Extreme Newbie, having hummm in Subwoofer

Discussion in 'Archived Threads 2001-2004' started by MidgeD, Feb 16, 2002.

  1. MidgeD

    MidgeD Auditioning

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    Hello all, glad I came across this forum.

    I just bought a system and hooked it all up and I'm getting just a loud hum from the subwoofer. The other speakers are working fine.

    I have the following equipment.

    Sat Receiver

    DVD/VCR Combo

    A/V Reciever

    Big Screen

    I don't know what other info you need me to post or if that helped or not.

    But any info on why you think this is humming I'd appreciate it.

    It sounds like it's not grounded somehow.

    TIA
     
  2. CRyan

    CRyan Screenwriter

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    You already nailed it. It sounds very much like a ground loop problem. Try using a cheater plug for the Subwoofer (assuming it is a powered sub). A cheater plug, in case you do not know, will take a grounded plug and turn it into a simple two prong plug. These can be found at any local hardware store and even wal-mart.

    If that does not work, try using it for your receiver. More times than not, it is the cause of the satellite receiver. The cheater plug is not a real solution. You can purchase a line conditioner for around $150 that should solve this problem while helping other things like video quality as well.

    Anyway, try using the cheater plug in your system and see if that reloves the problem. Report back with what you find.

    C. Ryan
     
  3. Vic_T

    Vic_T Stunt Coordinator

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    Also, the cable going from the amp to the sub woofer should be a sheilded cable. If you used just a standard cable with a phono jack on it you could be picking up a hum. A cable labled as a sub-woofer cable will be sheilded.
     
  4. MidgeD

    MidgeD Auditioning

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    Thank you both. I will try both of these.
    It is a powered sub. It came with a black RCA plug? Looks just like the Red & White audio plugs.
    CRyan, so if I go to Rat Shack or Wally World just ask them for a Cheater Plug? and they'll know what I'm talking about? I really thought it was from the Sat Receiver to begin with.
    Thanks to you both again [​IMG]
     
  5. CRyan

    CRyan Screenwriter

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    [​IMG]
    This is what you are looking for. Should be less than a $1.
    The cable could be a source of trouble as well. You can make very good Sub cables yourself using quad shielded coax and connectors available at Radio Shack. I can explain this to you if you need. It is relatively cheap and then you get the exact length you need.
    C. Ryan
     
  6. Vince Maskeeper

    Vince Maskeeper Producer

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  7. CRyan

    CRyan Screenwriter

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    Vince, mine above is much prettier and it only costs .59 at home depot. [​IMG]
    C. Ryan
     
  8. MidgeD

    MidgeD Auditioning

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    Well shoot, that didn't work [​IMG]
    Maybe it's just not wired correctly?
    I only have the 1 cord. Please excuse me but I know I won't word these correctly.
    1 cord into Big Screen TV which is the coaxial (satelite in)
    Now maybe this is the reason for the hum? Maybe I have to run the wires differently? From the TV more?
    I just can't figure out why the other speakers are working properly and the subwoofer has no sound except the loud hum.
    When they were out here putting in the new DirecWay they looked at it and couldn't get it to work. But my DirecWay still doesn't work and I knew more then they did about computers and such. So I don't know what to think now.
    Maybe it's just a bad subwoofer? But I'm thinking it should be wired different.
    When you touch the RCA plug on the back of the subwoofer as it's humming you can get it to actually have sound from the TV/DVD etc source. That's holding it right at the base as it's in the back of the subwoofer and moving it around. So maybe there is a definite grounding problem there afterall.
    Dunno, look forward to trying something else.
    Thanks again
     
  9. Vince Maskeeper

    Vince Maskeeper Producer

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    Well, I would start experimenting and seeing what is happening.

    Disconnect the cable between the receiver and the sub- does the hum stop? Disconnect the cable from the receiver, and leave it connected to the sub, does the hum stop? If you disconnect the cable from the receiver and the hum stops, try touching the tip of the cable connected to the sub- do you get a buzz when you touch it?

    If the buzz goes away when you disconnect the sub from the receiver- then try leaving the sub connected to the receiver and disconnecting other things. Try unscrewing the coax from your satellite box. Try disconnecting everything until you have only the receiver and the sub- with no other sources connected- does the hum stop? Is there any receiver connection that makes the hum stop/start? Disconnect devices one at a time, see if you can find one that makes it stop.

    Are you getting any audio from the sub when you playback material in addition to hum- or just hum and no audio? Are you sure it's connected to the correct output on the receiver and the right input on the sub?

    I would seriously suggest trying another cable- if even the audio cable from your DVD player or something- any cable you have handy that you could take a shot with.

    Does it buzz when the receiver is turned off? Did the ground lift plug change the volume of the buzz or the tone of the buzz at all? Did you try the ground lift on the sub's plug? Did you try the ground lift on the receiver's plug? Did you try a ground lift on both plugs?

    -V
     
  10. CRyan

    CRyan Screenwriter

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    Vince covered all the bases. Without knowing what all you have hooked up and where, it is difficult to know where to start.

    Do you have the satellite audio going into your receiver? Well the question could get endless. Basically, you are going to have to back to the good old scientific method. It may take a while but you will get it figured out. First try taking the satelite receiver out of the equation. Then just go from there disconecting evertyhing till the hum stops. It could be combination of things in your setup.

    Do you have to RCA style plugs going into the sub? If so try just using the left (white) one.

    Have you tried plugging the sub into an outlet that is on a completely different breaker?

    Anyway, you have several things to check. If NONE of these ideas work, then maybe the connector inside the sub has a bad solder. It happens.

    C. Ryan
     
  11. MidgeD

    MidgeD Auditioning

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    Disconnect the cable between the receiver and the sub- does the hum stop? Disconnect the cable from the receiver, and leave it connected to the sub, does the hum stop? If you disconnect the cable from the receiver and the hum stops, try touching the tip of the cable connected to the sub- do you get a buzz when you touch it?
    A=Disconnected the plug going just into the p-sub. Hum stopped. Disconnected plug from receiver hum continued. So it's basically in the sub I'd think? [​IMG]
    If the buzz goes away when you disconnect the sub from the receiver- then try leaving the sub connected to the receiver and disconnecting other things.
    A=I left plug in sub and then proceeded to pull one by one each plug and nothing stopped the hum.
    Try unscrewing the coax from your satellite box. Try disconnecting everything until you have only the receiver and the sub- with no other sources connected- does the hum stop?
    A=No, hum still is there.
    Is there any receiver connection that makes the hum stop/start? Disconnect devices one at a time, see if you can find one that makes it stop. Are you getting any audio from the sub when you playback material in addition to hum- or just hum and no audio? Are you sure it's connected to the correct output on the receiver and the right input on the sub?
    A=No, not getting any audio from the sub whatsoever. Yes, I'm sure it's in the right input/output. [​IMG]
    I would seriously suggest trying another cable- if even the audio cable from your DVD player or something- any cable you have handy that you could take a shot with.
    A=Tried 3 different cables. From the one that came with it to audio RCA plugs to a monster $60 cable and all of them didn't change it.
    Does it buzz when the receiver is turned off?
    A=Yes, it buzzes when the receiver is off. I even tried plugging it into different power sources around the house and it still buzzes.
    Did the ground lift plug change the volume of the buzz or the tone of the buzz at all?
    A=No
    Did you try the ground lift on the sub's plug?
    A=Yes
    Did you try the ground lift on the receiver's plug?
    A=No, I have everything else accept the sub plugged into a Power Strip.
    Did you try a ground lift on both plugs?
    A=No just the sub.
    ====================================
    CRyan
    Do you have the satellite audio going into your receiver?
    A=Yes
    Well the question could get endless. Basically, you are going to have to back to the good old scientific method. It may take a while but you will get it figured out. First try taking the satelite receiver out of the equation. Then just go from there disconecting evertyhing till the hum stops. It could be combination of things in your setup.
    A=Hum still is there after taking out each plug one at a time.
    Do you have to RCA style plugs going into the sub? If so try just using the left (white) one.
    A=The sub only has one black plug. I've tried the black one it came with, a monster plug, a white plug and the red one too.
    Have you tried plugging the sub into an outlet that is on a completely different breaker?
    A=Yes I tried many different plugs and it still hums.
    Anyway, you have several things to check. If NONE of these ideas work, then maybe the connector inside the sub has a bad solder. It happens.
    A=Thank you
    Thanks again to you both. I will let you know what happens when I go and get a new one I guess. It will be over a week because they have to order it.
     
  12. Vince Maskeeper

    Vince Maskeeper Producer

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  13. CRyan

    CRyan Screenwriter

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    Well, we sure do hope this gets worked out. You did a lot of work, and it was not easy replying to our lengthy posts. Do let us know when you get the new one in. I like to have closure. [​IMG]
    C. Ryan
     

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