Speaker bi-wiring

[pipis2010]

Hi guys,

 

I recently bi-wired my Energy RC-30 floorstanders and was quite happy with the end result. I used a QED silver anniversary XT for the highs and a JW Audio (great boutique brand btw) copper cable for the lows - the result was very impressive, although my speakers are really entry level.

 

So, I was wondering what do you use when bi-wiring? Do you use the exact same cable, or different models of the same manufacturer, or different manufacturers, or perhaps you also prefer a combination of copper/silver or just one type? I am curious to know!

 

 

Sent from my iPhone using Computer Audiophile mobile app

[XP9433]

I recently bi-wired my Energy RC-30 floorstanders and was quite happy with the end result. I used a QED silver anniversary XT for the highs and a JW Audio (great boutique brand btw) copper cable for the lows - the result was very impressive, although my speakers are really entry level.

 

So, I was wondering what do you use when bi-wiring? Do you use the exact same cable, or different models of the same manufacturer, or different manufacturers, or perhaps you also prefer a combination of copper/silver or just one type? I am curious to know!

 

You have experimented with mixed cables with good results, so you really have answered that question yourself. I guess that the tweeter crossover point on the RC30 is 2.5 - 3.0 kHz, so your JW Audio cables are driving the two midrange/woofer drivers in a 1.5 configuration (one midrange/woofer up to about 300Hz) up to the tweeter crossover point. Just about all of the music (bass midrange and lower treble) are being handled by your JW Audio cables, so in my opinion that is where the best cable is required if you have to make such a choice for $ reasons. The tweeter cable only needs to handle mid to high treble well.

 

Does that help?

 

Cheers

Frank

[dookdull]

The tweeter cable only needs to handle mid to high treble well

[wgscott]

I bi-wired my speakers because they provided that option and I did not think carefully about how the circuit is topologically identical to that having a single pair of speaker wires and bridges between the binding posts. Then I passively bi-amped, which also makes next to no difference. The proper way to do this is with active crossovers, and removal of the passive ones. I haven't managed to get the balls to dig them out of my speakers.

 

Since bi-wiring makes little to no difference, the different brands of speaker wires are unlikely to as well.

[Sam Lord]

The advantage of biwiring increases directly with cable length and inversely with cable conductance and with amp output impedance. So with ultra-low-z amps like Hypex Class D, it usually makes great sense. For tube amps, not very much. Similar relationships exist for biamping.

[mansr]

I bi-wired my speakers because they provided that option and I did not think carefully about how the circuit is topologically identical to that having a single pair of speaker wires and bridges between the binding posts. Then I passively bi-amped, which also makes next to no difference. The proper way to do this is with active crossovers, and removal of the passive ones. I haven't managed to get the balls to dig them out of my speakers.

 

Since bi-wiring makes little to no difference, the different brands of speaker wires are unlikely to as well.

 

Speakers and camera lenses are pretty much the only things I don't open. Way too easy to screw up, and I already know what they look like from taking apart damaged ones.

[mansr]

The advantage of biwiring increases directly with cable length and inversely with cable conductance and with amp output impedance. So with ultra-low-z amps like Hypex Class D, it usually makes great sense. For tube amps, not very much. Similar relationships exist for biamping.

 

Can't you just use a thicker wire for the same benefit?

[wgscott]

So with ultra-low-z amps like Hypex Class D, it usually makes great sense. .

 

I knew I had a good reason. I just didn't know what it was.

[CR250]

I bi-wired my speakers because they provided that option and I did not think carefully about how the circuit is topologically identical to that having a single pair of speaker wires and bridges between the binding posts. Then I passively bi-amped, which also makes next to no difference. The proper way to do this is with active crossovers, and removal of the passive ones. I haven't managed to get the balls to dig them out of my speakers.

 

Since bi-wiring makes little to no difference, the different brands of speaker wires are unlikely to as well.

 

 

Maybe other people with different systems get different results?

[Sam Lord]

I did not think carefully about how the circuit is topologically identical to that having a single pair of speaker wires and bridges between the binding posts.

Can't you just use a thicker wire for the same benefit?

 

No, and also the advantage of placing a thicker wire anywhere in the speaker circuit needs to be balanced against its reactance and other qualities. When you bi-wire you are increasing the series conductance (=decreasing the series resistance) as well as increasing inductance seen by the amp. But the biwiring advantage comes with the effect of one driver on the other driver. In normal wiring you have two inductively coupled legs feeding all the drivers via a passive crossover, picture the circuit as an "I" with the speaker drivers with crossovers together at the top and the amp output at bottom. In bi-wiring the circuit forms a "V" with the amp at the bottom.

 

In both cases the amp's low impedance drives the current through both the speaker wires, crossover, and drivers. A reasonable model of the equivalent circuits account for the impedance of the speaker wire. In the bi-wired circuit the amp is an AC generator but so is each separately-wired driver, each generates distortion. But it's critical to understand that the amp usually has much lower series (output) impedance than each driver with its crossover. The V-shape illustrates how the signal *generated* from each driver has less amplitude in bi-wiring vs. normal wiring.

 

Why? Each leg of the "V" dissipates the output of the generated distortion from one driver to the other. To determine how much you measure distortion signal of each driver (not a simple chore), then apply Ohm's Law to every point where a voltage drop occurs. Those drops *must* include the output Z of the amp as well as the voltage drops of the speaker wires. It's simplest to model the whole thing resistively, it gives you the energy dissipation you want.

 

In simple terms, the path of distortion from one driver to the other with bi-wiring is impeded more than with normal wiring. I asked Bruno Putzeys about bi-wiring vs. bi-amping of Hypex Class D amps, which have output Z typically under 2 mOhm. He said that bi-wiring gets you very close to bi-amping performance, and is certainly worthwhile precisely because of that extremely low output impedance.