External speakers picking up someone else's music

Discussion in 'Macintosh Computers' started by Ambrose Chapel, Dec 20, 2003.

  1. Ambrose Chapel macrumors 65816

    Ambrose Chapel

    Joined:
    Jul 24, 2002
    Location:
    Massachusetts
    #1
    I have some decent harman/kardon speakers plugged into my TiBook's headphone jack. They have their own power brick that's plugged into my surge protector.

    Very often, the speakers will play music from who knows where at low volume. The volume doesn't change if I adjust it on the speakers. It's picking it up from the power I suppose, though if I unplug them from the TiBook but leave them powered and turned on they don't pick up any phantom music.

    Is there some sort of device I can attach to them to block this music? It gets drowned out if I'm playing louder-style music, but it many cases I can still hear it over what I am playing and it's making me nuts.

    Any help would be appreciated
     
  2. question fear macrumors 68020

    question fear

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    The "Garden" state
    #2
    i cant help with your problem but i have had a very similar one with my coby surround sound system...i had some of the cables crossed wrong and suddenly was getting radio disney AM on one speaker (i think it was the closest AM tower).
    so actually, iwould be very interested ina n explanation for this too.
    -carly
     
  3. WinterMute Moderator emeritus

    WinterMute

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    #3
    The main problem is that you are using unbalance cables for the audio from the mac to the speakers, 2 core cables use a common earth and negative lead, and are suseptible to RF (radio frequency) interference. Balanced cable uses 3 cores, a +, - and a separate earth/screen, it is much better at rejecting RF.

    You don't have a choice in the cabling unfortunately, and the remedy is to get the speaker amp to earth the audio signals through the Mac, not seperately, you have an earth issue when you connect the Mac and the speakers to a common earth, (your mains iin this case), the remedy in the studio would be to drop the earth from the signal cables connecting the speakers to the Mac, this may be impractical in your situation, but it explains why the problem vanishes when you disconnect the unit.

    You might want to check the earthing in your home, as this is where the problem stems from, check the connections in your multi-power board, and in the plugs, then see if you can find the main earth to the building and see if it's OK.

    Dropping the mains earth off one or other unit would also work, but is very dangerous, as it leaves you open to shocks.
     
  4. crazzyeddie macrumors 68030

    crazzyeddie

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    Florida, USA
    #4
    In the above post, if anyone is confused, what he refers to as "earth" is commonly known as grounding.
     
  5. rjrufo macrumors regular

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    Boston
    #5
    The British have a language all their own, don't they. :D
     
  6. Counterfit macrumors G3

    Counterfit

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    #6
    That was actually the only thing I understood :confused:
     
  7. OutThere macrumors 603

    OutThere

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    NYC
    #7
    That happened a while ago with a guitar amp, it was playing radio without having anything plugged into it. It was pretty cool. It would really suck to have it in your fancy computer speakers though. This was just a crappy practice amp that some people were using in the basement.
     
  8. WinterMute Moderator emeritus

    WinterMute

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    #8
    Yes, it's the one we loaned to you lot, and now it's all busted up and bent out of shape:D :D ;)

    Thanks crazzyeddie for the assist.
     
  9. manitoubalck macrumors 6502a

    manitoubalck

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    Location:
    Adelaide, Australia
    #9
    I have a similar yet differnt issuem which isn't really an issue. If I swith to CD imput on my 20 year old NAD amp and crank the volume I can start to softly hear the music comming in over the Tape imput (computer.) Not sure why it happens but only occurs at extremly high volumes, hence isn't really an issue.
     
  10. WinterMute Moderator emeritus

    WinterMute

    Joined:
    Jan 19, 2003
    Location:
    London, England
    #10
    This is known as electronic cross-over or sometimes bleed-through, high levels of signal through older systems tend to wander about a bit as the sheilding on the older systems was either a bit lacking to start with or again has been compromised in the earthing (grounding!) due to oxidation in the contacts amongst other things.

    Earth is a very important part of any audio system, get it wrong and all kinds of weird sh*t happens.

    It also plays a major role in the sound of a system, as does the power supply, but that's a horse of a different colour.
     
  11. Ambrose Chapel thread starter macrumors 65816

    Ambrose Chapel

    Joined:
    Jul 24, 2002
    Location:
    Massachusetts
    #11
    thx for the tips; unfortunately i'm in an apt building so i can't really do anything about the wiring..

    maybe if i got speakers that were FW powered or somrthing? fortunately these were freebies that had been laying around my parents' house.
     
  12. ~Shard~ macrumors P6

    ~Shard~

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    #12
    Um, actually the British have ENGLISH, and created, developed and refined it over many many centuries before "passing it along" to us here in N. America - we're the ones who have screwed it all up. :cool:
     
  13. Macpoops macrumors 6502

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    PA
    #13
    Screw it we made sense of it. Bollocks? The Dogs bollocks? what the hell is that?
     
  14. rjrufo macrumors regular

    Joined:
    Sep 18, 2002
    Location:
    Boston
    #14
    Or what about a flat? Isn't that an appartment or something? But then again, why do we call it an appartment when they're all together?

    There are several others that I can't think of at the moment because I've had too much eggnog.

    Anyway, I hope everyone had - or is having - a great Christmas.
     
  15. Ambrose Chapel thread starter macrumors 65816

    Ambrose Chapel

    Joined:
    Jul 24, 2002
    Location:
    Massachusetts
    #15
    so here is my solution:

    i bought a really long stereo cable and hooked my Ti up to my receiver. i have a cable across the floor, but it works and i have much better sound than i ever did from the tabletop harman/kardons
     
  16. WinterMute Moderator emeritus

    WinterMute

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    #16
    Yeah, you made sense of it alright:rolleyes:

    The reason English (The Queen's Version) is so difficult is to oppress the populations of the colonies even further when they have to learn it:D

    English is the worst language in the world to learn as a foreign language, QE or American.

    At least I get some Idea of what our Atlantic cousins are talking about.

    Obviously you don't know what the dogs bollocks is about, it decribes being the absolute best, something you'd know precious little about;) ;) :p

    Ambrose Chapel:

    You'll always get a better sound out of a proper set of hifi speakers, cables are a nuisance, but good audio is worth it.
     
  17. Macpoops macrumors 6502

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    PA
    #17
    So wait? Bollocks is bad? and the Dogs Bollocks is the best? One thing i do love that happens to be english, Rugby. Now thats a mans game. More manly then anything we have here in the states, our Football is a close second but hell we wear lots pads and take too many breaks.
     
  18. johnnowak macrumors 6502

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    Jul 24, 2003
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    New York, New York
    #18
    Thank god for the English!

    I mean TVR, Caterham, Westfield, Aston, Ariel, Morgan, come on! ;-)
     
  19. Counterfit macrumors G3

    Counterfit

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    #19
    I think I should work some equations out to find out who hits harder...

    johnnowak: Don't forget McLaren! Or Jaguar, I mean really, who names crap after a cat? :rolleyes:
     
  20. Macpoops macrumors 6502

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    PA
    #20
    Ehh i think football might have slightly harder collisions just because of the objective. In my experiance with rugby your not just trying to run through a man most of the time your turning your body or going to ground when you go into contact. Even on defense your trying to hold the man up most of the time. In football you always trying to get the man down on D or even on O in some times.
     
  21. Counterfit macrumors G3

    Counterfit

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    #21
    But then there's Larry Allen :D I would hate to get hit by him.
     
  22. ~Shard~ macrumors P6

    ~Shard~

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    #22
    Okay, so what was the subject of this thread? ;)
     
  23. Wes macrumors 68020

    Wes

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    Jun 22, 2001
    Location:
    London
    #23
    The subject: Hm... Bri... Engla.... oh yeah, some speakers having grounding issues.
     
  24. ~Shard~ macrumors P6

    ~Shard~

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    #24
    Right, thought so. Alright, thanks, carry on then! ;) :cool:
     

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