H/K AVR 525 - Does the Triple Crossover really work or false advetising?

Discussion in 'AV Receivers' started by Tom_Mack, Apr 16, 2003.

  1. Tom_Mack

    Tom_Mack Stunt Coordinator

    Joined:
    Dec 11, 2000
    Messages:
    233
    Likes Received:
    0
    I just bought the H/K AVR 525 and although I am happy with the sound overall the Triple Crossover doesn't seem to work as advertised to me...

    There are settings for the mains, center, surrounds and sub frequencies. I set the mains to 60 HZ and the center and surrounds to 80Hz. There is no mention of the sub setting in the manual, but I found an insert on the H/K web page saying to set the sub setting at least as high as the speakers highest setting (in this case 80 HZ) or else there will be a gap for that speaker set.

    To me, I read this as set the sub setting to the highest frequency the sub can go. I set the sub frequency to 120Hz.

    Now on all channels the bass begins at 120Hz and is doubled until the crossover setting for that speaker! If I set the crossover setting to 80Hz, there is no double bass on the center and surrounds, but the mains have double bass from 60 to 80Hz! If I set the sub to 60 Hz, the center and mains have a gap from 60 to 80Hz!

    Is this the way the triple crossover is supposed to work!!!

    Please reply, so I know if my receiver is broken or not!

    Thanks!
     
  2. Jonathan M

    Jonathan M Second Unit

    Joined:
    Jul 23, 2002
    Messages:
    267
    Likes Received:
    0
    Hi Tom,

    How did you measure this, with an SPL meter, or by ear with test tones? The main problem with this is that it is effected by the room and the speakers' rolloff etc. It will give you an idea of what's happening, though.

    A better way to test is to measure the voltage out of the pre-outs when playing an appropriate signal. This is best done by playing a signal that looks like music, and covers the entire audio band. An MLS signal is perfect. Then, you record the output onto a computer as a .WAV file (Using the sound card in and whatever the default sound recording software is - make sure no EQ is going on.) Then do a frequency measurement on this recorded .WAV file to see what is happening with the Bass Management. I have test tones (In DD, PCM and DTS) if you're interested.

    Bass management using different xover frequencies is fraught with problems IMO with phase and how signals sum. My recommendation is to set all the xover frequencies (Mains, surrounds, sub) to the same point. It eliminates a LOT of problems.

    Hope this helps
     
  3. Tom_Mack

    Tom_Mack Stunt Coordinator

    Joined:
    Dec 11, 2000
    Messages:
    233
    Likes Received:
    0
    Jonathan -

    Thanks for the reply. I was measuring the output with an SPL meter when I realized there was too much bass being output.

    I did exactly what you said already: Set all speakers to 80Hz crossover. To me, it just doesn't seem to be working as advertised. I was hoping to have the mains at 60Hz and the rest at 80Hz, but if this is causing double bass or phase problems it is just not worth it.

    Tom
     
  4. JohnnyG

    JohnnyG Screenwriter

    Joined:
    Dec 18, 2000
    Messages:
    1,522
    Likes Received:
    0
    Tom, with the original setting as described in your first message, your mains and sub will both be playing tones between 60 and 80Hz. so that accounts for the increase in bass response. If they were out of phase, you'd see a drop in bass response, so you're okay there, but you may have a in-room response peak in that frequency range which exaggerates those frequencies, which would not be good.

    As always, just do what sounds best to you. Set the mains to 60 and others to 80, adjust the levels with your SPL meter and listen to some material. Then set the mains to 80Hz too, reset the levels with the SPL meter and listed again. Whatever sounds better to you, wins.
     

Share This Page