Bi-wire vs Bi-amp

[grokit]

"when 7.1 becomes more ubiquitous, I'll invest in a new reciever that offers 7.1 IN ADDITION TO bi-amping the front R/L"

"there simply isn't much effect of bi-wiring without bi-amping. same power going to same speakers."

"If you find this to be the case, there is something wrong."

"the term bi-wire means nothing more than running two sets of wires to your speaker from a single amp. there is no advantage to bi-wiring your drivers. it just wastes wire."

"Bi-wiring is better then single wiring!!!"

"Bi-wiring a speaker is an inexpensive way to improve sound quality by running two identical lengths of wire to each speaker, or purchasing a set of bi-wire speaker cables. Bi-amplifying a speaker is another way to improve sound quality, but is a more expensive option because separate amplifiers are required for the woofer and the midrange/tweeter section of each speakers."

Lots of different opinions here, so here's my 2¢:

There is a much greater benefit to bi-amping speakers that are bi-wire capable than just bi-wiring them, no matter how it is done. Bi-wiring only without bi-amplification will give you the subtle benefits of using higher gauge wire, and from less cross-frequency chatter on the wires that can generate noise and reduce efficiency on an uncompressed system. Bi-wiring speakers that are not set up for it is also possible, but the perceived benefits will be even more subtle, and if you are not careful you can introduce more problems than you will solve.

But some inexpensive HT receivers do the bi-amplification thing very well; my already-discontinued pure digital Panasonic SA-BX500 keeps it's 7.1 intact with the bi-amp feature engaged, because it sacrifices the second room amp, which I don't need anyways. And IMO the extra 7.1 surround channel does add up to a much more immersive experience, even if it's just converted from a 5.1 source by the receiver. And the receiver's internal circuitry does do a great job of separating the lows and highs as it converts the second room amp into the bi-amp and sends the sound directly to the dual binding posts on my Polk towers, which also showed a great improvement.

But if the towers did not have the dual binding posts they could still benefit from the bi-amp/bi-wiring, just less efficiently as the signal gets channeled through the speaker's crossover unnecessarily. This is where problems with mismatched impedances and crossover frequencies can arise. The other place you need a lot of planning is when bi-amping with two different amplifiers, especially when they are mis-matched; it's even easier to screw it up, but the benefits, like with all separate components, can be tremendous.

I was told by a well-known speaker designer recently that any speaker can re-terminate twin (bi-wired) bi-amped leads with two-way single binding posts to benefit from bi-amplification and/or bi-wiring, but I took it with a grain of salt because his speakers are not set up with dual binding posts!

[sabianq]

you know, your speaker designer friend is correct, any speaker array can be bi amped, all you have to do is remove the crossover and put terminals on the cab routed to the HF driver.

line arrays and J-arrays can be set up in this fasion.
each speaker element in active array elements are all now bi and tri amped.
the crossover is electronic and works (processes) on the signal when it is at a line level.
the electronic crossover filters and amplifies/attenuates the line level signal (similar to a graphic EQ) before the signal reaches the systems power amplifiers.

The electronic crossover (depending on its design), filters out a selectable range of frequencies, this allows me to dial in a speakers frequency range and allow me to only send the amplifier a signal exactly taylored to the specifications of that paticular sound driver or transducer.

here are the benifits. if i have a high frequency driver driven by its own amplifier, i can send that amplifier only the frequencies that will be used by that speaker

now the amplifier wont have to work as hard cause it is not amplifing anything under 7 kHz
simillary, the low end amplifier is not amplifying the high end.

also having one speker directly connected to the amplifier as the back emf directly cancles itself out.

when the coil of that speaker moves back and forth in the magnetic field, it generates an electromagnetic pulse which echos back to the amplifier.

if there is only one speaker, that emf is being generated out of phase to the forward emf this cancles.
if you add a second speaker, now you have two back emf going to one amplifier, and the two will be dynamic in phase as the two speakers work to produce two different sounds.

these two out of phase back emfs can cause a signal to become distorted.

using one speaker to one amplifier in any system is the ideal system.


a system would look like this.

mixer>electronic crossover(s)>amplifiers>speakers.


I know that you can change the shape of the sound front by playing with the phase of each element in an array.

its way cool stuff..