Bi-Amping Question

Discussion in 'Archived Threads 2001-2004' started by Todd_RIC, Mar 19, 2003.

  1. Todd_RIC

    Todd_RIC Stunt Coordinator

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    Hi guys,

    I'm sure this is a stupid question, but if I were to set up a 7.1 system using two 5 channel amps (I would bi-amp the three fronts), how would I hook up the three extra channels to the preamp?
     
  2. JohnnyG

    JohnnyG Screenwriter

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    (deleted after Cees pointed out that I don't read too well. I blame it on a cold [​IMG])
     
  3. Cees Alons

    Cees Alons Moderator
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  4. Jonathan M

    Jonathan M Second Unit

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    First this is passive biamping right? (You are not replacing the xover on the speakers)

    Hook it up as follows:

    Rear 4 channels from preamp to 4 channels on amp 1.

    Split the 3 front channels with y-splitters and send them to the amps as follows:

    Centre1 -> amp1 input 5
    Centre2 -> amp2 input 1
    Left1 -> amp input 2
    Left2 -> amp input 3
    Right1 -> amp input 4
    Right2 -> amp input 5

    Then send output of channel 5 of amp 1 to the centre woofer section,
    Output of channel 1 of amp 2 to the centre tweeter section,
    Output of channel 2 of amp 2 to the left woofer section,
    Output of channel 3 of amp 2 to the left tweeter section,
    Output of channel 4 of amp 2 to the right woofer section,
    Output of channel 5 of amp 2 to the right tweeter section.

    A receiver can do this if it has main in's as well as pre-outs. (eg NAD T752/762, H/K520 etc.)

    Make sure that amp1 and amp2 have the same amount of gain (If they are the same model that would be even better).

    You will get even better performance if you actively biamp, but this requires a LOT of knowledge to get right, as you are replacing the passive xover with an active one, and many active xovers do not incorporate the acoustic transfer functions of each driver, or baffle step compensation etc. (Mind you, nor do a lot of passive xovers in main stream speakers!)

    Hope this helps
     
  5. BrentPollard

    BrentPollard Second Unit

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    I have done passive bi-amping in the past and IMHO I heard no real difference. If you don't yet have the two 5ch amps don't even bother. I would suggest using one 5ch amp for the four surround and the center and get a good 2ch for the fronts.[​IMG]
     
  6. Charles Gurganus

    Charles Gurganus Supporting Actor

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    Brent, many do passive bi-amp and hear a difference. I sure do. Of course the speaker is the key. If you have a speaker with 91db and 8ohms ratings, no, biamping may not be as noticable. With speakers like my NHT VT2's 86db and 6ohm (dipping to 4ohms), biamping is more useful. [​IMG]
     
  7. Ron-P

    Ron-P Producer

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    Here is a good read on vertical and standard bi-amping.

    http://www.symphonysound.com/articles/biamp.html

    I have 4 Adcom 2-channel amps, 3 of which bi-amp my mains ( Polk RT55's) and my center (Polk CS400). I use one amp per speaker. The right channel powers the tweeter's and the left channel powers the driver's. The 4th amp powers the surrounds. I wired up my rig in a vertical, passive set-up. It saves on interconnect costs and I did not want to change out the factory x-over's.

    I was using my Marantz SR5000 (75wpc) to run the rig. Invested in these Adcoms GFA-535's (60wpc) and went directly into a bi-amp set up. Between going with separate amps and bi-amping there is a huge difference in sound quality.


    Peace Out~[​IMG]
     
  8. BrentPollard

    BrentPollard Second Unit

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    Point well taken.[​IMG]
     
  9. Vince Maskeeper

    Vince Maskeeper Producer

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    There is also some real basic information in the FAQ AND PRIMER as to the different modes of Biamping and biwiring.

    -Vince
     

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