bi amping

Discussion in 'Archived Threads 2001-2004' started by Steven Hallett, Feb 7, 2002.

  1. Steven Hallett

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    i have a onkyo 898 set up with 7.1 ,first what is biamping second can it bedone with this amp if so will it make a differance
     
  2. Vince Maskeeper

    Vince Maskeeper Producer

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    Steven,
    I'll take a shot:
    1) True Active Biamping: This is when you have an active crossover unit between your preamp and amplifier which splits the signal coming out of the preamp into a Hi and Low freq signal. These split signals are then fed to 2 seperate amps (or 2 different channels on an amp) and amplified completely seperately. This way your Hi and Low stay completely seperate from the very beginning... and they get amplified seperately, and passed down a dedicated speaker cable for each...
    When these 2 signals are fed into a speaker, they must go into a speaker wired to accept 2 discrete signals.
    This is true biamping- and it is very rare in Home Theater applications. It is ideal as it keeps the freq discrete starting before amplification - and gives you better control. You find this type of setup in professional PA systems, Theaters and some studio monitoring situations
    2) Passive Biamping: This is where you don't have an active crossover unit to split the signal and instead you feed fullrange signal into two amplifiers (or 2 amp channels).
    These full range signals are amplified seperately and then fed each on their own wire into a speaker designed to accept 2 discrete full range signals.
    A passive crossover filter inside the speaker filters out the High signal from the material destined for woofer and filters out the Low signal from the material destined for tweeter. This crossover circuit inside the speaker is not connected between the HI and LOW- so each band pass is essentially "discrete" after the amplifier: it is just filtered after it is amplified (where as in #1 it was split before being amplified).
    Is also is uncommon in HT- although more common than true biamplification. This requires that you have 2 amps (or amp channels) to drive each speaker- and that the speaker is equipped to be wired this way.
    This gives a full amplifier channel dedicated to Hi and one Dedicated to low: giving more power to each driver and resulting in a sonic improvement.
    3) Biwiring: This is where it gets sticky. You run 2 speaker cables from a single amp channel and hook that to 2 inputs on the speaker. If you have special speakers designed to accept this (like the ones explained above), The passive crossover filter inside the speaker filters out the High signal from the material destined for woofer and filters out the Low signal from the material destined for woofer.
    As above, this circuit is not connected inside the speaker- so each band pass is essentially "discrete" after the amplifier- however since they share a single amp channel-- they are connected at the amplifier.
    I am not a fan of Biwiring- as I believe it is nonsense (however some here will certainly argue otherwise). The advantage of discrete signal chain is killed when the speaker wires share an amp channel... You no longer get more power to the drivers, and no longer have discrete signal. Electrically speaking, there is very little difference from this vs just feedign a single fullrange signal to the speaker and letting it split it.
    Usually any improvement in sound from BIWIRING seems to be the result of the fact that you're using 2 speaker wires (thus doubling the volume of signal wire).
    I'm not familiar with the unit in question- but True biamping requires a seperates system with an active crossover. If you wish to experiment with Passive Biamping, or Biwiring- you have to make sure you have "biwire" type speakers which allow you to remove the jumper inside the crossover and run 2 speaker lines to the speaker.
    Hope that makes sense. Hopefully one of the fans of BIWIRING will drop in and offer a counterpoint to my assessment of the idea.
    -V
     
  3. Philip Hamm

    Philip Hamm Lead Actor

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    Vince, there's no need to discuss biwiring, it has absolutely nothing to do with bamping.

    Steven, the only way you could biamp (passive biamping as described in Vince's article) would be if you bought two identical 7 channel power amps and used your Onkyo as a preamp. Would it make a difference? Likely!
     
  4. Vince Maskeeper

    Vince Maskeeper Producer

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  5. Rob Warren

    Rob Warren Auditioning

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    Steven,
    To bi-amp, your reciever would need pre-amp outputs. It probably does, the real questions would be, what kind of speakers do you have, and are you willing to purchase a 2-way stereo cross-over and 2 stereo amplifiers?
    Your speakers would need to be bi-ampible. Do they have separate LF and HF inputs? If you have to alter the wiring internally to create these separate inputs, then make sure you know what your doing. [​IMG]
    I could go on as to reasons for bi-amping but this post would be way too long. In short I will say, personally, I would not bi-amp a HT system unless all of my components were of audiophile quality. Hope this helps.
     

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