RFI).

    Both are the result of either bad or cheap shielding. Most consumer electronic devices should have at least some shielding.

    Look for frayed speaker wires. Look for cracks in your cell phone case (the one it's made out of, not the cool "leather" one you got when you bought it).

    Either get new speakers, or replace your cell phone. Or both.
    • Re:Sheesh. (Score:2, Informative)

      by onemorehour (162028)
      Heh, no, don't look for cracks on your cell phone. Your cell phone is functioning properly when it's emitting lots of electromagnetic waves--it doesn't have to be cracked in order to do so.

      The issue is shielding--most likely in the wires to your speakers, but potentially in the power cord or the guts of the machine producing the signal out. If there's terrible internal shielding, dirty power or the EMI on the circuit board itself can cause this.
    • It happened to me also when I owned a Nokia 6120 and placed it on my PC desk. Of course my the speaker wires were not a twisted pair and totally unshilded. Typical for PC speakers.
    • Most consumer electronic devices should have at least some shielding.
      "Should" being the important word. Most companies will gladly sell you utter shite if it will save them US$0.005 per unit in manufacturing cost.
  • GSM (Score:5, Insightful)

    by Detritus (11846) on Friday April 07, 2006 @07:55PM (#15088768) Homepage
    It seems to largely be a problem with GSM handsets, so users of handsets that comply with other standards may not notice a problem. GSM uses TDMA, and has also been noted for interference to hearing aids.

    The solution is to properly shield the speakers and speaker wire. The speaker wire behaves like an antenna, coupling the signal into the audio amplifier, where it is detected and amplified. It's behaving like a crystal radio, a primitive type of AM radio receiver.

  • by schweini (607711) on Friday April 07, 2006 @07:55PM (#15088769)
    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.
    • by mcbridematt (544099) on Friday April 07, 2006 @08:11PM (#15088844) Homepage Journal
      Just about everyone in Australia with a mobile phone (CDMA never took off here) has heard this sound.

      Some phones seem to be worse than others. My Treo 600 is notorious for causing problems with CRT's, while lower end phones aren't.
    • I've never had a problem with my speakers, but I have noticed the monitor thing. One day a heck of a long time ago I had my cell on and sitting right next to (almost under) my CRT monitor. I was plugging along for a little while, when suddenly the image on my CRT started to warp slightly. My first thought was "what the...?" my second thought was "but this monitor is only like 8 months old!" and then... my cell phone rang. Queue lightbulb above the head. It was kind of a neat warning actually, since it happe
  • Yeah, this ALWAYS used to happen to me when I had a Nextel phone, circa 1999 or so -- it was particularly bad with some car stereos. I've heard it ocasionally with various GSM phones, but always with cheap cheap cheap electronic radios, and never as loud as the signal from the old nextel. Basically, I'd suggest trying a different phone (if you're using a GSM phone and can swap the SIM) or a better set of speakers, as it really does seem to be device dependent (unless we're talking the old nextel phones --
  • by subreality (157447) on Friday April 07, 2006 @08:01PM (#15088798)
    There are two places you can solve this problem:

    #1, get a better cell phone. With TDMA phones (GSM, D-AMPS, iDEN) you get a lot of noise as the transceiver switches on and off several times a second, transmitting at full power. iDEN phones (NexTel) have always been *by far* the worst about this, in my experience. If you get a CDMA phone (eg, Verizon), the phones on a cell share a common, continuous, low-level signal, which does not cause this kind of interference.

    #2, shield your amplifier. (In cheap computer speakers, it's built into one of the speakers, or the subwoofer.) Surround it in tin foil, and ground the foil. Other possibilities are poor grounding on the signal wire - replace it with a shielded wire, and ground the shield to your computer's case and where it reaches the amp.
    • #1, get a better cell phone. With TDMA phones (GSM, D-AMPS, iDEN) you get a lot of noise as the transceiver switches on and off several times a second, transmitting at full power. iDEN phones (NexTel) have always been *by far* the worst about this, in my experience. If you get a CDMA phone (eg, Verizon), the phones on a cell share a common, continuous, low-level signal, which does not cause this kind of interference.

      While I'm there are differences in the amount of audible interference on speakers between th
  • I know exactly what your talking about, it happens all the time to my at school, the PCs we have have non-shielded speakers.

    But...I just realized, it never happens at home. I have a set of 5 year old Klipsch 2.1 Speakers, that I would assume have better than normal shielding.
  • I like it (Score:4, Informative)

    by RalphSleigh (899929) on Friday April 07, 2006 @08:09PM (#15088834) Homepage
    90% of the time it happens just before I get a call/text, so I quite like the early warning.
  • by PrvtBurrito (557287) on Friday April 07, 2006 @08:10PM (#15088836)
    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.
  • Easy (Score:3, Funny)

    by Feanturi (99866) on Friday April 07, 2006 @08:11PM (#15088841)
    Just wrap your cellphone in several layers of tinfoil. Problem solved.
  • Speakers (Score:3, Informative)

    by Jeff DeMaagd (2015) on Friday April 07, 2006 @08:17PM (#15088864) Homepage Journal
    There a few different paths you might take. You don't say anything about the model or brand of speakers, that seems to make a difference. The cheaper ones might have insubstantial cable shielding at best.

    My home computer is connected to a reciever that powers separate speakers, I don't really get any problems.

    If you were really obsessed, you might get a higher end sound card with balanced audio out, with powered speakers with balanced inputs. If you have cheaper speakers with cheap built-in amps, then the long, unbalanced cable can act as an antenna. I've found that switching to balanced audio connections is the best way to minimize picking up stray noise on the analog, much better than getting "high end" RCA cables. Switching to XLR (balanced) cables drops the amount of noise significantly in just about any analog audio path.

    Or you could switch to speakers that have a digital inputs. That's probably a lot cheaper to get into.
  • From WikiBooks:Cingular Wireless FAQ#What's that Buzzing in my Speakers? [wikibooks.org] we have a non-answer:

    GSM radio transmissions, particularly control signals (e.g., periodic mobile device registration, SMS message transmission), can induce audible interference (buzzing) in nearby speakers. (Hearing aids can also be affected.) The general issue of radio frequency interference (RFI) [wikipedia.org] is exacerbated by the short pulsing nature of these time division multiplexed [wikipedia.org] transmissions. The most straightforward solution is to sep

    • I mentioned that my solution was to keep distance between phone and speakers ... this is the common response. It is only half of my solution (oops, should have paused after proof-reading the preview) ...

      The speaker buzzing on my system is louder when the speakers are set to a higher volume. Therefore, I have my computer set to output at maximum volume (Wav/PCM and Master channels at 100%) and my speakers are set very low. The result is that there are still buzzes, but they aren't loud enough to give he

    • It's a protocol and modulation suite that happens to include a defined codec, often referred to simply as the "GSM codec", since it is the codec used by the GSM suite.
  • I do get the problem with my speakers at work; generally when someone walks past with a cell phone, sometimes from my own.

    I also have problems with ticking sound on my headphones and speakers, which run through an amplifier (Surround sound headphones). This is directly linked to wireless being enabled on my wireless router. In this case, placing an empty foil snack bag (like a lays chips or quaker rice snacks bag) over the small headphone amplifier box fixed it for me. I guess that the box isn't well shi
  • Technically.... (Score:5, Informative)

    by Anonymous Coward on Friday April 07, 2006 @09:55PM (#15089200)
    GSM is a TDMA (Time Division Multiple Access) system. This means a single physical channel is divided up in time for multiple people to share. A single physical channel is just a frequency range, such as 890-890.2 MHz. Each physical channel is divided up in time into what are called timeslots. Timeslots are grouped by 8's into what are called frames. Each timeslot lasts 0.577ms, and a frame is 4.615ms. When your phone is communicating with the base it is assigned a single timeslot in each frame. This means it is transmitting ON off off off off off off off ON off off... and the ON's are spaced 4.615ms apart (the frame duration). 1/4.615ms gives you 216.7Hz, which means that if (when?) it is picked up by other electronics, it is most definitely in the audio band and you will hear it. The RF transmissions die off very rapidly with distance from the antenna, which is why moving the phone a small distance away is sufficient. What else... when you hear the interference before receiving a call/SMS, this is what is happening 1) one or more base stations broadcast "hey you" to the geographic region where your phone is (your phone is always listening for this) 2) your phone contacts a specific base station requesting a channel (AUDIBLE) 3) the base station responds, assigning a channel 4) your phone goes to that channel, authenticates, etc. (AUDIBLE) 5) phone finally rings / SMS is sent
    • Re:Technically.... (Score:3, Informative)

      by Anonymous Coward
      Left off the answer to the question! Since the problem is RF emmissions from the phone, you have only a few choices: 1) move the phone a sufficient distance away 2) shield the electronics well enough that they don't pick up the RF, keeping in mind that any cables may be acting like antennas. There may be audio equipment that is shielded well enough by itself - but on the phone side, if you use GSM, you will have this problem. As others have pointed out CDMA, which transmits continuously, does not have thi
  • GSM phones make a very characteristic kind of interference. It's rhythmic, brief, and I find it interesting to listen to. The obvious solution is to move your phone away from the speakers; about 1 foot is enough for me.
  • I have a Nokia 7650 (GSM) that interferes with the speakers whenever it's updating to the towers or a SMS or call is coming in.

    I've noticed though that depending on whether or not it's just an update of location, incoming SMS, or actual call, the pattern of the inteference and the volume differs.

    I've actually learnt to ignore the location update interference - it's never very loud -, use the SMS interference to let me know without looking that I've got a message waiting, and when the speakers go,

    D

    • I have a Nokia 6010 and it interferes with my Bose noise-cancelling headphones. [bose.com] Now these are some expensive headphones ($300 SRP) and I honestly think that Mr. Bose ought to have had his people design a cord that would not pick up interference from cell phones for that price.

      I also pick up interference from other people's cell phones and blackberry devices as well. While that interference is less than the kind I get from my Nokia in my shirt pocket with the headset cable nearby (or on top), I still hear i

  • GSM seems far worse in terms of causing interference to nearby amplified speakers than CDMA. I recently switched (2 years ago) from CDMA to GSM and suddenly everything I own is spewing buzzing sounds when my phone is nearby. This happens on amplified subwoofers, PC speakers, POTS telephones, and car stereos.
  • 1) Use better speakers with better shielding
    2) Do not use mobile phone
  • This never happened to me back in the US but here in Iraq it happens all the time. I thought it was just the frequencies they use here. As far as I see it there are five solutions to this problem:

    1) Keep your phone away from your speakers
    2) Buy better shielded speakers
    3) Enclose your speakers in a faraday cage and ground the cage
    4) Enclose your phone in a faraday cage (note this may make it difficult to dial, oh yeah and it will negatively affect your signal quality too)
    5) Get a new phone

    Personnally, as s
  • by KingPrad (518495) on Saturday April 08, 2006 @04:00AM (#15089967)

    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.

  • 1. Get a BT headset.
    2. Move freakin' phone out of beepedi beep distance.
    3. Profit.
  • The solution isn't shielding, which is impractical to do effectively after the speaker system is manufactured, but capacitive bypassing. Put a 100 to 1000 pF capacitor (of appropriate voltage rating for the audio and DC voltage present) across the speaker leads as close to the speaker as possible. The capacitor bypasses the RF current of the cell phone away from the speaker, keeping the RF voltage (and its TDMA power variations occuring at an audio rate that are causing the interference) low.

    The value ran
  • by AEther141 (585834) on Saturday April 08, 2006 @07:50AM (#15090323)
    Use pro-level gear that has balanced connections on XLR or TRS jacks. Balanced cables have three conductors carrying ground, the signal, and a copy of the signal 180 degrees out of phase. Any interference affects both signal lines identically, so when they are put back in phase at the other end, any interference will be phase cancelled as it will now be 180 degrees out of phase.
  • Just move the phone away from the speakers. The transmission's power drops with the square of the distance.

    If the phone is a couple feet away on your belt and you still hear interference on the speakers, consider getting a different phone/carrier. Its also pumping that energy into your hip and other nearby sensitive areas.
  • by billcopc (196330)
    The source of this noise is the actual digital communication between your phone and the cell tower. There's nothing wrong with the phone, it's probably your speaker wiring that's picking up this signal as interference, as cheap wires have absolutely no shielding. If you don't know what kind of wiring you have, then you have cheap wiring :)

    The cellular signal is rather strong and because of the way it is modulated, it has tons of noise outside its nominal band, almost all the way down to DC. In plain engl
  • by lpq (583377) on Saturday April 08, 2006 @04:05PM (#15092052) Homepage Journal
    The Original Poster didn't say if his office speakers were wired or wireless.

    I've never experienced radiowave interference on my wired speakers, but know my house (neighborhood?) is nasty on radiowave interference. I tried purchasing some FM-speakers, but they couldn't receive a clean signal
    across my living room.

    How is your network connection? Wired or wireless? Could it be the network signal being messed with before it hits your computer and you computer just amplifies and echo's out the interference?

    I strongly doubt it's in the speaker wires. While I remember a friend of mine in college would play tricks on guys living in the next dorm room, he had a ham radio license and foot long antenna. Still he had to be less than a foot to cause the interference you are talking about -- holding the antenna parallel to the speaker wire that ran along the edge of next door room. Any farther, or disorient the antenna (not parallel to speaker
    wire) and there was no interference. He only did a few times when they were cranking music too loud -- they thought it was a problem in their setup, so they stopped cranking it so loud...:-)

    However, a cellphone, given it's small antenna and the lower power (his ham setup ~10-30W; modern cellphone: max 3W), it would be hard pressed to generate the same interference.

    I'd look to other causes than a cellphone for interference in wired speakers.

    However, for 1/8th inch connector thin-wire computer audio, most of the wire I see is shielded. RadioShack sells shielded and unshielded audio cable in lengths up to 20-30 feet. It's not that expensive: less than 20 bucks for a 20 foot extension cord last time I bought some.

    Good luck.
    -l
  • by nurb432 (527695)
    Turn the damned thing off. You dont need it anyway.
  • Get out your old physics book and turn to the chapter on resonance and Q. Built a filter. Sell the mundane filter as a new high-tech "Cell-Phone Proof Speaker". Patent something equally as mundane...maybe the color of the wires you use in builting the circuit. Profit.

    Ok, seriously...add a little series inductance to the power and audio cables, and some parallel capacitance. You want to allow audio frequencies to pass...but nothing at much higher frequencies. The parallel caps allow high frequency A/C

What the large print giveth, the small print taketh away.

Working...