Freaky speaker experience:

I'll third Rleff.

Regards,
-- Al

Rleff -- Interesting thought, but I wouldn't think so. From the amp's perspective, the speaker load impedance should appear to be the same in both cases, with the VERY slight exceptions that:

-- The total wire resistance and inductance, being greater in the non-biwired configuration, would cause the amp to see a VERY slightly heavier load in the biwired configuration.

-- The amp would see a VERY slightly greater amount of load capacitance in the biwired configuration.

-- The amp would have to deal with a VERY slightly greater amount of back-emf from the woofer section in the biwired configuration, because a VERY slightly greater fraction of it would be absorbed by the high frequency section of the speaker in the non-biwired configuration.

But I would think that all of those differences would be extremely minute, probably not audible at all, and certainly not enough to account for what Cepages seems to be describing. And having the amp deal with woofer back-emf, rather than the mid/tweeter parts of the speaker, normally improves rather than degrades the sound.

In saying these things I'm assuming, of course, that the wires do not have extreme, outlandish values of either resistance, inductance, or capacitance.

Greg said:

he told me that when you bi wire the current of your amp gets divided between the two wires and that only half the current would get to the woofers and half to the highs

He mis-stated that to you. What happens when you biwire is that the low frequency part of the crossover network in the speaker, being in series with the low frequency wires between the speaker and amp, keeps the high frequencies from going through the low frequency wires. And the high frequency part of the crossover network in the speaker, being in series with the high frequency wires between the speaker and amp, keeps the low frequencies from going through the high frequency wires. The result is less interaction between high frequency and low frequency currents, which normally results in a slight benefit. Also, as I noted above, back-emf from the woofer is conducted entirely to the amplifier, rather than some fraction of it being conducted to the mid/high speaker elements.

It's easy to understand how bi-wiring can result in either slight improvement or no improvement, but frankly I have no idea how it could result in significantly worse sound (assuming, again, that the cables have reasonably conventional parameters).

Regards,
-- Al

Hi Greg --

Biamping, as you no doubt realize, is simply a whole different thing compared to either biwiring or single-wiring from a single amp. It has lots of potential benefits, and a search of this and other forums will turn up lots of interesting reading on it. Although, of course, some of the advantages that are often mentioned for biamping only apply to active biamping, where an electronic crossover ahead of the amplifiers replaces the passive crossovers in the speakers. But "passive biamping," which I suspect is what you are doing, has lots of potential advantages, too, which biwiring doesn't provide.

Not sure if you are doing it "vertically" (one amp driving the highs and lows of one speaker, and the other amp driving the highs and lows of the other speaker), or "horizontally" (one amp driving the lows of both speakers; the other amp driving the highs of both speakers). The noted designer Steve McCormack has made the point in posts here that the vertical arrangement is probably preferable because in that arrangement each amplifier sees an identical signal at both of its inputs. That eliminates possible interactions within the amplifier between channels, via power supplies, grounds, and other paths, that can impact the sound when a single amp is handling two different input signals for two different channels.

In either arrangement, biamping reduces or eliminates the possibility of interaction between highs and lows in the amplifier output stages; it provides more total power; it presents each amplifier channel with a less complex load; and there are undoubtedly other advantages which I'm not thinking of right now. As I say, its a whole different thing compared to bi-wiring, which just basically separates the highs and lows so that they travel through different wires.

Best regards,
-- Al

In the second of my posts dated today (July 11) in the other current thread on essentially the same question, I propose the following explanation of what I think is going on here:

Here's a theory I just thought of: You are not really losing bass in the bi-wire configuration; you are just getting better bass damping (meaning tighter, more well-controlled bass), for reasons I'll explain below. That would very conceivably produce the slight measured loss in bass response that you have found (I presume using test tones), and on musical material could very conceivably produce a subjective impression of less bass.

The reason that may be happening is as follows:

In the bi-wire configuration, back-emf from the low frequency drivers is conducted directly (and only) back to the amplifier, which in your case has an extremely good damping factor (i.e., an extremely low output impedance). So the back-emf is absorbed there very effectively.

In the single-wire configuration, some small fraction of the back-emf from the low frequency drivers is conducted through the jumpers into the mid-frequency drivers, where it will not be effectively damped (because the impedance is much higher than at the amplifier output), and, more significantly, WHERE IT WILL PRODUCE SOUND THROUGH THE MID-FREQUENCY DRIVERS, ADDING TO THE SOUND PRODUCED BY THE LOW FREQUENCY DRIVERS.

So you may indeed be getting measurably more bass in the single-wire configuration, but bass which is the result of back-emf effects and is therefore less accurate!

And of course that loss of accuracy in the single-wire configuration (relative to the signal going into the speakers) may be subjectively preferable if it offsets inaccuracies which may exist elsewhere in the system, the room, or the source material.

Regards,
-- Al