1. Join Now

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

Cross-over frequency?

Discussion in 'AV Receivers & Amplifiers' started by Dr.Rock, May 31, 2005.

  1. Dr.Rock

    Dr.Rock
    Active Member

    Joined:
    Jan 10, 2002
    Messages:
    620
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    London, UK.
    Ratings:
    +10
    On the setup of my Denon 2802 amp, I set all my speakers (including mains) as "small", and the the crossover frequency as 80 Hz. In theory, that should mean that anythign less than 80 Hz should go through the subwoofer instead of the speakers.

    However, when I play a 60Hz test tone (downloaded from SnapBug website) through my amp, I am also getting the tone coming from the speakers and not onyl from the subwoofer. I would've thought this would've been seprated from the speakers.

    Any advice greatly appreciated.

    Thanks,

    Sarmad.
     
  2. eviljohn2

    eviljohn2
    Well-known Member

    Joined:
    Jul 8, 2002
    Messages:
    7,529
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Near London.
    Ratings:
    +208
    The crossover frequency isn't a "brick-wall" filter but represents where the gradual roll-off is at first evident (the -3dB point usually but it depends how a manufacturer implements it) so what you're hearing is right. It would sound very odd if there was such an abrupt switch from speakers to sub rather than gradually shifting the output between the 2. :)
     
  3. alexs2

    alexs2
    Well-known Member

    Joined:
    Nov 13, 2002
    Messages:
    13,896
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Ratings:
    +1,674
    Hi there...doesnt quite work like that...the crossover isn't a brickwall in that all frequencies above a certain frequency go to one driver,and vice versa.....most such filters have a roll-off,in other words at the crossover point,frequencies below are gradually sent to the LF unit,and so on for those above.

    This explains why you will hear LF tones from your speakers,but with diminishing level as the frequency decreases.

    Very high order(in other words sharp filters) crossovers can have quite nasty audible effects,hence the use of more gradual crossovers.

    LOL...eviljohn...you beat me to it!
     
  4. eviljohn2

    eviljohn2
    Well-known Member

    Joined:
    Jul 8, 2002
    Messages:
    7,529
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Near London.
    Ratings:
    +208
    :laugh:
    Yup, but yours was better as I didn't comment on cascaded filters like you did! :)
     
  5. alexs2

    alexs2
    Well-known Member

    Joined:
    Nov 13, 2002
    Messages:
    13,896
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Ratings:
    +1,674
    Most kind!...a topic fresh in my memory after setting up the filters on an AV32R/DP(digital,I know,but taught me a lot about the effects of filters!)
     
  6. balders

    balders
    Active Member

    Joined:
    Jul 31, 2001
    Messages:
    451
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    28
    Ratings:
    +25
    It's also worth checking that your amp isn't in "Direct" mode as this feeds the frequencies below the crossover to the sub AND the mains. Took me half an hours worth of test tones and head scratching before noticing :suicide: .

    Balders.
     
  7. Eddy Boy

    Eddy Boy
    Active Member

    Joined:
    Dec 9, 2004
    Messages:
    937
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    28
    Location:
    London
    Ratings:
    +27
    You also want to set the crossover so that all speakers are covered, so lets say the fronts go downt 70 and the surrounds to 120 and the centre to 90 then set the crossover to 120, some amps allow you to set indivdual crossover settings for each set of speakers.
     

Share This Page

Loading...