A Question About Bi-Amping and Bi-Wiring

I have a Denon AVR-3805, Denon DVD-2900, Energy A5+2 (Main Speakers, 2 Main, 2 Rear), Energy AC-300 (Centre Speaker), Energy XL-S12 (Subwoofer).

Supposedly, you can use the Zone 2 outputs on the AVR-3805 to Bi-amp the Main Speakers of the system, giving you (me) 220W to these main front speakers. I have not attempted this.

I do not Bi-wire any of my speakers and I use regular 12 Guage speaker wire.

I use Ultralink interconnects. I have never seen any discussion of Ultralink cables on this forum, so I would be interested in anyone's opinion on them.

Will there be more of an improvement in sound through Bi-amping the main speakers, or Bi-wiring the main speakers?

By the way, I have been paying close attention to the Grover Thread.

Thanking you in advance.

 

I'm a bit confused by your term bi-amp. Traditionally biamping means using an electronic crossover and using separate amps for the low and high frequency speakers. There are obvious advantages to this. Generally the high frequency drivers require less power than the low frequency units. Keeping these systems separate can reduce power requirements, lessen IM distortion and generally is a good thing to do.

Bi-wiring uses the same amplifier but different wire paths for the lows and highs. This has advantages over single wire systems but not as much as biamping. This also requires a speaker system that will accept 2 pairs of wire and route them to the appropriate places. One can also do a form of bi-wiring by just doubling up the speaker wire even though the signal path is virtually identical to the single wire method. This is not too much different than just increasing the effective guage of the wire, but some folks find this beneficial. In fact, I use this method on my main speakers and it does seem to be effective there.

It is also possible to use two full range amplifiers to biamp and not use an electronic crossover. This would also require a passive crossover on the speaker that will take the two feeds and send one to the highs and one to the lows. This would seem to have some of the advantages of traditional bi-amping but would be less efficient due to the losses in the passive crossover. But this will not really increase the power to the speakers in a linear manner. Your woofer will have the same amount of power regardless of what is happening to your high frequency speakers. This method can make the highs sound better though if that amplifier doesn't have to deal with the load of the woofer.

 

Do you feel that way about bi-amping even if you're using two identical amps or only if the amps are different? I could see how using two different amps with their own unique sonic signatures being a problem to make them blend properly but two identical amps shouldn't have that problem.

Vertical bi-amping my B&W's made all the difference in the world and there's no way I'd go back to using one amp. I tried bi-wiring and I really never heard any differences. Bi-amping was immediately noticeable and in every way sounded better to my ears. The highs are less grainy, midrange is less congested, the imaging more precise, the bass is tighter, etc.

 

My Technics SA-DA8 receiver also has bi-amping capability but since my Bostons don't have a dual lows/highs input, I cannot say if it improves the sound any. It seems like a good idea though. BTW: I've noticed many more mid-fi speakers nowadays that are equipped with a dual input. Many of JBL's "Northridge" series speakers that Best Buy sells has this for example. The black E50 model is my favorite.

 

I agree that bi-amping often is usually not as good for hi-fi as it is in PA and hi-powered applications.

Passive crossovers can run the whole gamut. Some are nothing more than a capacitor in series with the tweeter. This cuts the lows out of the tweeter but allows the woofer to run full range. Since most woofers don't have much high frequency response this method can work in some cases.

But passive crossovers can be extremely complex as well. Not only that, but they are often designed as an integral part of the system by the speaker designer. Traditional biamping requires an active crossover before the amplifiers. This totally eliminates the passive crossover that often was designed just for that speaker. These active crossovers are usually designed by different entities and are usually general purpose. So it is not hard to see why many folks prefer using passive crossovers with speakers.

That said, using biamping with subwoofers can be a different deal. In that case all that one is doing is cutting the extreme bottom out of the main speaker. The speaker's integrated passive crossover is still employed. The crossover I use for this purpose is rather unique. It has only a single high quality capacitor in series for the main speaker feed so as far as the main speaker is concerned, it is passive. Of course that means it has only a 6db per octave slope. This is ok because the main speaker has it's own natural low frequency roll off which works in our favor. The low pass output, however, is active and has a higher cut off slope. The thought here is that it is important to heavily limit the high frequency response of the woofer so as to not compromise the full range speaker's low end response. Also since there is no highs in the sub output, the limitations of the active section are not considered that significant.

Now in pa we have a whole different situation. In this case efficiency is paramount. When I started doing PA in the 70's we would use a 3 way electronic crossover. We would use a Crown DC-300A for the woofers, a D-150 for the mids, and a D-60 for the highs. This was significantly more efficient than using passive crossovers. Remember that high frequency content in music is generally much lower than low and mid frequency content. Using a 60 watt amplifier was all we ever needed for the highs and in fact we would usually have to trim the gain to prevent the highs from being too loud.

Here is a link I found that may prove helpful. http://www.audioasylum.com/audio/general/messages/57210.html

 

Doug, thanks for your response.

I found out about "Bi-Amping" the AVR-3805 on Audioholics.com

You have to scroll down a bit:

http://www.audioholics.com/productreviews/avhardware/Denon-AVR3805_review04.php

Steve, thanks for your response.

 

Speaking of complicated crossovers, check this one out for a certain, slightly legendary British speaker: LS3/5 monitor (this is a really good site). And it's only a 2-way speaker to boot.

Crossovers do waaaaay more than many people think they do. I won't go into it here but a properly designed crossover can make a medirocre set of drivers sound decent but a badly designed one can take the best drivers available & make them sound like poo.

 

Hard to tell exactly what they're doing there. There doesn't seem to be any crossover adjustments so that would seem to indicate that both outputs for each speaker would be full range. If so, that would require dual inputs on the speakers so that their internal crossovers could be employed.

 

Doug, thanks again for your time and effort!

It seems to me that there would be no advantage, sound-quality wise, in Bi-amping the AVR-3805. I would be better off trying to Bi-wire my speakers to get the sound-quality boost as you and Steve have mentioned.

 

Hi Doug, I've always understood this as an active system, whereas passive bi-amping, is where you use two separate (usually identical) amps fed with the same signal to drive the treble and bass (as you have described below).

One of the explanations that is often given for the difference, is that the EMF backwash from the treble and the bass of the speaker to the amp is not mixed in the cable.That is the backwash from the bass is not interfering with the treble signal and vice versa.

 

Sort of off-topic but I thought it was informative in an overall way as far as bi-amping is concerned: the Powered Advent

IIRC the woofer's amp generates 60 watts and the tweeter's, 25. Since each amp was optimized for its particular driver, the Powered Advent's final sound output was equivalent to a 125 watt amp driving the unpowered version.