+ Post New Thread
Page 2 of 2 FirstFirst 12
Results 16 to 25 of 25
AV and Multimedia Related Thread, Hummmmmmmm from speakers in Technical; Originally Posted by Koldov Think this is the 'ground lifting' mentioned, some of the more expensive boxes have a switch ...
  1. #16

    CESIL's Avatar
    Join Date
    Nov 2006
    Location
    Hampshire
    Posts
    1,405
    Thank Post
    109
    Thanked 267 Times in 198 Posts
    Rep Power
    169
    Quote Originally Posted by Koldov View Post
    Think this is the 'ground lifting' mentioned, some of the more expensive boxes have a switch that does it for you it appears.

    I'm still concerned it is described as a loud 'howl' by the op though, then a 'hum' in the thread title...

    Kol.
    Well Hum or Howl...it is difficult to describe the sound in words

    It is not just the usual low level background 'hum' and not a feedback squeal. I guess I could try recording it later?

  2. #17

    CESIL's Avatar
    Join Date
    Nov 2006
    Location
    Hampshire
    Posts
    1,405
    Thank Post
    109
    Thanked 267 Times in 198 Posts
    Rep Power
    169
    OK so I cut about 0.5mm of the insulation from around the base of the pin and hey presto...noise is gone!

  3. Thanks to CESIL from:

    mac_shinobi (24th October 2013)

  4. #18

    mac_shinobi's Avatar
    Join Date
    Aug 2005
    Posts
    10,053
    Thank Post
    3,585
    Thanked 1,123 Times in 1,025 Posts
    Rep Power
    377
    Quote Originally Posted by CESIL View Post
    OK so I cut about 0.5mm of the insulation from around the base of the pin and hey presto...noise is gone!
    Base of what pin - earth pin on the three pin plug or what exactly ?

  5. #19

    CESIL's Avatar
    Join Date
    Nov 2006
    Location
    Hampshire
    Posts
    1,405
    Thank Post
    109
    Thanked 267 Times in 198 Posts
    Rep Power
    169
    Quote Originally Posted by mac_shinobi View Post
    Base of what pin - earth pin on the three pin plug or what exactly ?
    Nothing that drastic...

    0.5mm of insulation from the base of the jack plug pin on the audio cable...

    Not even I would mess with the mains plug

  6. #20

    john's Avatar
    Join Date
    Sep 2005
    Location
    London
    Posts
    10,447
    Thank Post
    1,537
    Thanked 1,069 Times in 934 Posts
    Rep Power
    305
    Quote Originally Posted by crc-ict View Post
    Good call on the solution, but heck that is expensive!

    Try this one from CPC:
    A-1095 - UNBRANDED - GROUND LOOP ISOLATOR. | CPC

    Much more bearable price :-)
    I have used the above in many installations and temp setups with ground loops and all problems with audio humm were solved, you don't need an £80 box for that job usually

  7. #21

    mac_shinobi's Avatar
    Join Date
    Aug 2005
    Posts
    10,053
    Thank Post
    3,585
    Thanked 1,123 Times in 1,025 Posts
    Rep Power
    377
    Quote Originally Posted by CESIL View Post
    Nothing that drastic...

    0.5mm of insulation from the base of the jack plug pin on the audio cable...

    Not even I would mess with the mains plug
    Any chance of some photos @CESIL ??

  8. #22
    Koldov's Avatar
    Join Date
    May 2011
    Location
    Bedfordshire
    Posts
    568
    Thank Post
    129
    Thanked 65 Times in 52 Posts
    Rep Power
    42
    I second the photo request @CESIL and just out of interest, may I ask what brought you to that conclusion?

    Kol.

  9. #23

    Join Date
    Jan 2008
    Location
    South West
    Posts
    1,842
    Thank Post
    219
    Thanked 271 Times in 219 Posts
    Rep Power
    70
    I've experienced the hum, 'sometimes' if you don't have the manufacturers software installed the sound card won't change to the correct output mode. it will treat every device on the audio out as "headphone" but with the manufacturers software, Realtek in my case, you can see it switch the output to "line". When it does this the ground loop issue goes away.

    I've seen this with sigmatel as well.

    This issue has hit me more recently as we've moved to windows 7 that normally has the right sound drivers in already. So we didn't bother with the manufacturers version. Whereas on XP we had to install it.

  10. #24

    CESIL's Avatar
    Join Date
    Nov 2006
    Location
    Hampshire
    Posts
    1,405
    Thank Post
    109
    Thanked 267 Times in 198 Posts
    Rep Power
    169
    Sorry for the slow reply folks, but I was not at work last week...

    For those who wanted to know what the fix was I have produced a natty illustration which will show it better than a photo...
    audio plug.jpg
    @Koldov...I found that pushing the plug very firmly up against the laptop socket stopped the noise and that suggested that that there may be a contact problem...

  11. #25
    Koldov's Avatar
    Join Date
    May 2011
    Location
    Bedfordshire
    Posts
    568
    Thank Post
    129
    Thanked 65 Times in 52 Posts
    Rep Power
    42
    Ah I can see now what the earlier description meant (I was thinking you were stripping insulation from the cable, hence the wut?). Luckily, your natty little illustration explains things very clearly (a picture paints a thousand words...) Thank you.

    Kol.



SHARE:
+ Post New Thread
Page 2 of 2 FirstFirst 12

Similar Threads

  1. High pitched noise and smoke from speaker...
    By pslater in forum AV and Multimedia Related
    Replies: 2
    Last Post: 5th June 2013, 04:57 PM
  2. Replies: 8
    Last Post: 11th January 2013, 03:16 PM
  3. Replies: 1
    Last Post: 17th January 2011, 03:36 PM
  4. Accessing work from home.
    By eejit in forum Windows
    Replies: 33
    Last Post: 1st June 2007, 02:47 AM
  5. Strange beeping from speakers (laptop)
    By thecossack in forum Hardware
    Replies: 2
    Last Post: 13th December 2006, 03:11 PM

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •