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So I have a klipsch swI sub connected directly to a dvd player via RCA. For some reason when the volume on the sub is all the way down I can hear (what I can only assume to be) FM radio. Its rap music (of which none of my stereos in the entire house have stations set for) i even took the DVD out of the player, disconnected it from the TV and receiver. So now what we have is a sub connected to power (via power outlet on a breaker nothing but 2 snake lights are connected to) in room A with signal from RCA to a DVD player connected to NOTHING in room B playing rap music. ANy ideas?
 

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I've got an identical problem, using a 50' run of monoprice XLR to RCA cable to my sub. Living about 3 blocks from an AM Spanish speaking station, I can fairly well make out the talk station voices during quiet moments. Happens during the colder months (low humidity) when the sub is turned on, but regardless if the receiver is on or not.


You'd think with these cables being shielded, there wouldn't be a problem?
 

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Some unshielded cables will pick up RF signals. You can try a shielded cable (RG6 quad shield).


Very rarely, some amplifier sections on subwoofers will pick up RF. One guy placed aluminum foil around his subwoofer to solve his RF problem initially. In essence, he jury rigged a Faraday cage.
 

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Quote:
Originally Posted by wwinkler /forum/post/19612828


Some unshielded cables will pick up RF signals. You can try a shielded cable (RG6 quad shield).


Very rarely, some amplifier sections on subwoofers will pick up RF. One guy placed aluminum foil around his subwoofer to solve his RF problem initially. In essence, he jury rigged a Faraday cage.

So what you're saying is that he put a tin foil hat on his sub?
 

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The steps.

When he first hears the AM station, disconnect the cable from the receiver to the subwoofer. If that solves the problem, get a new (shielded) cable.

If it does not, try the aluminum foil 'cap' as a temporary solution. If it solves the problem, try something more permanent. I have no idea what a permanent solution would be.
 

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This was a common problem back in my days as a remote broadcast engineer for a radio station. The solution when shielded cables were not enough was the addition of an induction coil.
 

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Quote:
Originally Posted by Rob Morse /forum/post/19613754


This was a common problem back in my days as a remote broadcast engineer for a radio station. The solution when shielded cables were not enough was the addition of an induction coil.

Or a full steel conduit that the cable runs through, should shield the better part of the cable to eliminate that nuisance.


I used to live right next to an interstate hwy, when I first hooked up my system in there, CB radios from the truckers with high gain antennas would drive by and the chatter could almost blow my speakers. I ran some electrical conduit to shield the speaker wires - problem solved...
 

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Quote:
Originally Posted by wwinkler /forum/post/19613690


The steps.

When he first hears the AM station, disconnect the cable from the receiver to the subwoofer. If that solves the problem, get a new (shielded) cable.

If it does not, try the aluminum foil 'cap' as a temporary solution.

Disconnected the cable - no noise, so must be in the cable.

Quote:
Originally Posted by Warpdrv /forum/post/19614152


Or a full steel conduit that the cable runs through, should shield the better part of the cable to eliminate that nuisance.


I used to live right next to an interstate hwy, when I first hooked up my system in there, CB radios from the truckers with high gain antennas would drive by and the chatter could almost blow my speakers. I ran some electrical conduit to shield the speaker wires - problem solved...

Thanks, for the suggestion. Wish there was a simpler solution than running conduit, I'm not much of a handy man. I may have to re-arrange the room to put the sub in the front where it probably should go anyway.
 

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Quote:
Originally Posted by sbdman /forum/post/19615569


Disconnected the cable - no noise, so must be in the cable.




Thanks, for the suggestion. Wish there was a simpler solution than running conduit, I'm not much of a handy man. I may have to re-arrange the room to put the sub in the front where it probably should go anyway.


I would honestly take wwinkler & dachness's suggestion on this one...


Let me be clear, I never installed any of this conduit anywhere, I just ran the wires through it and layed it on the floor....
It was behind the entertainment console on along the wall so no-one saw it, so I didn't care what it looked like..... it was just a simple inexpensive solution, as I had the conduit laying around....
 

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I was using this one from Monoprice to try not to add extra adapters when going from XLR to RCA . It says something about shielding, but might be a typo.


I'll give this a try as well. Would be nice not to hear those whispering voices all the time!
 

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Quote:
Originally Posted by sbdman /forum/post/19616178


I was using this one from Monoprice to try not to add extra adapters when going from XLR to RCA . It says something about shielding, but might be a typo.


I'll give this a try as well. Would be nice not to hear those whispering voices all the time!

Upping my meds works great for voices.
 

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Quote:
Originally Posted by dachness /forum/post/19615680


Try a monoprice RG6 cable first, as suggested above: http://www.monoprice.com/products/pr...seq=1&format=2


Daniel

Well, I tried your suggestion, and no change from the previous cable I was using. Other than laying down conduit like Warpdrv suggested, I'll either have to turn off the sub at lower volumes, or just put up with the muffled chatter until spring.



Speedskater - looks like great theory presentations, but falling short of taking a graduate coarse in EMI and designing some black box, would be nice to buy some off the shelf product (that would work)...


sputter1 - any meds you can spare, I'd be glad to share!



audiogod69 - sorry for hijacking your post!
 

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Wouldn't hurt to chat with monoprice and see what they have to say about it.


So what setup did you try? XLR should have the best shielding so if you maximized that and used the least RCA cable it may help.
 

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I started with monoprice's XLR to RCA cable from DSP1124 to sub's RCA (no XLR available) input. Tried the suggested high-quality RCA to RCA RG6 adding a 1/2" mono plug to RCA adapter - the gold plated one. The cable was advertised as double shielded, didn't see one that was quad shielded, and doubt it would make a difference. I think Warpdrv's suggestion of conduit (think Faraday shield) would work, but sounds a bit too cumbersome.
 

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Over time, several individuals have indicated situations where their receivers and, in one case, a subwoofer amp picked up RF are certain frequencies.


After one guy's shielded cable did not work, he jury rigged a Faraday cage with aluminum foil that did work. If it works, then you know where your problem occurs and can work on a more permanent solution.
 

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Ferrite chokes


Radio Shack #273-105 or maybe #273-104


Try one on the interconnect very near the sub, then try another on the power cord near the sub.
 

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Quote:
Originally Posted by Speedskater /forum/post/19673582

Ferrite chokes


Radio Shack #273-105 or maybe #273-104


Try one on the interconnect very near the sub, then try another on the power cord near the sub.

Just wanted to report back in. I tried one of the 273-105's next to the sub with no results, but then found the same item on Amazon through Parts-Express for almost 1/3 the price, so ordered 3 more, spaced them equally across the 50' RCA cable, and voilÃ* - no more radio interference!


Thanks so much for what seemed like a snake oil solution, but really works, Speedskater! My sub is now silent when it should be, peace is restored.
 

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Awesome! I'm glad you found a solution!
 
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