Bi-amping the Denon 3803?

Discussion in 'AV Receivers' started by Elliott Willschick, Jun 9, 2004.

  1. Elliott Willschick

    Elliott Willschick Second Unit

    Joined:
    Dec 1, 1998
    Messages:
    333
    Likes Received:
    0
  2. BrianWoerndle

    BrianWoerndle Supporting Actor

    Joined:
    Feb 19, 2002
    Messages:
    794
    Likes Received:
    0
    Yes, the 3803 has the same multi-zone functionality.
     
  3. Joe Blech

    Joe Blech Stunt Coordinator

    Joined:
    Feb 6, 2004
    Messages:
    58
    Likes Received:
    0
    What about the 3802?
     
  4. Mike Keith

    Mike Keith Second Unit

    Joined:
    Jan 24, 2002
    Messages:
    324
    Likes Received:
    0
    Not without an external active crossover, even then you wont get the full benefit without seperate amps,
     
  5. Elliott Willschick

    Elliott Willschick Second Unit

    Joined:
    Dec 1, 1998
    Messages:
    333
    Likes Received:
    0
    While I may not get the full benefit, is there any benefit to following what the article said to do?

    Thanks
     
  6. Mike Keith

    Mike Keith Second Unit

    Joined:
    Jan 24, 2002
    Messages:
    324
    Likes Received:
    0
    I don't know, I can't tell from the article if it is able to divide the frequency between the tweeter and the mid/woofer. From what I can tell this is more like passive bi-amping, which IMO will not make any difference that could be heard, but hey, give it a try, it might be great.

    The real advantage of true Bi-Amping is the control or dampening over the drivers you gain, having no passive components (caps, coils, resistors) in-between the amp output and the tweeter/midrange/woofer terminals allows for much better control without changing the phase. Also the separate amps power supplies are split, one dedicated to the tweeter and one dedicated to the mids, and so on, this is known as horizontal active bi-amping, and IMO is the best way to gain the most advantages.

    Not enough time to explain all the advantages of true bi-amping, but the link below is a good resource.

    http://sound.westhost.com/bi-amp.htm
     
  7. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    24
    Location:
    NorCal
    Real Name:
    John

    Passive bi-amping DOES work. Separate amps allow far less distortion. In this case, they would be fed off the same power supply and would NOT be truly giving you "240 wpc" as this guy is trying to say (the 110wpc rating is only for stereo, not all channels driven). There would likely be a slight benefit, and you DON'T need an active x-over to achieve it.

    If you remove the passive x-over components, you have essentially destroyed one of the primary characteristics of a given speaker. It's not simply a matter of slopes.
     
  8. Wayne A. Pflughaupt

    Joined:
    Aug 5, 1999
    Messages:
    6,061
    Likes Received:
    25
    Location:
    Katy, TX
    Real Name:
    Wayne
    Perhaps, but this might not necessarily be all bad. With some designs, they load stuff into the crossover to make the drivers “behave” better – i.e., to counteract the negative effects of the other passive elements. And it’s not uncommon for resistors to be added for the sole purpose of padding down either the woofer or the tweeter’s output level, to match the other.

    For instance, my speakers originally had a very low crossover point – 1200Hz – and it was pretty easy to blow the tweeter. A rep sent me a schematic of how to modify the crossover to raise the frequency to 1800Hz. Part of that entailed removing a resistor. I immediately noticed that the bass sounded tighter – hardly a detrimental result.

    Regards,
    Wayne A. Pflughaupt
     
  9. Elliott Willschick

    Elliott Willschick Second Unit

    Joined:
    Dec 1, 1998
    Messages:
    333
    Likes Received:
    0
    Well thanks for all the help. I'll give it a try, for fun, this weekend.
     
  10. ScottCHI

    ScottCHI Screenwriter

    Joined:
    Feb 21, 2004
    Messages:
    1,292
    Likes Received:
    0
    how do you couple the main volume control with zone2's? or can they be linked? seems like it'd be a real pain every time you needed to increase the volume.
     
  11. mackie

    mackie Supporting Actor

    Joined:
    Feb 7, 2004
    Messages:
    568
    Likes Received:
    0
    Elliot - keep us posted on how it works.
     
  12. Elliott Willschick

    Elliott Willschick Second Unit

    Joined:
    Dec 1, 1998
    Messages:
    333
    Likes Received:
    0
    I will. It's been a hectic weekend so I haven't gotten around to getting more speaker wire yet.
     
  13. mackie

    mackie Supporting Actor

    Joined:
    Feb 7, 2004
    Messages:
    568
    Likes Received:
    0
    Thanks - I have a 3803 too. I've been thinking of adding an amp an external amp, but this may give me what I'm looking for much cheaper...
     
  14. ScottCHI

    ScottCHI Screenwriter

    Joined:
    Feb 21, 2004
    Messages:
    1,292
    Likes Received:
    0
    still would like to know how you couple the main volume control to zone2's?

    otherwise you have to change the zone2 volume separately everytime you change your main volume.
     
  15. BrianWoerndle

    BrianWoerndle Supporting Actor

    Joined:
    Feb 19, 2002
    Messages:
    794
    Likes Received:
    0


    That is correct. The 3803/5 was never meant for bi-amping. So even though this work-around works, it is not the most convinent.
     
  16. Elliott Willschick

    Elliott Willschick Second Unit

    Joined:
    Dec 1, 1998
    Messages:
    333
    Likes Received:
    0
    I finally got some speaker wire and tried this out. However, I couldn't figure out how to get it to work. I turned on the zone 2 amps, I hooked up the preamp wires to the CD input (which is not in use normally) but I couldn't get any sound. I can't figure out how to change the input for zone 2. The article states to just press that input but it won't change.

    Any suggestions?
     
  17. Stephen Hopkins

    Stephen Hopkins HW Reviewer
    HW Reviewer

    Joined:
    Jul 19, 2002
    Messages:
    2,598
    Likes Received:
    0
    Passive bi-amping using different channels from the same receiver or amp is not a very good idea unless you NEED to for impedance matching to prevent shutdowns. The reason is that the limiting factor of any receiver/amp is its ability to supply power (current) to the amplification circuitry. Since all 7 channels share one power supply then whether you're using 5 channels or 7 you still have the same current delivery limits.

    Also, if not actively bi-amping, you're send (for example) 100 watts full range to the tweeter crossover and 100 watts full range to the woofer crossover. The tweeter crossover removes the low frequencies and sends (just for example) 50 watts to the tweeter. The woofer crossover removes the high frequencies and sends (again for example) 50 watts to the woofer. So you're forcing your receiver/amp to send 100 watts to the tweeter and 100 watts to the woofer, but both are only seeing 50 watts each. When not bi-amping you're sending 100watts to speaker which then sends 50 watts to the highs and 50 watts to the lows. By bi-amping you're forcing your receiver/amp to work twice as hard to get the same amount of power to each part of the speaker. This can lead to clipping at lower volumes and a higher noise floor. This is pretty simplified but should help explain why passive bi-amping using channels from the same receiver/amp is not a good idea.

    That said, there are cases where passive bi-amping from the same amp/receiver can be beneficial (or even necessary). In my case I use Swans Diva 4.1 speakers (nominal 4ohm impedance) with a Pioneer Elite 43TX which is notorious for not handling 4ohm loads well (possible protection circuitry, not 100% sure why though). By passively bi-amping using the back surround channels I raise the nominal impedance seen by each channel and prevent shutdowns that occur when I try amplifying the speakers each w/ a single channel of amplification. Luckily the 43TX has a setting built in to use the back channels for bi-amping, otherwise I would have the same inconveniences that 3803/3805 users would.
     
  18. Stephen Hopkins

    Stephen Hopkins HW Reviewer
    HW Reviewer

    Joined:
    Jul 19, 2002
    Messages:
    2,598
    Likes Received:
    0
    Passive bi-amping using different channels from the same receiver or amp is not a very good idea unless you NEED to for impedance matching to prevent shutdowns. The reason is that the limiting factor of any receiver/amp is its ability to supply power (current) to the amplification circuitry. Since all 7 channels share one power supply then whether you're using 5 channels or 7 you still have the same current delivery limits.

    Also, if not actively bi-amping, you're send (for example) 100 watts full range to the tweeter crossover and 100 watts full range to the woofer crossover. The tweeter crossover removes the low frequencies and sends (just for example) 50 watts to the tweeter. The woofer crossover removes the high frequencies and sends (again for example) 50 watts to the woofer. So you're forcing your receiver/amp to send 100 watts to the tweeter and 100 watts to the woofer, but both are only seeing 50 watts each. When not bi-amping you're sending 100watts to speaker which then sends 50 watts to the highs and 50 watts to the lows. By bi-amping you're forcing your receiver/amp to work twice as hard to get the same amount of power to each part of the speaker. This can lead to clipping at lower volumes and a higher noise floor. This is pretty simplified but should help explain why passive bi-amping using channels from the same receiver/amp is not a good idea.

    That said, there are cases where passive bi-amping from the same amp/receiver can be beneficial (or even necessary). In my case I use Swans Diva 4.1 speakers (nominal 4ohm impedance) with a Pioneer Elite 43TX which is notorious for not handling 4ohm loads well (possible protection circuitry, not 100% sure why though). By passively bi-amping using the back surround channels I raise the nominal impedance seen by each channel and prevent shutdowns that occur when I try amplifying the speakers each w/ a single channel of amplification. Luckily the 43TX has a setting built in to use the back channels for bi-amping, otherwise I would have the same inconveniences that 3803/3805 users would.
     
  19. mackie

    mackie Supporting Actor

    Joined:
    Feb 7, 2004
    Messages:
    568
    Likes Received:
    0
    Elliot - thanks for trying.
     
  20. mackie

    mackie Supporting Actor

    Joined:
    Feb 7, 2004
    Messages:
    568
    Likes Received:
    0
    Elliot - thanks for trying.
     

Share This Page