Biwired-Dunlavy V- Bass reduced why?

Well, I found out for certain that Biwiring Dunlavy's reduces bass but increases transparency and clarity.

I tried my old cables with upstairs Dunlavy IV whicj also has same cable, same length. So I removed jumpers and biwired and yes indeed biwiring dunlavy does reduce bass v/s using single cable and jumpers.

Downstairs with Dunlavy V the new biwired configuration is still being burned in. But I did my measurments again using test tones and like Bob says it comes and goes. Today it was around 100 hz freq where there was may be 3 db deep. while 50-60 hz was filled up!! Also bass reduced impression is true, the measured bass now is 'flat' compared to ~ 4 db boost that I was used to with my old cables. So may be overall balance measures better which I just have to get used to or get a single new cable and use it with jumpers.

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.)

Shadorne,

I am using Classe CA-400 in stereo mode. I agree this amp can drive any load.

Mr Dunlavy/reviewers in the past claimed/reported no audible change between single and biwiring and that the two terminals are mostly for bi-amping.

As i said in previous posts, I wanted to believe it was new speaker cables with V's, But with IV's using my well broken old cables biwired also showed relative reduction(actually you can think as removal of bass hump)in bass decible.

Is resonance or ringing you describe common phenomena? what are the indications that this happens other than lower bass db?

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?