How much magnetism is required to disrupt a stereo speaker?
June 20, 2012 7:29 AM   Subscribe

Um, uh... "hypothetical" physics question involving magnetism or electromagnetism to disrupt a stereo speaker... you might be a little entertained. Or not.

A simple stereo speaker, maybe ten cubic inches, is on one side of a typical (2x4 studs and plates/drywall) wall. Directly opposite it, on the other side of the wall, might be situated a large magnet (hung there permanently) or (for a few moments) even a simple homemade (large bolt or screw wrapped in wire that runs to a battery or, in the case of extreme bravery and some good research, a wall outlet -- yes, I know you'll advise against the latter) electromagnet. How big of a magnet or electromagnet would be required to disrupt permanently the magnets in the stereo speaker (which causes the wall to vibrate like a massive speaker bass chamber and is extremely annoying) ?

Disruptive non-magnetic ideas are welcome as well.

Um, uh... thanks. ;-)
posted by Shane to Science & Nature (14 answers total)

This post was deleted for the following reason: It wasn't really initially clear how not-so-hypothetically not-cool the idea here was, but to be clear this is pretty much not an okay sort of thing to ask for help with from Ask Metafilter. -- cortex

I'm curious to read results in the magnetic field of research in this area. However, I have something to contribute from my own research in the non-magnetic area.


1. Procure a second stereo speaker of similar size and power.

2. Place the speaker so it faces the shared wall, touching the wall.

3. Retrieve two large soup ladles from the kitchen. Ascertain whether there is any sort of visible plumbing system shared by both apartments - a radiator or the like. If there is, set the ladles by the closest exposed area of this system. If not: simply leave the ladles by a piece of furniture also adjacent to the shared wall.

4. Wait for such event that the speaker on the other side of the wall is utilized. When it is, turn on the stereo connected to the aforementioned stereo speaker in one's own apartment and load a copy of the soundtrack to O Brother, Where Art Thou?. Cue up track 16 (the full-band version of "Man of Constant Sorrow").

5. When there is a lull in the music on the other side of the wall, start the stereo and crank the volume up to full. While the music is playing, use the ladles as percussive instruments to drum on the plumbing or furniture in time to the music. Vigorous stomping and dancing can also be utilized. When the track ends, repeat. Just the once.


Following the experiment in this manner often leads to greatly diminished noise output from the speaker on the other side of the wall. It may also lead to neighbors in other adjacent apartments randomly shouting "Yeeee-hawwww!"
posted by EmpressCallipygos at 7:51 AM on June 20, 2012 [3 favorites]

One last point:

Further research in this area is exploring the effect of the specific type of music utilized in such an experiment, and most studies suggest that for this experiment to be effective one must select a piece of music which is markedly different from the music emenating from the speaker on the opposite wall.

The aforementioned use of "Man of Constant Sorrow" is effective for most purposes; the first time the experiment was conducted, "Man of Constant Sorrow" was effective in terminating an unidentified piece of French techno music. It has been theorized that if the music from the other speaker is too similar to "Man of Constant Sorrow," then "The Chicken Dance" could be an effective substitute. However, this theory has not as of yet been tested by our labs (even though we secretly kind of want to).
posted by EmpressCallipygos at 7:57 AM on June 20, 2012

I think I would look into "re-purposing" an old microwave oven rather than procuring industrial strength magnets. I can imagine just taking the door off, (yet fooling the microwave into thinking the door is closed) , hanging the doorless microwave on the wall at the approximate speaker height, (having checked no electrical wires are in the way), and then giving the wall/speaker an experimental "defrost, reheat, or full-on nuke" may or may not be effective.

Caveat microwave-or - Fun in theory, possibly attempted arson in practice.
posted by guy72277 at 8:07 AM on June 20, 2012

Great suggestion, Empress! I had considered something similar, but without such excellent and detailed exploration of the variables involved (comparative effectiveness of "Man of Constant Sorrow" vs. "Chicken Dance" emanating from what we shall call Speaker B and the nature of their effectiveness vis-à-vis the genre of noise from Speaker A; I especially like the viscosity and texture of "Man of Constant Sorrow" compared to, well... anything else I can think of, except maybe some tracks by Laibach, although Don Ho, whose rendition of "Tiny Bubbles" is IMHO charming when heard once or twice, should not be discounted when played several dozen times in a row.)

What I forgot to mention is that, for most of the time, the hypothetical other-side-of-the-wall-from-the-speaker can, in this experiment, only play music of a calm variety at reasonable decibels, due to it being a business address.


We'll remember you as a last resort, though, especially as our hypothetical ears have heard the bass line to Aerosmith's "Walk This Way" well over 100 times thus far (and hypothetically 4X that much by the ears of longer-term employees).
posted by Shane at 8:13 AM on June 20, 2012

If it doesn't work to build electromagnets with exposed wiring, form a jug band, or irradiate your apartment, you might also try asking them politely to turn it down.
posted by echo target at 8:14 AM on June 20, 2012 [2 favorites]

Ah, I should mention that our experiments were conducted in residences.

The fact that the location of this experiment incorporates a business address suggests an initial step of requesting that the opposing speaker (as your speaker is B, their speaker would be A) to be pulled about six inches away from the wall. If Speaker A is able to be thus repositioned, the experiment can be safely abandoned.

If this request is met with a rude refusal - but only if that refusal is rude - I would suggest, instead of Don Ho, to use "Girl From Ipanema" in any derivation. This, however, is a last resort.
posted by EmpressCallipygos at 8:18 AM on June 20, 2012

Thanks, guy72277! Guy is my last name, BTW. Excellent idea, although prior research into the effects of microwaves on drywall would be necessary.

Empress, hypothetically that (6" away from wall) suggestion has been made and offers have been made TO DO IT FOR THEM, to no avail.

echo target, this has been tried repeatedly, and they're (hypothetically) too busy, can't figure out the simple task of rerouting speaker wire that is run above ceiling tile, and don't want to turn down the music because they're a popular fast-food franchise and will receive bad marks from their district manager if the music is too quiet. The offer of repositioning the speaker my(hyopothetic)self has been made as well. Hypothetically, the side of the wall opposite them treats urgent care medical patients who often ask if there's a party going on next door and often are sick and annoyed and should be subjected to better decorum.

Hypothetically, ENOUGH IS ENOUGH.
posted by Shane at 8:21 AM on June 20, 2012

Perhaps the request to relocate speaker A should be escalated to the district manager, then?

The fact that there would be civilians with diminished health present while conducting your own experience troubles me; as mentioned in my previous note, "Girl From Ipanema" would be potent, but should only be used as a last resort, as Ipanemum is highly caustic in large quantities, and will be damaging enough to the primary research team.


Okay, dropping the cute speak for a minute. If you and this fast food place are both leasing your businesses, I would involve the building's owner. I'm not sure what the legal guidelines for noise polution in terms of businesses would be, but if you get the owner to just stand there in your waiting room and listen so he gets what the issue is, he could be enlisted to be on your side, and that could be a potent ally.
posted by EmpressCallipygos at 8:28 AM on June 20, 2012

And they want to pay minimal royalties for the music they play w/o much billing hassles so they play the same eight (EIGHT!) old songs over and over all day long. &%!$ing hypothetically, of course.
posted by Shane at 8:28 AM on June 20, 2012

Thanks. Noted, Empress.
posted by Shane at 8:29 AM on June 20, 2012

I have another idea that is also not entirely safe, yet.....

Procure an arc welder.

I have had experience in the past with an electric (aircon) switch that when held between the on/off position (which presumably creates a spark) disrupted a DJ's sound system in a nightclub (amplified buzzing). Now I'm imagining that a good way of creating such sparks on a more industrial scale would be an arc welder, or perhaps a tesla coil.

Instead of just breaking the speaker (microwave method) which would no doubt be efficiently replaced by a more powerful model, the sound system's buzzing may cause such irritation to the customers that it will be replaced in its entirety and the problem of a wall mounted speaker may be gone for good.

Please note that Tesla coils can be made to buzz with specific melodies, so playing Looped Dixie through your neighbor's speakers may be possible (see youtube vids)...
posted by guy72277 at 8:36 AM on June 20, 2012

Jesus, this is a business doing this? All day? Aren't there noise ordinances in your hypothetical area? Get it on the local news, involve the cops, sue them, make it more painful to the manager or district manager or corporate headquarters. Sabotage will only get someone in trouble.
posted by Etrigan at 8:53 AM on June 20, 2012

It's a business. You wouldn't take the Subway to get to it, but that's where you might end up. Yes, eight songs over and over all day, and you can feel the wall throb with the bass. Thanks for all the ideas. Tesla coils are great but scare me a little, lol. The news wouldn't be interested. The franchise owners might be afraid of their DM, and I hadn't thought of that. I considered threats of a newspaper ad, but the hassles and expense make it a hollow threat. The urgent care is in a part of town that's considered kind of hillbilly-poor-ghetto, so no one cares much except the patients. The cops wouldn't care, although almost all cops treat medical personnel with respect. The hospital system that owns the U.C. treats us like the boondocks satellite. I'll offer one more hypothetical time to come in and help the owner relocate the speaker off the wall, and if that doesn't work I just want the hypothetical noise to stop before I lose my hypothetical sanity. And Mr Wizard taught me that science is my friend.
posted by Shane at 9:06 AM on June 20, 2012

I do know a chap who claims to have ripped the magnetron out of an old microwave, mounted it on a broom handle and used it to destroy the speakers of his upstairs neighbour. It's a completely plausible story coming from this guy, whose hobbies include building capacitor banks and spark generators then laughing maniacally as ludicrous voltages spark across his garden shed.

Of course, it should be noted that this is rather dangerous. In addition to cooking any people that you hit with your expanding, wall-penetrating beam of invisible energy, the microwaves in an oven have a wavelength in the centimetre range, meaning that the energy will be efficiently absorbed by any bits of metal that are a few cm long. So to pick a few examples at random, any phones, laptops and pacemakers in your line of fire could be seriously damaged, and random bits of metal might get hot enough to injure people and/or start fires.

Now, a home microwave oven isn't that powerful, and the inverse square law will mean that the nastiest effects will be confined to a pretty short range. I guess what I'm saying is, unless you happen to be an electrical engineer (or have a tame one nearby) who can do these calculations properly, proceed with extreme caution.

On a slightly more practical (although still illegal) note, it's not terribly hard to interfere with unshielded speaker cables. Get a power source (let's say 12V and a couple of amps... a laptop power supply would do) and attach a rough file or rasp to one terminal, and make a small bush of copper wire to attach to the other. Brush the rasp with the wire bush. You'll be very rapidly starting and stopping the current through your circuit, which will create a lot of EM noise. If nearby speakers are unshielded, they should pick it up as buzzing, popping and general unpleasantness. Note that you can't aim this, and that it will also interfere with other unshielded electronics in the area, particularly stuff like wireless intercoms, phones, etc.

Some important notes:
(a) this is totally illegal - flooding chunks of the radio spectrum with noise is very much not allowed, especially if it's a deliberate attempt to interfere with other equipment
(b) as I've described it, you're intermittently short-circuiting your power supply. Carried on for more than a few seconds, this can damage the power supply and/or cause it to be come hot and therefore a fire hazard. It's much better to have some sort of electrical load in the circuit, but you'd have to get better advice from an actual electronics guy.
(c) When faffing with electrical circuits, excercise proper caution. If you don't know what proper caution is in this context, don't faff with electronics until you've found a teacher :).
posted by metaBugs at 9:08 AM on June 20, 2012

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