Biwired-Dunlavy V- Bass reduced why?

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.

Shadorne, The connection are correct. Let me dwell on this a little longer.

May be it is the new cables with Vs. Or may be lack of complete distortion at low freq coupled with increased transparancy ( very apparent using same old cables with IVs) percieved sound to have lower bass.

Or may be I made mistake in measurements or reducing the data. I do trust Mr Dunlavy's claim. My old cables are Dunlavy DAL Z8s and have kept it all these years.... Isn't this hobby fun... er pain in unowatt sometimes?

Here's a real dumb question - have you moved your speakers or your listening position, or both? If you have that could well be your problem. FWIW.

Nope!!

Mistery solved!!

Well, Biwiring does NOT reduce bass db but only quality. with my IV's with my old cables, I was comparing uncorrected Ratshack meter values to my previously measured single wire corrected ref. I did not realize untill test I did just 20 minutes ago from scratch: with single wire and with biwire. Both numbers are exactly the same.

Downstairs with V's it must be the new cables!!

Sorry, did not mean to mislead anyone!!! Thanks to thoes who answered to the thread.