LG Tv problem with LG 5.1 surround sound

Discussion in 'Televisions & Displays' started by dashburn, Jan 1, 2010.

  1. dashburn Audiophyte

    dashburn
    Joined:
    Jan 1, 2010
    Messages:
    9
    Likes Received:
    0
    I have a lg tv (32lg30) connected to my lg home theater system LHB953 by an optical cable. When watching cable that supports 5.1 surround sound, it will not play on all 5 speakers. It only plays through the center speaker and the left and right speakers. When watching a dvd, the rear speakers are not playing nearly as loud as the center speaker. All the speaker levels are the same. Is there anything I need to change to get 5.1 surround sound through cable and increase the rear speakers?
  2. Adam Audioholic Jedi

    Adam
    Joined:
    Jul 5, 2006
    Messages:
    32,076
    Likes Received:
    11,912
    Location:
    Tucson, Arizona
    Welcome to the forum!

    It's very typical for the rear channels to be quieter than the others. What actually gets played through any of the speakers depends on the mixing of the soundtrack, and most shows put the bulk of the emphasis on the front speakers (left/center/right). So, in general, don't worry about not hearing as much in the rear speakers.

    When you say that "All the speaker levels are the same," do you mean that you set all of the speakers to have the same volume level using the procedure mentioned on page 21 of the owner's manual? If so, then that's great. Using a sound pressure level (SPL) meter is ideal, but doing it by ear is just fine, too.

    Also, what sound mode are you using for TV and for discs? That can affect which speakers get used. I say try the "Bypass" mode with TV and see if any sound comes out of the rear speakers (although not all TV programs have any sound going to the rear speakers).
    Adam,
  3. dashburn Audiophyte

    dashburn
    Joined:
    Jan 1, 2010
    Messages:
    9
    Likes Received:
    0
    I have tried the bypass mode and the 5.1 broadcast is still just from the front speakers. I read somewhere that i need to change the output settings on my tv to dolby digital but that is not an option.
  4. Adam Audioholic Jedi

    Adam
    Joined:
    Jul 5, 2006
    Messages:
    32,076
    Likes Received:
    11,912
    Location:
    Tucson, Arizona
    I didn't get the manual for the TV, yet. Let me look at that and I'll get back to you.
    Adam,
  5. Adam Audioholic Jedi

    Adam
    Joined:
    Jul 5, 2006
    Messages:
    32,076
    Likes Received:
    11,912
    Location:
    Tucson, Arizona
    How are you getting the cable signal? Are you using the internal tuner of the TV, or do you have a cable box? If you have a cable box, how is it connected to the TV?
    Adam,
  6. dashburn Audiophyte

    dashburn
    Joined:
    Jan 1, 2010
    Messages:
    9
    Likes Received:
    0
    I am using the internal cable tuner.
  7. Adam Audioholic Jedi

    Adam
    Joined:
    Jul 5, 2006
    Messages:
    32,076
    Likes Received:
    11,912
    Location:
    Tucson, Arizona
    I certainly could be missing something, but it seems like everything is hooked up and set up properly. As you mentioned, your TV (as far as I can tell) doesn't have any menu settings for the audio output from the optical connection.

    When using the Bypass sound mode, I don't think that you would be getting sound from the front three speakers unless the TV was sending a Dolby Digital bitstream to the receiver. If you were only hearing sound from the front two speakers, then I'd look into it further. As I mentioned initially, audio in the rear speakers is not always there, and when it is, is not typically very loud. It could be that your expectations for the rear audio are different than what exists in the TV shows that you're watching.

    You could disconnect the front three speakers from the receiver unit and then have TV playing in the background while you do other things. If you ever hear any audio at all, then you know that it was from the rear channels. As a note, Dolby Digital does not mean 5.1. Not everyone realizes that. Dolby Digital is an encoding method, and it can carry up to 5.1 audio. My PBS stations are typically in stereo here (even though they are broadcast in Dolby Digital), and I own mono (1.0) Dolby Digital DVDs. That's just more info on why Dolby Digital broadcasts aren't necessarily going to have any audio in the rear channels (or even in the center channel).
    Adam,
    • Like Like x 1
  8. dashburn Audiophyte

    dashburn
    Joined:
    Jan 1, 2010
    Messages:
    9
    Likes Received:
    0
    Thank you for the answer. But what could explain the lack of audio from the rear speakers during dvds? I am able to hear really low levels only if I put my ear up to the speakers. Each connection is connected properly too.
  9. Adam Audioholic Jedi

    Adam
    Joined:
    Jul 5, 2006
    Messages:
    32,076
    Likes Received:
    11,912
    Location:
    Tucson, Arizona
    I'd say check out my first post again and let me know the answer to the question about speaker leveling.
    Adam,
  10. dashburn Audiophyte

    dashburn
    Joined:
    Jan 1, 2010
    Messages:
    9
    Likes Received:
    0
    I changed the speaker volumes in the menu referenced on page 21.
  11. Adam Audioholic Jedi

    Adam
    Joined:
    Jul 5, 2006
    Messages:
    32,076
    Likes Received:
    11,912
    Location:
    Tucson, Arizona
    I'll be happy to check out a DVD if I have it to let you know if you should be getting sound from the rear channels. Which movie(s) are you watching?
    Adam,
  12. dashburn Audiophyte

    dashburn
    Joined:
    Jan 1, 2010
    Messages:
    9
    Likes Received:
    0
    it was Bad Boys.
  13. Adam Audioholic Jedi

    Adam
    Joined:
    Jul 5, 2006
    Messages:
    32,076
    Likes Received:
    11,912
    Location:
    Tucson, Arizona
    Sorry, but I don't have that one. If you have others that you'd like to list, I can check if I have them.

    Air Force One is a good movie to check out the rear speakers, especially the scene when the F-15s first fly out to intercept Air Force One. When the F-15s loop around the plane, you hear the engines loop around the room.
    Adam,
  14. dashburn Audiophyte

    dashburn
    Joined:
    Jan 1, 2010
    Messages:
    9
    Likes Received:
    0
    Alright I will check that one out as soon as I rent it.
    Thanks
  15. dashburn Audiophyte

    dashburn
    Joined:
    Jan 1, 2010
    Messages:
    9
    Likes Received:
    0
    Do you know of any other dvds to test out the speakers in case i cant get this one?
  16. Adam Audioholic Jedi

    Adam
    Joined:
    Jul 5, 2006
    Messages:
    32,076
    Likes Received:
    11,912
    Location:
    Tucson, Arizona
    Hi. I think that there's a thread or two on this forum about that, but I can't recall where. I did a quick Google search and came across this page with some suggestions.

    I'm just so used to it now that I don't really pay attention to which movies are good examples. Air Force One was one of the first that I heard, so it sticks with me. :)
    Adam,
  17. AVRat Audioholic Ninja

    AVRat
    Joined:
    Jun 27, 2005
    Messages:
    3,790
    Likes Received:
    704
    Location:
    Colorado Springs, CO
    To get the rears to a level you like, try playing a CD in PLII Music mode, pg 21 also, and then adjust the rears to your liking.
  18. AVRat Audioholic Ninja

    AVRat
    Joined:
    Jun 27, 2005
    Messages:
    3,790
    Likes Received:
    704
    Location:
    Colorado Springs, CO
    To get the rears to a level you like, try playing a CD in PLII Music mode, pg 21 also, and then adjust the rears to your liking. When watching TV, you might ry using the PLII Movie mode.
  19. twosheds Audiophyte

    twosheds
    Joined:
    Sep 21, 2010
    Messages:
    2
    Likes Received:
    0
    Had the same problem

    Hi, I had the same problem with my new lg flatpanel and the answer is to go to the audio menu, scroll down to .Digital Audio Out and change the output to:pCM
    PCM stands for Pulse Code Modulation. Roughly speaking, it converts the analogue signal to a digital signal that your receiver will handle better.PCM is not a format like .mp3,.cda or .mpg but the name given to the method by which the analogue signal is converted. I had always thought that PCM ment the signal was 2 channel stereo when in fact it is whatever format is passed to the decoder/coder (for want of a better word ?)ie:- DD DD2 DTS 5.1 7.1 blah blah blah you get the picture:) Hope this helps, Cheers S.
  20. gridlock Audiophyte

    gridlock
    Joined:
    Aug 4, 2012
    Messages:
    6
    Likes Received:
    0
    Suround sound Movie proved my sytem worked

    I just joined this forum. I wanted to say that I just got an LG Blue Ray Surround Home Theater System that I have been trying to get to work all day. My left front and right front and the sub woofer was working but not the center or rear speakers. I tried ALL DAY. But after reading some suggestions I found a DVD of "Alice in Wonderland" with Johnny Depp. I said it was in Dolby Digital 5.1 surround sound. So I plunked it in and all my speakers worked great.. So I know my set up is correct, but I am still dissapointed with the results so far.

Share This Page

  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
  • CEDIA