cross over frequency

Discussion in 'General Electronics Chat' started by ninjaman, Nov 29, 2013.

  1. ninjaman

    Thread Starter Member

    May 18, 2013

    the cross over frequency. it usually has a -3dB drop. what are the problems if it doesn't have a -3dB drop
    the circuit is a third order butterworth for both low and high pass.
    I know that if the two signals are in phase then the phases add meaning there is a peak. but im not sure how to best word this. and what the consequences are

    if any could help I would appreciate it

  2. tubeguy

    Well-Known Member

    Nov 3, 2012
    The crossover point may be considered to be at the -3db point.
    Are you thinking of the slope of the filter?
    3rd order filters just have a steeper slope, than a first or second order filter.
    The -3db point is still the -3db point.

    For a speaker crossover some think out of phase at the crossover point is preferred. And sometimes it's useful to have different Hi-pass and Lo-pass crossover points to deal with uneven speaker frequency response.
    A steeper slope, especially on a speaker Hi-pass is sometimes beneficial to keep excessive low frequency energy out of a HF driver (tweeter)
    Last edited: Nov 29, 2013