"Jim Lesurf" wrote in message

In article , Bob
Latham wrote:
In article , Eiron
wrote:
Dave xxxx wrote:
On another forum a chap says, he has been told, its ok
to use a Quad power amp (140 watts) with a Quad 405
(100 watts) with the same pre amplifier.


The idea being the 606 powers the bass and the 405 the
tweeters.

Speakers being used Spendor s5e

Will this work ?

Quite pointless, as Serge said.

You are both correct from a simple electrical point of
view it is quite pointless. However, I might point out
that rightly or wrongly, probably a substantial majority
of people with an interest in Hi-Fi would say that
Bi-amped systems sound better

If bi-amped means active crossover, multiple amplifiers, multiple drivers,
then yes. That's a working technology that is widely used. It is widely used
in pro audio. It's even used in boom-boxes.

Where have you seen any figures to support the assertion
that the "majority" would say this? And would it mean
more than, "The magazines keep saying it does"? :-)

I'd like to see a reference to an article in an audio ragazine with
meaninful circultation about an actual high end product that bi-amps without
an active product. For example, has Stereophile or HFN ever reviewed a
biamped speaker with no active crossover?

and indeed to be "pointless" the amplifiers would have
to suffer zero load issues.

I know, you think the majority are fools - fair enough.

Not so much fools as poorly informed.

I can't speak for either Dave or Eiron. However I don't
think those who have the above belief are "fools".

Ironically, there's an argument that says that putting a normal woofer in
parallel with a highly reactive tweeter through a passive crossover makes
the reactive tweeter an easier load to drive. The signal through the woofer
drives the power amp output stage up its load line where the out-of-phase
current for the tweeters is coming from output transistors that are already
partially saturated from driving the woofer. The voltage across the output
transistors and the power dissipation in the output stage is therefore
reduced.

Firstly, there are circumstances where bi-amping can
change the results for simple engineering reasons. This
thread threw up an example. The amps have different
gains, thus - unless corrected - altering the frequency
response of the system. The result being an expensive and
inflexible 'tone control'.

Agreed. Anyboydy who assigns the 405 to the woofer and the 606 to the
tweeter gets to enjoy brighter treble and a little uptick in the midrange.
"Brighter is better", anyone? ;-)

It's just an expensive, non-adjustable equalizer.

Secondly, people can easily believe all kinds of things
if they base their ideas on what magazines tell them,
and/or 'listening tests' that aren't carried out in a way
that might lead to a reliable result.

In this case, an audible difference is likely. And, if the listener doesn't
agree with Spendor's speaker voicing, then they will perceive an
improvement.

Trivially easy to
mislead youself. No need to be a "fool". Just someone who
accepts what magazines ("experts") say and don't have any
idea how many ways there are for a listening test to give
a misleading or worthless result.

Interesting how many people pooh-pooh equalizers, but rush to accept an
badly-designed "Bi-amp" equalizer implmented by what might be the most
expensive and non-adjustable means possible.