[garion]

Since my last message was past over, I'll try again.


I'm a bit new to some of this higher end stuff, and I'm wondering if some of you guys could answer a couple questions:


1. Bi-wiring: They say that bi-wiring improves the sound of speakers (that are capable of it), because the high end and low end are seperately wired to the receiver. So we have 2 pair of wires going to the receiver. But when they hit the receiver, they are merged into a single connection again.... How can this improve the sound?


2. My receiver (Onkyo TX-906 approx 8years old) has an A/B switch.. I believe the A connection has 75 Watts and the B has 35 Watts (I lost the owners manual so I'm not sure..) If I hook up the bi-wire speakers so that the low is on the A and the high on the B (effectively bi-amping), am I going have problems? Is going to affect the sound quality?


THanx in advance guys!

 

[madcowz]

I never really understood the concept myself. I mean, isn't the job of 'seperation' (hi's from low's) the job of the amp? How does the amp know you're biwiring/amping? In the case of biwiring, the amp is sending the same signal to both wires in each channel, so highs lows and mids will remain in both sets of speaker wires... how is this effective? Perhaps splitting the signal to two different wires will put less stress on each, making it more efficient? But still, the signal to each wire is effectively weakened, so not like you'd be getting more current...


Now In the case of biamping, you have the same case again, where each amp is sending the same low-mid-hi signal to each cable... the only way I can see separation occuring is if you set a frequency cut-off on one of the amps (for lows) and setup the 2nd amp to send only the higher frequencies


Now can someone clear up some of the confusion for me?

 

[Ross E]

Though I am no expert I will try to explain both (as I understand them). I run my front speakers and center channel bi-amped, and my rear and sides bi-wired.


First, Bi-amping:


Set-up:


Basically using 2 channels of amp power for each speaker. In my case I run (1) 2 channel Acurus amp for each speaker. One channel drives high and one channel drives low frequencies. You must use a preamp, amps and an external active crossover to do this. Simply connecting the high and low posts on a speaker to the separate channels isnt effective Bi-amping.


Benefits:


The signal coming from the preamp, is split at the crossover into 2 or 3 separate signals (high and low or high, low, mid). Noticable benefits to me, are the amps run much cooler...and efficiently since they are only dealing with a limited frequency range. My amps...when running as loud as I can stand...only get "lukewarm" to the touch. When running at a normal listening level are barely warm at all. Secondly, The active crossover is much more accurate than the built in crossover in the speakers. When I first went to Bi-amping, I noticed an extreme improvement in sound.



Bi-wiring:


Basically like stated in the post: running a separate wire to each post on the back of the speaker. Supposedly, the high and low frequency will travel down a separate wire to the speaker. Sound improvement? I'm not sure if there really is much. Its one of those "maybe its a little different" kind of things..Like you want to hear an improvement because you just spent a small fortune on another length of speaker cable.


I don't want to start a flame war.....but IMHO bi-amping makes a huge sound difference, and bi-wiring...well I do it (on my rear and sides, because it is supposed to sound better


Hope this helps


Ross

 

[Stasis]

Do Not "bi-amp" using channels A & B. Among other issues, keep in mind that the "B" button does not activate another amplifier,

but patches in another set of speakers to the "A" pair. It is very likely that a reduction in power on both channels takes place when the receiver is switched "A+B". If you bi-wire to "A", you will drop impeadence (ohms) and the unit will increase power output instead. By how much depends on Onkyo. Give it a shot, you may the results.

 

[Andy Lammer]

With bi-wiring you will be using 2 sets of speaker cables.

So there is 2x the conductor for the signal to flow through.

This may be important if you are using a small guage wire to begin with.


Those cheap thin flat metal speaker binding post jumpers are generally poor sounding. So anything that eliminates them is a good thing ... such as bi-wiring


- Andy

 

[Brian Vaughan]

Here are a couple of good articles on the benefits of bi-wiring and bi-amping. I've been debating whether to bi-wire my B&W 804s, but I haven't decided to take the plunge yet.


Here they are:
http://www.soundstage.com/synergize/synergize031998.htm

http://sound.westhost.com/bi-amp.htm#contents

 

[catapult]

I agree with Ross that bi-amping done right requires you to bypass the speaker's crossover network and use an active crossover between the preamp and power amps. One reason passive crossover design (like in most speakers) is so hard is because the drivers change impedance with frequency. Your 8 ohm woofer might actually vary between 5 and 50 ohms at different frequencies. It's easy to design a filter for a constant impedance but hard to design for one that changes. If you put the crossover before the power amps, it is working into a constant impedance and it's much easier to design one that works like you want.


Bi-amping and using the built-in crossover is a much more subtle improvement. Mostly, it allows the woofer amp to clip without letting the resulting high frequencies of the clipped square wave to get into the tweeter. The high frequencies are filtered out of the woofer signal, and the woofer doesn't reproduce them as well anyway, so the clip doesn't sound as harsh as if they were accurately reproduced by the tweeter. Of course, a better solution is to use amps powerful enough that they don't clip in the first place.


Bi-wiring with a single amp? Well, some people claim they can hear the difference and others claim they can't. If you can do it without it costing an arm and a leg, it probably doesn't hurt anything but, if you are on a budget, I think it's probably better to put the money into better amps that won't clip. YMMV.

 

[Horton]

Hi everyone.

I just installed Bettercables biwire cables to my Def Tech front speakers, based on several positive recomendations, including from the manufacturer. This seemed to open up the high end, which is otherwise restricted on these speakers. I love the difference.


I was able to improve the low end just by carefully moving the speakers around and monitoring frequency sweeps. These relatively inexpensive changes have made a huge total difference in the sound of my system. My next improvements will take significantly more money for improved equipment!


Horton

 

[catapult]

Hi Horton,


Glad you like the new sound. You have really changed 2 things - the cable type (Bettercables) and the connection method (bi-wiring). To see if bi-wiring makes any difference by itself, you could leave your new cables just like they are and put the speaker jumper straps back in place so you are running the new cables mono-wired. Many people find the difference, if any, to be subtle.

 

[madcowz]

The case of biwiring is still yet unsettled. What I want to know is if the difference is in high-low separation, or b/c you are getting twice the conductance for the signal. I just don't see how the highs could be separated from the lows when both wires are plugged into a single post in the amp/receiver. And for the case of the higher conductance, that shouldn't matter unless you have a super long run of cables or you were using high-gauge stuff to begin with. My fronts are biwirable, but it's a 2-3 meter run and I'm using 12 gauge anyway. So is there ANY point in biwiring at all, or is it just a waste of money? Someone please explain how separation can occur in biwiring (not biamping), and perhaps then I will become a believer.

 

[Andy Lammer]

Why does anyone need written proof ?

Though the scientific testing and conclusions are of interest to us all. We all like to know why/how stuff works.


If the written proof says that you will hear an improvement and you don't ... then what ?


If the written proof says you will not hear an improvement and you do ... then what ?


Pick up some cheap 10 guage ( a few dollars ) and try it on your bass drivers, and let you ears decide


- Andy

 

[Andy Lammer]

Another slant to the topic, but I am not 100% sure of it


By removing the jumpers that join the 2 sets of binding posts, one is eliminating the other driver's cross-over components from the driver. That is, the signal going to the top end, does not traverse the caps/inductors/resistors of the bass drivers. Now I could be wrong on the influence of a cross-over in parallel. Any thoughts if this is true ?


- Andy

 

[catapult]

Andy, I don't think it works that way. You're just replacing a short jumper with a long one (twice the cable run.) Electrically, the crossover highpass and lowpass filters are still connected in parallel either way.


Madcowz, while the voltages on both wires will contain all frequencies, the current flow will be separated into high and low paths because that's what the crossover filters are letting through at the other end. In theory, you could have a wire more suited to carrying the highs hooked to the tweeter and one more suited to carrying lows hooked to the woofer. Of course we all know reality doesn't always conform to our pet theories.


My take on the great wire debate is it's impossible to generalize about which wire is "best" for everybody. It depends too much on your amp and speakers, not to mention your listening room. Different wires do have resistance, inductance and capacitance properties so they have the potential to interact with your system to make it sound different. It may sound better or it may sound worse. The wire might be less "accurate" but it might correct some deficiency in your system to make it sound better. IMHO, many of the highest priced wires are just fancy tone controls. Somehow, having a tone control on your preamp is evil but doing the same thing with a $5000 wire is acceptable. Go figure.

 

[Delicious2]

The most well reasoned explanation that I have found as to why bi-wiring may make a difference was written by Jon Risch.

http://www.geocities.com/jonrisch/biwiring.htm


I have a pair of Alon IVs in front which supposedly greatly benefit from bi-wiring, even tri-wiring. I currently (pun intended) have them bi-wired with 20' of some old Monster speaker cable, but, I plan to try a tri-wired DIY harness made out of braided CAT5. I can't afford the special speaker cable made by the speaker manufacturer Acarian, especially in a tri-wired 20' configuration.


Mark Haskins

 

[jakehall]

Quote:

Originally posted by madcowz I just don't see how the highs could be separated from the lows when both wires are plugged into a single post in the amp/receiver.

This concept is a bit counter-intuitive but makes sense from a circuitry perspective. Even though the cables are connected to the same power supply, the total circuit for each cable is different, allowing one cable to carry a different signal from the other. Basically, you end up using the crossover in the speaker for the whole cable run instead of just inside the speaker.


The only real change that happens is length of cable carrying the full range signal. Without bi-wiring the wire traveling all the way from the receiver to the binding posts carries the whole signal while biwiring means the signals are together only while in the amp & processor.


jake