1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Bass on terrestial TV

Discussion in 'Subwoofers' started by drago, May 26, 2004.

  1. drago

    drago
    Standard Member

    Joined:
    Apr 22, 2004
    Messages:
    39
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    6
    Location:
    southampton
    Ratings:
    +0
    Hi
    Does anyone know what frequency range is transmitted by terrestial tv transmission i.e. how low is the bass?
     
  2. Nimby

    Nimby
    Member

    Joined:
    Jan 27, 2004
    Messages:
    9,201
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    The Danish Bacon Factory
    Ratings:
    +669
    Good question! I searched for ages but couldn't find the answer online. I looked at tuner specs but that doesn't suggest what is actually broadcast.

    I used to listen to BBC Radio 3 classical organ music. Using two 6th order, series coupled-cavity, bandpass subs which were flat down to 20Hz. I never felt short changed in the deep bass. In fact I built these subs just to listen to these Radio 3 programmes.

    I'm not currently using a tuner so can't confirm anything using my 16-46 PCi which goes deeper.

    Somebody must know the real answer to this one. Perhaps a polite e-mail to the BBC would produce an answer?

    Nimby
     
  3. tHatDudeUK

    tHatDudeUK
    Standard Member

    Joined:
    Dec 27, 2003
    Messages:
    109
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +2
    Using the Nvidia soundstorm utility in conjunction with my Nebula DigiTV PC TV cards I can confirm there is some noises below 50hz as the LFE channel goes up and down (although I don't have a sub in my set-up). I guess it would be more a part of the way the sound is transmitted, which is MPEG layer 2 with a sampling rate of 48khz. I think Bitrate changes from channel to channel but is usually about 192kb/s. Hope this helps.
     
  4. jeff-o

    jeff-o
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Bitrate, whether transmitted digitally or with analog radio, should only affect the upper frequencies. This is because you need to sample an audio wave at a rate of at least twice that of the wave itself. To capture a 20kHz signal, you need a sample frequency of at least 40 kHz. Therefore, to sample 40 Hz, you only need a sample frequency of 80 Hz.

    Any bass you're missing is probably due to the equipment that recorded or is processing that signal, at the transmitter end.

    Don't quote me on this, but I think terrestrial TV is encoded with FM modulation, for a frequency range of 20 to 20 kHz. It may have a maximum of 15kHz though, I need to check my textbooks.
     

Share This Page

Loading...