No one actually knows how to lculate what speaker cable they need

Methinks he doesn’t know what bi wire is. A myth is as good as a mile. 

I may be mistaken here, but isn’t the net effect of this and bi-wiring the same? My understanding is that bi-wiring
connects one pair of terminals at the amp end along four lengths of wire, connecting to four terminals at the speaker end. Given that both pairs of cable carry full range signals, what you’re effectively doing is increasing the gauge of the cable that’s delivering the signal to the speaker.

And that’s the same principle we’re talking about in this thread.

What b4icu is doing is setting a lower limit on the gauge of the cable that connects the speakers and amp. He’s been saying all along (I think) that it doesn’t matter whether you use one cable, two, or 10, as long as the combined gauge meets that lower limit, you’ll get the improvement.

Now, whether you agree that the DF of an amp is in any way an indicator of what cable you need, or whether b4icu has a formula that works, or even whether there’s a theoretical maximum gauge of cable for an amps DF (why not just go 8/0 and be done with it), is a separate point. As are cable weaves and twists, insulation material, termination solder material, etc.

My point is, like for like, bi-wired 12 awg should be the same as a single cable of 9 awg, so why wouldn’t upping the gauge to 0 have a bigger difference? Or is there some benefit to carrying the same full range signal along two cables?

Happy to be schooled, but I’m also going to try this idea out.

conradnash10-14-2018 10:27am

I may be mistaken here, but isn’t the net effect of this and bi-wiring the same? My understanding is that bi-amping connects one pair of terminals at the amp end along four lengths of wire, connecting to four terminals at the speaker end ...

Yes, you are mistaken. In a two-channel system, biamping uses two stereo amplifiers (or four monoblocs), with a separate amplifier channel used for each LF and HF section of each speaker system.

Ideally, this is done using an active crossover between the preamp and the amplifiers, so that each amp "sees" only the frequencies it will be driving.

I understand. I mistyped. I mean bi-wiring. I’ll edit my message so it’s consistent. 

Bi Wire

The base to the approach came from Bi-Amp (or Tri Amp.), in which the crossover was bypassed. An electronic cross is placed between the Pre and the powers. Each band that drives each of the units of that speaker is getting its specific audio band, its specific amplification and speaker cables. This is better than the ordinary method, because the speaker's crossover contributes some distortion that is avoided by the Bi/Tri amp.

Some manufacturers came up with an idea (not really works in real!) that if it's not Bi amp, it can be Bi-wired. The claim was, that the low Fr. Currents related to the woofer, won't affect the currents of the high Fr of the midrange and the tweeter. The Bi-wire became over night popular and most speaker makers provided two sets of binding posts and some flat jumpers.

This approach was good, if such a speaker owner would like to go Bi-amp without the need in some cases to replace the speaker or drill holes for more binding posts. The internal cross should be removed and bypassed in most cases.

If a simulation is run on a computer SW called "Spice" (most common for analog HW simulation with design) and the two options: Bi wire and single wire) are run, with identical speaker wires (represented by resistors of small value), the result of a single wire is better than a bi-wire.

To understand the why, a Bi-wire approach separates the current loops. So the low Fr. Loop, that drives most of the current, by nature of the audio band behavior, has only 1/2 of the cross section available, vs. one single thicker wire. The high Fr. Loop has the same cross section available, even it does not need that much. So you get one cable that is not really been fully used and one that is under sized for the requirement.

Digging deeper, for the Amp. it is the same.

So is for the speaker.

A wire can pass all frequencies as long thier total cuerrent does not exced the wires capabity. We most likely far from that in Audio.

You just have a less good speaker cable with the bi-wire. I would like to believe that we are gathered here to improve that part in our system.