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Bi-amping the Denon 3803? (1 Viewer)

Mike Keith

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Jan 24, 2002
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Not without an external active crossover, even then you wont get the full benefit without seperate amps,
 

Mike Keith

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Jan 24, 2002
Messages
324
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
 

John Garcia

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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.
 

Wayne A. Pflughaupt

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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
 

ScottCHI

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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.
 

mackie

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Feb 7, 2004
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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...
 

ScottCHI

Screenwriter
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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.
 

BrianWoerndle

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Feb 19, 2002
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794


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.
 

Elliott Willschick

Second Unit
Joined
Dec 1, 1998
Messages
333
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?
 

Stephen Hopkins

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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.
 

Stephen Hopkins

HW Reviewer
Senior HTF Member
Joined
Jul 19, 2002
Messages
2,604
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.
 

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