What does the crossover do differently when you bi-wire?

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river251

river251

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Joined 2010
#1
It just occurred to me.

Biwire: put the bass signal on the woofer, the highs on the tweeter. All done. Each part of the speaker gets what it does best.

BUT.......is the crossover still in the picture? It can't tell you are biwiring. So how is a crossover designed for biwiring? It's getting the same signal if you single-wire, and use a jumper, as it does if you biwire. So at the speaker, biwiring = singlewiring.

But, biwiring does give you the advantage of sending the highs across the room on the high wire, and the lows across the room on the low wire, so there is less congestion and interference.

No, at the amp both wires are getting the same signal, so ALL the signal goes down the high wire and it all goes down the low wire. And when they get to the speaker, they go into the crossover exactly as they would if you single wire with a jumper.

So what the heck is biwiring about?

Thanks =]

Jim
 
#2
I had a EE explain it to me once (there are two in my family). But I dont remember his explanation well enough to pass it on. I can say that with my speakers, bi wiring has a notable effect. From what I remember, its not the crossover that accounts for this difference, it has something to do with fields generated by different frequencies over long stretches of wire. The couple inches within the amplifier, that wire just required to get to the output terminals wasnt sufficiently long to make any difference, but over 8 or 10 ft it does.
 
#6
Bi-wiring is very likely hocus-pocus. Speaker wiring left alone for a long period can result in corrosion at the connections and loose connectors. So when you go to bi-wire, the corrosion is gone and all of the connectors are tight, leading you to assume that the improvement is the result of bi-wiring.
 
#7
Perhaps a reduction in the back emf generated by the woofer? Less interaction between crossover elements by their being able to be separated farther apart than usual? But then they would take up more space which the Boss might not like. What would be a more optimal configuration is to have the crossover close to the amp. Crossover likes it better. Just ask it. You can hear a difference even with cheap wire. Whether the difference sounds good or bad depends on the system and implementation. I have found it sounds clearer. Never hurts to try it for the heck of it.
 
#8
#11
No doubt in my mind bi-wiring makes a difference.
For me, it was most noticeable in the midrange/crossover region.

I did numerous tests years ago on more than one system, with another person present, and we both heard similar differences on both systems.
It seems to make bigger differences on longer runs too.

Since my speakers are diy, to convert them, I simply opened them up and separated the woofer and tweeter crossover sections and mounted them in either side of the box (overkill I know, but why not?) and connected them to seperate sets of terminal posts.

Re the opening post: My thinking is, (happy to be proven wrong) although as you mentioned the full range of frequencies travel down both wires, because of the passive crossovers there is only current/power draw at their relative frequency ranges, so each wire still does 'less' work.
I think this sort of was what the second poster was saying too?
As I said though, happy to be proven wrong on this one. 🙂

But there is definitely an audible difference.
 
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#12
I remember a friend of mine also made the same statement, that bi-wiring sounds a lot better than using the jumpers. When i visited him and tested his claims they were indeed true. After investigating into the matter we found out what was really going on. In single wire mode the wires were connected to the low pass filter using the screw. The jumpers were tightened with the exact same screw as the cable, so they did not make a good contact because of the cable, naturally when you connect wires to both filters this problem goes away.
 
#13
Bi wiring does nothing. Those that claim they do need to do a better job at testing to determine what they did in detail. Like stated above,bad connections due to corrosion could be one cause.Also the simple expectation bias. Have a friend swap out the connections back and forth unsighted and unknown to yourself and see if you can pick out which is which.🙂
 
#14
can I try and summerise some of the points just to see if I have the right idea or not. I'm trying to decide if it is worth making my speaker project biwireable or not.

In a single wired system. the signal passess through the speaker cable until it is split to the cross overs where high frequency is filtered out to the woofer and low frequency is filtered out to the tweeter.

In a biwired system it's exactly the same except the point where the circuit splits to send the signal to the woofer or tweeter happens at the amp end of the speaker cables.

The important part of this is that there is no feature in the circuit only sending high or low frequencies to the tweeter or woofer, seperating the signal... instead it is being blocked from where it isn't wanted. so theoretically if the speaker cable and connections are 100% perfect then biwiring and single wiring will sound exactly the same. So the advantage of biwiring then is that it is more forgiving on lower quality or guage cables. Because if you biwire the signal has twice as much cable to travel down to make it's way to the amp. If it is single wired then the signal squeezes down one wire until it is split up in the speaker. So people who can hear a difference by biwiring maybe hearing this due to freeing the signal up traveling along their cable rather than whats happening in the crossover.

Either use thicker higher quality speaker cable or biwire with regular stuff.

Please be aware I am not an expert, I am begginer trying to get a grasp of whats being said... I'm sure I'll be corrected if I've got the wrong idea.
 
#15
Please note that if you have extra channels on your amp then you may be able to bi-amp speakers if they have seperate terminals for bass and treble. This is where each terminal is connected to a different channel on the amp.

This is electrically quite different, and likely to be better than bi-wiring (having two wires connected to the same channel on the amp). I have done this with an Arcam AVR-300, and I perceived a great improvement, but I have not tried getting a friend to help with blind testing it.
 
#18
Here is a simulation of a bi-wired vs single wired 2nd order crossover. The difference is due to the effects of cable impedance. In both cases the cable impedance is exaggerated at 1 ohm for the position and 1 ohm for the negative sides.

An externally hosted image should be here but it was not working when we last tested it.


Now make the cable impedance 0.1 ohms and what do you think the difference will be? Audible?
 
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