Needed: speakers that are immune to GSM buzz

April 10, 2008 9:56 PM

Got a lead on some decent-sounding, not-outrageously-pricey speakers that are shielded from GSM buzz?

I have my speakers plugged into my Mac, and I also plug my iPhone into it. I searched AskMe, and some people said "just move your phone away from your speakers". That isn't much of an option for me, given the fact that I regularly need to sync my iPhone and my Mac, and it's also very convenient to have my phone next to my laptop instead of on the other side of the room. Others suggested getting speakers with shielded wires. Can you recommend something that would work? I don't know where to even begin. I'm completely ignorant about speakers, and I don't really want to learn anything. I just want to buy something that won't make that irritating buzz, and will reproduce the music I listen to somewhat decently.

posted by evariste to shopping (10 answers total)

I notice no interference on a set of Harman Kardon Soundsticks II. With a little diligence, I managed to get mine on eBay for under $50.
posted by bunji at 10:23 PM on April 10, 2008

Oh no, my mistake -- my husband says he has had those speakers pick up some kind of interference, although I've not heard it myself. Sorry for the false lead!
posted by bunji at 10:44 PM on April 10, 2008

I'm hoping someone knowledgeable about speakers will comment in this thread. I've always been of the understanding that speakers are required to accept outside interference. (Yes, I know there are probably high end speakers out there that include much thicker shielding, but the level of shielding required to protect speakers from ANY potential external interference would be prohibitive. )
posted by jmnugent at 11:02 PM on April 10, 2008

Others suggested getting speakers with shielded wires.

It depends on how the path of interference.

Does the buzz vary with volume? (Which is what I assume.) If so then the problem isn't with your speakers or in the cables that connect them; it's in your computer. Your only option is to physically separate/shield your iPhone and the computer.

If the buzz doesn't go up and down with volume control, then the interference is probably being picked up in by the cables and pulses are transmitted to the coil of your loudspeaker along with the music signal. A shielded cable will help.

Based on the number of complaints I hear, the iPhone seems to generate an unusual amount of interference as compared to other GSM phones. I wonder if the antenna design in the iPhone is somehow deficient and the transmitter is forced to operate at a higher than normal power level?
posted by three blind mice at 1:13 AM on April 11, 2008

I don't get GSM interference on my Klipsch Promedia 2.1 speakers. The same cell phone produces really loud interference on a pair of cheap Altec speakers I also have.
posted by good in a vacuum at 1:20 AM on April 11, 2008

Seconding Harmon Kardon Soundsticks. I used to have cell service through Cingular/AT&T and my old Altec Lansing speakers broadcast the dreaded GSM buzz at least once an hour. I found some Soundsticks on eBay for about $70 a couple of years ago, and after plugging them in, never heard the GSM buzz again.

I recently switched to a non-GSM wireless service, but I had the combination of Cingular/Soundsticks for nearly two years and never ever heard a buzz — not even once.
posted by tomwheeler at 6:32 AM on April 11, 2008

IANAElectrical Engineer but I hang out with them :)

A wire and an antenna are only different in name. The only sure-fire way to guarantee that you won't get interference is to use balanced audio or digital audio, neither of which is particularly cheap.

Sound cards with balanced outputs are stupidly expensive (for no good reason) and you're also limited to active speakers with balanced inputs, also not a cheap proposition. Massive overkill in other words.

Digital audio may or may not be an option. If your mac has SPDIF output (which I don't think most do) you could get speakers like these and hook 'em up that way. Slightly less massive overkill.

I didn't know such things existed but there are also apparently USB Speakers which will eliminate the exterior analog signal path just as well as the SPDIF option. I'd investigate this if I were you.
posted by Skorgu at 8:11 AM on April 11, 2008

Thanks, everyone!

three blind mice: I'm guessing you hear more complaints from iPhone users because people who buy Apple products are more likely to whine about them (including me!).
posted by evariste at 7:16 PM on April 11, 2008

Audio signals from a source (say a computer) go into an amplifier. The amplifier drives speakers. Sometimes the amplifier is built into the speakers, as with PC speakers, or sometimes the amplifier is in a receiver or bookshelf stereo. Most noise gets in the signal coming out of the source (aka PC), before it gets amplified, and there are three solutions to this. Amplify the signal before it gets close to the noise source, shield the signal from the noise source, or remove the noise source.

In this way, PC speakers are particularly susceptible to noise. The amplifier is as far from the signal source as possible, giving lots of space to pick up noise, the cable carrying the signal is cheap and poorly shielded, and the noise source is right on your desk beside the speakers (more importantly, beside the low level signal wire and the amplifier).

For those reasons, and because PC audio solutions are invariably poor economy, even if they do sometimes produce acceptable acoustics (a point which is debatable in itself), I would do the following. Get an audio amplifier (a receiver or bookshelf stereo perhaps? Any audio amplifier that meets your size and style requirements will do, but some are better than others), and a pair of small (or, you know, 300Tis) passive speakers. Then get well shielded interconnect wires for the connection from computer to amplifier, and be careful to route those wires as far from noise sources as possible. This is your best bet for low cost high quality audio, and it should be your best bet for noise immunity too. This solution is made much easier if you have an LCD monitor, because unlike CRTs, an LCD isn't bothered by powerful magnets (aka good speakers) getting too close.

That said, I don't have a cell phone, so my experience with this particular issue is limited. It is remotely possible that cell phone noise wreaks havoc on all stereo equipment, but my impression has been that it is a PC speaker issue.
posted by Chuckles at 7:29 PM on April 11, 2008 [1 favorite]

I never did wind up buying any nice shielded speakers. However, I've replaced my original iPhone with an iPhone 3G, and it doesn't have the problem!
posted by evariste at 3:50 PM on July 24, 2008