Biwired-Dunlavy V- Bass reduced why?

Nilthepill,

What are you using to drive the Dunlavys?

The change from biwiring is equivalent to a few microhenries, a few pico-farads and a few milli-ohms difference compared to single set of regular cables and binding post jumpers being in the circuit. Given typical speaker X-over networks we are talking differences of less than 1% in equivalent circuits.

To most SS amplifiers this should be no sweat. Such a small difference in X-over might affect a narrow range of frequencies at the xover but why such a big difference in bass, as you report?

Perhaps something else is going on that you have not accounted for...some kind of resonance or ringing between bass driver and amplifier that is tempered with this small change?

(Further food for thought; John Dunlavy was outspoken that he did not believe in large audihble differences.)

The Classe CA-400 with low output impedance/high damping factor (over 100 I would expect) should have no problem. It should sound great with either of your configurations.

It should not make a huge difference as you report (I trust Dunlavy's belief on this matter which is why I am just as puzzled as you are.)

As Herman suggested phase....is it possible somehow that you are wiring the woofers in opposite phase when switching to the biwired configuration?

If you suspect this then try reversing one wire pair to one of the speaker woofer bindposts (reverse only at one end and only on one speaker). See if teh bass comes in more strongly.

You have outstanding speakers and an oustanding amplifier...it was a mystery indeed that this high quality equipment should be so affected by a change of cable. Well designed equipment should be robust and tolerant of such slight changes as the differense from a cable.