Bi-wire vs Bi-amp

[sabianq]

It has come to my attention that there are some manufactures of equipment that are alowing users to "Bi-wire" their speakers.

no where does it say what the difference between bi-wire and bi-amping is.

just to be a little clear.

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.
as the crossovers in the speaker enclousures still do the same job.

in Bi-amping (which is a completly different animal) you have an individual amp driving an individual driver or driver array.
there is an active crossover in the balanced/unbalanced side driving the amp which shelves the frequencies driving the amp.

so you would in essence have one amp that drives your high tweeters and one amp that drives your woofers.

same with tri or quad amping.

[MrM]

If only you could read Dutch...

Because you are (a bit) wrong

Bi-wiring is better then single wiring!!!

See : http://www.radiostiphout.nl/temp/biwiring.html

I only dropped by for a second, so I haven't read all, but I think this page : http://www.audioasylum.com/audio/cab...ages/4953.html might be helpfull to explain some thought about bi-wiring...

Back to lurking mode, see you all in a few months

[sabianq]

Originally Posted by MrM

If only you could read Dutch...

Because you are (a bit) wrong

Bi-wiring is better then single wiring!!!

See : http://www.radiostiphout.nl/temp/biwiring.html

I only dropped by for a second, so I haven't read all, but I think this page : http://www.audioasylum.com/audio/cab...ages/4953.html might be helpfull to explain some thought about bi-wiring...

Back to lurking mode, see you all in a few months

im sorry, but i totally dissagree with you

the only advantage that bi-wiring a speaker has is that you effectivly double the gauge of the the wire to the speaker.

other that that, there is no advantage (well very little anyway) to bi-wiring a speaker.

read this:
http://sound.westhost.com/bi-amp.htm#bi_wiring

And here is what I base my assumptions on.

In a single-wire, bi-wire capable speaker arrangement you have 1 amplifier and a speaker capable of bi-wired opperation.
this is how you would typically hook up the above mentioned system.


In a bi-wire, bi-wire capable speaker arrangement you have 1 amplifier and a speaker capable of bi-wired opperation.

this is how you would hook up this system.


note the connection at the amp.
There is no difference between a single wire path and a double wire path except for the doubling of the gauge.

images taken from here
http://www.st-andrews.ac.uk/~jcgl/Sc...ire/Page1.html

now lets look at a Bi-amped model.



The advantage is immeditaly apparent.
you have a signal source split going to two active electronic crossovers one being a high pass filter and the other being a low pass filter then the seperate signals are being sent to their own power amplifer with each power amp driving its own driver, one for the tweeter and one for the woofer.

the passive crossover inside of the speaker is taken out or disconnected.

the other advantage is not so apparent

Intermodulation distortion.

When an amplifier is is amplifing different frequencies simultaneously this is called intermodulation distortion and they are most noticable when the delta is very large (like when the amp is amplifing very low tones and very high tones at the same time).

that is why active Bi-amped studio monitors sound way better then non bi amped monitors.

also you run into damping factor

basically, the amplifier can absorb the back pulse (unwanted currents induced by the mechanical resonance of the speaker's voice coil) of a speaker much better if it is just driving a limited frequency range and without a crossover in line.

but i just wanted to show that there is no real advantage of bi-wiring your speakers.

if you want to greatly improve your system the go with bi-amping.
http://sound.westhost.com/bi-amp.htm

[Pipps]

Is bi-wiring beneficial where both the speakers AND the amplifier have twin sets of terminals?

I have a 1995 Sony TAFA30ES Class A amp, and it has those two sets of terminals which I mention.

Would I be wise to take advantage of this? Or is there unlikely to be any noticeable benefit?

[TimmyP1955]

Bi-Wiring definitely sounds better than just using larger wire or a double run. (There are also measurable differences - the trick is in having a sufficiently complex test signal, which "normal" audio measurements do not.) I prefer Linn K400 for Bi-Wiring, as it keeps the pairs separated.

[badaboom]

there is only a slight effect from bi-wiring without bi-amping - same power going to same speakers, separate pathways allow for less "interference" for want of a better word

my Polk Audio Rti10 tower speakers were underpowered until I used my Denon AVR-1907 receiver's bi-amping feature - would be better to have a separate amp, will do that later.

so you don't need two receivers to bi-amp your speakers - many offer bi-amping with one receiver - but the best path is separate amps or a multi-channel amp (they keep each channel more separate than a receiver)

I couldn't figure out why my speakers cost so much...but now they sing. The balance of sound before was weak in front, and the 4 speakers in the back (R/L surround and R/L rear surround) were a drag on the whole thing, giving an unnatural presence of sound. part of that problem is probably the fact that the rear R/L surrounds are not getting distinct information - it is faked by the receiver, borrowed from the r/l surround signals. 7.1 is a joke - but more on this later.

The Denon reciever allowed me to use the internal amps for the rear surround to bi-amp the front r/l. Many 7.1 receivers will let you do this.

if you have speakers that have 4 posts in the back, chances are they really won't sound right until you give them the right power - bi-amped power.

re: losing the two backs - a list of recent blu-ray titles had a very low percentage in 7.1 format, and the Blu-Ray standard isn't even 1/8th of the floor space at blockbuster (a pretty good measure of where things are).

[TimmyP1955]

Originally Posted by badaboom

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. Either your system has a hierarchy problem (poor source on good speakers, for instance), your wire is really poor sounding (many fancy cables sound pretty bad), or you forgot to take the links off the input terminals.

[badaboom]

I think you mis-understood - everything is sounding sweet these days, no problems. my point was running the same Front R/L outputs twice to the speaker - bi-wiring without bi-amping - only offered a slight improvement for me.

what really works beautifully is setting the surround back R/L to front R/L (as my Denon AVR-1907 allows) and running them to the bass posts of the speakers, then running the regular front R/L to the tweeter/midrange posts.

not as good as my next goal - a Emotiva or Outlaw 5 or 6 channel amp is what I'm thinking - but a good start

[TimmyP1955]

Originally Posted by badaboom

I think you mis-understood - my point was running the same Front R/L outputs twice to the speaker - bi-wiring without bi-amping - is pretty useless.

I understood perfectly. My point was if you find this to be the case, something is wrong, as IME the improvement from bi-wiring is quite worthwhile. As is the further improvement from passive biamping.

[badaboom]

ah....but can you compare the difference from bi-amping to that of bi-wiring ?

My experience is that bi-amping made the biggest difference, and it is supported by others in this thread
http://www.hometheatershack.com/foru...tml#post199233

[TimmyP1955]

Originally Posted by badaboom

ah....but can you compare the difference from bi-amping to that of bi-wiring ?

My experience is that bi-amping made the biggest difference, and it is supported by others in this thread
http://www.hometheatershack.com/foru...tml#post199233

but perhaps you're right - I should have said "much better to bi-amp" rather than "useless". for me, the difference was dramatic.

Biamping is certainly better than only biwiring. Just make sure that the gains of the two amps are the same, and that the audio quality of the second amp is at least the equal of the first.

But not everyone with biwire-able speakers can biamp, owing to the limitations of their existing electronics (no preamp output, etc.).

Everyone with biwire-able speakers can biwire, and the difference is worthwhile.

[badaboom]

I just bought a B&W LCR60 center speaker which has four posts....and you're right - sounds better bi-wired (same 2 output posts going to the 4).

Live and learn....

[badaboom]

there are a bunch of 7.1 receivers on the market today that allow the amplification of the rear back speakers to be re-directed to bi-amp the front R/L

re: giving up those back rear channels - who needs faked info there anyway? just gave me a muddied presence with 4 speakers behind repeating 2 channels of information vs 3 speakers up front. Until discrete info for those channels is available in DVD's and digital TV's for us ordinary consumers, you don't need more than 5.1 and the 7.1 setup is a bunch of hype to sell more receivers.

from what I understand from you pros out there, getting a separate amp is better...but for us folks who aren't really into a separate amp purchase, bi-amping using one receiver is a middle ground that, at least for me, did wonders...way beyond bi-wiring.

Denon AVR-1907 7.1 receiver
Polk Audio Rti10 fronts
Polk Audio CS2 center
Mirage Nanosat Prestige Surround

[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 and arrests the speaker coils inertal resonance more effectivly.

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 an HF driver to become distorted from the EMF of the LF driver.


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..