Quad 606 with a Quad 405
 

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 ?

Said Quad told him they have the same "gain"


ta in advance

Dave

Quad 606 with a Quad 405
 

"Dave xxxx" wrote in message
k...
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 ?

Said Quad told him they have the same "gain"


ta in advance

Dave


As they have the same gain, then they will put out the same power into the
same load. The 405, being a lower powered amplifier, will clip first, so if
you use passive biamping, that is, using the passive crossover in the
Spendors, the total output level will be limited by the clipping of the 405,
so you would have the same result as if you had two 405s. If you use an
active crossover between the pre-amp and the 'speaker, then you can take
advantage of the higher power of the 606 in the bass, and the lower power of
the 405 should be unimportant for the treble.

This shows the pointlessness of passive biamping, and the total power
available is the same as if you had used a single power amplifier, and you
only get the benefit of separate bass and treble amplification if you go
fully active with an electronic crossover.


Nevertheless, the advice you received from QUAD is correct.

S.

--
http://audiopages.googlepages.com

Quad 606 with a Quad 405
 

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.

To get any benefit you need to rip out the passive crossover
and put one of these between the preamp and the power amps:
http://www.behringer.com/DCX2496/index.cfm?lang=eng

--
Eiron.

Quad 606 with a Quad 405
 

"Dave xxxx" wrote in message
k
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.

This story comes around every once in a while - different details, same
basic old wife's tale.

Speakers being used Spendor s5e

Will this work ?

Yes, but without some engineering, it is pretty pointless.

Said Quad told him they have the same "gain"

Not true.

http://www.hifiengine.com/download_c...p?quad_606.pdf says the
606 puts out 140 watts with 0.5 volt input.

http://www.hifiengine.com/download_c...5_brochure.pdf
says the 405 puts out 100 watts with 0.5 volt input.

http://stereophile.com/floorloudspea...or/index4.html

Shows a fairly typical impedance curve. Note that the impedance of this
speaker in the tweeter's range is 10 ohms, which means that it is
providing only a small fraction of the total load on the power amp that is
driving it.

Quad 606 with a Quad 405
 

"Bob Latham" wrote in message


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

But this isn't really bi-amping. There are still passive crossovers, and
both amplifiers have to amplify the full signal.

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

Note that the impedance curve of this speaker shows that the tweeter
provides only a small fraction of the load on the power amplifier.

Quad 606 with a Quad 405
 

"Dave xxxx"

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.

Said Quad told him they have the same "gain"



** Quad is a company, not a person.

What some staffer allegedly said on the phone to some fool who was incapable
of comprehending his own question, let alone the reply he got, is purest
******** !!


The 405 and the 606 have the same nominal " input sensitivity" of 500mV.

But NOT the same gain !!

The 606 has just on 2 dB more gain.



........ Phil

Quad 606 with a Quad 405
 

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

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"? :-)


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

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

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

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'.

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. 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.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

Quad 606 with a Quad 405
 

"Bob Latham" wrote in message

In article ,
Arny Krueger wrote:
"Bob Latham" wrote in message


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

But this isn't really bi-amping. There are still passive
crossovers, and both amplifiers have to amplify the full
signal.

Its not "active" certainly but it is what most would mean
by bi-amped.

Who is this "most"?

Most audio fanatics?

Bi-amped has traditionally meant, and means in most audio circles to this
day, active crossover, two power amps, two-way speaker system.

That a few naive audiophiles have been snookered into buying two amps to a
job that one amp can do as well, is an aberration.

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

Note that the impedance curve of this speaker shows that
the tweeter provides only a small fraction of the load
on the power amplifier.

Oh agreed completely. I suspect the pro bi-amp argument
would say that the heavy current load of the bass driver
is detrimental to the performance of the
amplifier/cable/tweeter performance.

That may sell on the salon sales floor, targeted at naive audiophiles that
have money burning a hole in their pockets.

Look a the vast majority of commercial products, not the world of sleezy
deals involving audio imbeciles. It is very hard to find commercial
bi-amped speakers that don't also have an active crossover.

Quad 606 with a Quad 405
 

"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.

Quad 606 with a Quad 405
 

"MiNe 109" wrote in message


In article ,

"Arny Krueger" wrote:

Bi-amped has traditionally meant, and means in most
audio circles to this day, active crossover, two power
amps, two-way speaker system.

Hence the term 'passive bi-amping' to distinguish it from
your definition.

There's a whole forest of made-up terms out there for this sort of
weirdness:

vertical bi-amp

horizontal bi-amp

come to mind.

A possible case for the passive method is as an
intermediate step for one who wishes to complete the
active system later.

Almost everything is possible in the world of imagination. Doesn't make many
of them anything like a good idea.

OTOH, traditional biamping is becoming a trend, as a delivered complete
engineered speaker/amp system, not a random collection of parts thrown
together by clueless audiophile dupes and shyster sales hacks.

Quad 606 with a Quad 405
 

"MiNe 109" wrote in message

In article ,
"Arny Krueger" wrote:

"MiNe 109" wrote in message


In article
,

"Arny Krueger" wrote:

Bi-amped has traditionally meant, and means in most
audio circles to this day, active crossover, two power
amps, two-way speaker system.

Hence the term 'passive bi-amping' to distinguish it
from your definition.

There's a whole forest of made-up terms out there for
this sort of weirdness:

vertical bi-amp

horizontal bi-amp

come to mind.

Those are different configurations of passive bi-amping.

A possible case for the passive method is as an
intermediate step for one who wishes to complete the
active system later.

Almost everything is possible in the world of
imagination. Doesn't make many of them anything like a
good idea.

This is one of the good ones.

For the sales guy!

Here's a bad idea:
off-the-shelf electronic crossover to replace a specific
passive crossover.

That might not be any worse than using two power amps with mismatched gains,
which is what the combination that OP mentioned had. Yes, the OP had been
told a tall tale about matched gains, but the relevant facts told a
different story. The amps did not have matched gains. There was more than
enough gain difference to change the basic sound of the Spendors.

OTOH, traditional biamping is becoming a trend, as a
delivered complete engineered speaker/amp system, not a
random collection of parts thrown together by clueless
audiophile dupes and shyster sales hacks.

How are amps from the same maker said to have the same
gain a "random collection of parts"?

You're apparently not following the whole thread, Stephen. Yes, the OP said
that he was told that he had two amps from the same maker that had the same
gain. When we looked at the relevant facts, we found that someone had been
telling him audio fairy stories. The amps don't have matched gain, no matter
what he was told.

Quad 606 with a Quad 405
 

In article , Arny
Krueger
wrote:
"Jim Lesurf" wrote in message

In article , Bob Latham
wrote:

[snip]

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?

I have a vague feeling that HFN may have once reviewed the 'systems' that
some people put together. In general, of course, that won't be anything
that was intended by either the speaker manufacturer or the amp
manufacturer.

However IIRC back in the 1980's there was a UK fad for using multiple Naim
power amps to 'bi amp' the Linn Isobarik. Not sure if Naim or Linn pushed
the idea, but some dealers and 'subjective reviewers' did at the time.

Personally, I disliked both the Isobarik, and the Naim amps. So for me the
main benefit was that it piled the items I didn't want somewhere away from
where I had to encounter them. :-)

FWIW The Isobarik had an impedance that went south at LF, and the Naim
amps of the period had an output 0.22 Ohm series resistor and limited
current capability. So the Naim/Isobarik system did have a different
response to using an amp with low output impedance and decent current
capability. However I tended to make the choice here that wasn't the one
touted in magazines at the time. :-)

At the time Linn dealers used to insist that 'stereo image' was a myth.
Perhaps because you couldn't get one when using Isobariks. ;-

The most dramatic change I ever heard was in a shop when the removed the
Isobariks and tried Quad 63's. From awful to excellent. They shop droids
hated the Quads. But then they were unable to hear that one of the tweeters
in one of the Isobariks was busted... :-)

[snip]

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.

A few months ago there was someone putting a flawed argument forwards on
the 'audioholics' website in a thread about bi-wiring.

The wording of the claims 'evolved' as it was challenged. However it tended
to be based on saying there was a form of 'intermodulation' occurring in
conventional wiring that biwiring removed.

Mysterious consequences were described such as components in the spectrum
that an FFT could not show. Doubters were treated as being unable to grasp
the reality as they lacked the scientific insight of the idea's presenter.
;-

The argument used was incorrect, or at least inappropriate, and thus lead
to an wrong conclusion. I did an analysis and it was another example of how
a simple misconception can mislead, but a detailed analysis takes ages to
show what a good engineer would have thought in the first place. i.e. No
such problem, so no need for biwiring as a 'solution'. No real problem
with the FFT, either. Nor indeed with mudane ideas like linear
superposition, etc. :-)

Shame if anyone though they were hearing what was claimed since the claimed
theory didn't stand up to either measurement or careful analysis based on
the physics involved according to the claimant's own descriptions.

None of which stopped the claimant from continuing to push his idea.

I wonder if any of that appeared in any USA printed mags?... Didn't appear
here in print so far as I know.

[snip]

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.

IIRC the use of biamping, biwiring, etc, all tended to only come into vogue
*after* the gurus decided that 'tone controls are baaaad' and makers saved
cash by stopped including them. No problem for them if the result was that
people bought more amplifiers. :-)

Personally I still like tone controls and balance controls to be avilable.
Although I appreciate them being designed to work well, and to be bypassed
if preferred. Much cheaper and more flexible than biamping IMHO.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

Quad 606 with a Quad 405
 

MiNe 109 wrote:

Here's a bad idea: off-the-shelf
electronic crossover to replace a specific passive crossover.

The 'off-the-shelf' crossover I mentioned is accurate, high-order
and has adjustable delay. How can that be worse than a passive one?

--
Eiron.

Quad 606 with a Quad 405
 

"MiNe 109" wrote in message

In article ,
"Arny Krueger" wrote:

"MiNe 109" wrote in message

In article
, "Arny
Krueger" wrote:

"MiNe 109" wrote in
message


In article
,

"Arny Krueger" wrote:

Bi-amped has traditionally meant, and means in most
audio circles to this day, active crossover, two
power amps, two-way speaker system.

Hence the term 'passive bi-amping' to distinguish it
from your definition.

There's a whole forest of made-up terms out there for
this sort of weirdness:

vertical bi-amp

horizontal bi-amp

come to mind.

Those are different configurations of passive bi-amping.

A possible case for the passive method is as an
intermediate step for one who wishes to complete the
active system later.

Almost everything is possible in the world of
imagination. Doesn't make many of them anything like a
good idea.

This is one of the good ones.

For the sales guy!

The sales guy has to wait for the eventual purchase of
the active crossover.

Here's a bad idea:
off-the-shelf electronic crossover to replace a specific
passive crossover.

That might not be any worse than using two power amps
with mismatched gains, which is what the combination
that OP mentioned had. Yes, the OP had been told a tall
tale about matched gains, but the relevant facts told a
different story. The amps did not have matched gains.
There was more than enough gain difference to change the
basic sound of the Spendors.

That's too bad for him.

OTOH, traditional biamping is becoming a trend, as a
delivered complete engineered speaker/amp system, not a
random collection of parts thrown together by clueless
audiophile dupes and shyster sales hacks.

How are amps from the same maker said to have the same
gain a "random collection of parts"?

You're apparently not following the whole thread,
Stephen. Yes, the OP said that he was told that he had
two amps from the same maker that had the same gain.
When we looked at the relevant facts, we found that
someone had been telling him audio fairy stories. The
amps don't have matched gain, no matter what he was
told.

Perhaps you could suggest a way of matching gains.

In this case, the most sensible approach is to use just one amplifier.

Quad 606 with a Quad 405
 

"Eiron" wrote in message

MiNe 109 wrote:

Here's a bad idea: off-the-shelf
electronic crossover to replace a specific passive
crossover.

The 'off-the-shelf' crossover I mentioned is accurate,
high-order and has adjustable delay. How can that be
worse than a passive one?

A well-designed passive crossover also considers the response of the
drivers, possibly with additional compensating components, crossover points
and and filter Q's shifted to compensate for the drivers.

Quad 606 with a Quad 405
 

"Arny Krueger" wrote in message
...
"Bob Latham" wrote in message

In article ,
Arny Krueger wrote:
"Bob Latham" wrote in message


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

But this isn't really bi-amping. There are still passive
crossovers, and both amplifiers have to amplify the full
signal.

Its not "active" certainly but it is what most would mean
by bi-amped.

Who is this "most"?

Most audio fanatics?

Bi-amped has traditionally meant, and means in most audio circles to this
day, active crossover, two power amps, two-way speaker system.

That a few naive audiophiles have been snookered into buying two amps to a
job that one amp can do as well, is an aberration.


Arny, as this is a UK news group, we normally use UK nomenclature. This side
of the pond, using two amplifiers but retaining the passive crossover is
generally called "bi-amping" whilst using two amplifiers with electronic
crossovers is generally called "active". The former is of no value whilst
the latter provides many benefits.

S.

--
http://audiopages.googlepages.com

Quad 606 with a Quad 405
 

"Arny Krueger" wrote in message
...
"MiNe 109" wrote in message

In article ,
"Arny Krueger" wrote:

"MiNe 109" wrote in message


In article
,

"Arny Krueger" wrote:

Bi-amped has traditionally meant, and means in most
audio circles to this day, active crossover, two power
amps, two-way speaker system.

Hence the term 'passive bi-amping' to distinguish it
from your definition.

There's a whole forest of made-up terms out there for
this sort of weirdness:

vertical bi-amp

horizontal bi-amp

come to mind.

Those are different configurations of passive bi-amping.

A possible case for the passive method is as an
intermediate step for one who wishes to complete the
active system later.

Almost everything is possible in the world of
imagination. Doesn't make many of them anything like a
good idea.

This is one of the good ones.

For the sales guy!

Here's a bad idea:
off-the-shelf electronic crossover to replace a specific
passive crossover.

That might not be any worse than using two power amps with mismatched
gains, which is what the combination that OP mentioned had. Yes, the OP
had been told a tall tale about matched gains, but the relevant facts told
a different story. The amps did not have matched gains. There was more
than enough gain difference to change the basic sound of the Spendors.

OTOH, traditional biamping is becoming a trend, as a
delivered complete engineered speaker/amp system, not a
random collection of parts thrown together by clueless
audiophile dupes and shyster sales hacks.

How are amps from the same maker said to have the same
gain a "random collection of parts"?

You're apparently not following the whole thread, Stephen. Yes, the OP
said that he was told that he had two amps from the same maker that had
the same gain. When we looked at the relevant facts, we found that someone
had been telling him audio fairy stories. The amps don't have matched
gain, no matter what he was told.


The OP was told, apparantly erroneously, by QUAD that the amps had the same
gain. Consequently, they could be used for bi-amping. However, it turns out
that the amps don't have the same gain, but the same sensitivity for full
power, consequently they can't be used for bi-amping unless the more
sensitive (606) is padded down to match the less sensitive (405).

S.


--
http://audiopages.googlepages.com

Quad 606 with a Quad 405
 

"Serge Auckland" wrote in
message
"Arny Krueger" wrote in message
...

Yes, the OP said that he was told that he had
two amps from the same maker that had the same gain.
When we looked at the relevant facts, we found that
someone had been telling him audio fairy stories. The
amps don't have matched gain, no matter what he was
told.

The OP was told, apparantly erroneously, by QUAD that the
amps had the same gain. Consequently, they could be used
for bi-amping. However, it turns out that the amps don't
have the same gain, but the same sensitivity for full
power, consequently they can't be used for bi-amping
unless the more sensitive (606) is padded down to match
the less sensitive (405).

Agreed. What we were possibly seeing here was a stimulus for the creation
apparent support for yet another audio myth - the myth of passive
biamplification. Had the OP fallen for the erroneous advice he received, he
would have probably heard a difference due to the difference in the
amplifier gains.

Fortunately a little fact-checking nipped the potential damage done by the
erroneoua advice in the bud.

Quad 606 with a Quad 405
 

In article ,
MiNe 109 wrote:


Am I the only one who has actually used a multiple amp passive system?
In my case, Linn Kabers, a single LK100 was better than a Majik
integrated, but two LK100s weren't better than a single. Three with an
active crossover were a massive improvement.

A) What steps did you take to check if the frequency response was the same
in every case? e.g. did you ensure the gain levels were the same in each
case?

B) What steps did you take to ensure that your conclusions were based
solely on the actual biamping? e.g. not due to variations in your hearing,
or a slight movement in speaker locations, or a combination of various other
possible variables?

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

Quad 606 with a Quad 405
 

The most dramatic change I ever heard was in a shop when the removed the
Isobariks and tried Quad 63's. From awful to excellent. They shop droids
hated the Quads. But then they were unable to hear that one of the tweeters
in one of the Isobariks was busted... :-)


"Never in the field of domestic audio was so much bull**** dispensed by
so few and believed by so many"

With apologies to Winnie;)...
--
Tony Sayer

Quad 606 with a Quad 405
 

In article ,
tony sayer wrote:
The most dramatic change I ever heard was in a shop when the removed the
Isobariks and tried Quad 63's. From awful to excellent. They shop droids
hated the Quads. But then they were unable to hear that one of the tweeters
in one of the Isobariks was busted... :-)


"Never in the field of domestic audio was so much bull**** dispensed by
so few and believed by so many"

The problem, alas, was that it was a 'key' few people in just the right
places to influence readers of the magazines, and those who innocently
walked into the shops in question. IMHO the results blighted UK domestic
audio for over a decade.

I don't blame those who went into the shops, and bought the gear. Often
they were given no real chance to hear alternatives or make a judgement for
themselves without being led by the magazines and salesdroids. In the case
I had in mind we had to nag the driods until after I'd shown the Isobariks
were damaged to force them to even bring any other speakers (the 63's) into
the room. They did so with bad grace, mumbling comments about how poor the
63's were.

I wonder if they sold the Isobariks to someone without replacing the broken
tweeter...

Remember this was also the days when part of the 'wisdom' was that any
other speakers in the room might 'upset the sound'. Maybe by allowing the
listener to discover how they were being led to buy actually compared with
alternatives. :-)

Curiously, the items in question had carefully controlled 'franchises' with
higher mark up rates. Triumph of marketing over content. Given the
treatment in the magazines, the items 'sold themselves'. The punter walked
into the shop asking to hear that specific setup, heard it, and bought it.
No real comparisons or experimentation.

No doubt this all still goes on in some cases. One of the reasons I got fed
up with the audio biz as a living. I also know of other engineers who left
the field for similar reasons.

Maybe these days I am a gamekeeper turned poacher... :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

Quad 606 with a Quad 405
 

"MiNe 109" wrote in message


You'll notice adding amps didn't make any difference to
me until I added the new crossover.

That is the expected result.

However, that
improvement was such that I wondered if Linn purposely
degraded the passive crossover.

Sighted evaluation with a big delay between before and after. Who knows?

FWIW, Linn claim deeper
measured bass for the active version.

Easily accomplished by throwing some eq into the active crossover. OTOH,
there are so many other opportunities to change midrange frequency response,
system balance, etc.

There's really nothing wrong with a well-designed passive crossover. But
using an active crossover gives the designer more options.

Quad 606 with a Quad 405
 

In article ,
MiNe 109 wrote:
In article , Jim Lesurf
wrote:

In article
,
MiNe 109 wrote:


Am I the only one who has actually used a multiple amp passive
system? In my case, Linn Kabers, a single LK100 was better than a
Majik integrated, but two LK100s weren't better than a single. Three
with an active crossover were a massive improvement.


[snip details of Q and A]

Thanks for the response. Helped to clarify the situation.

I don't assume bi-amping as such was the difference, but the active
crossover I think responsible for the improvement requires separate amps
for each driver. Since one removes the passive crossover to install the
active, no direct comparison is possible.

You'll notice adding amps didn't make any difference to me until I added
the new crossover. However, that improvement was such that I wondered
if Linn purposely degraded the passive crossover. FWIW, Linn claim
deeper measured bass for the active version.

The above seems very plausible as a reason to me. Thanks.

However it makes clear that the comparison you did was quite unlike the
process where someone simply uses two amps instead of one whilst leaving
the 'crossover' networks as were.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

Quad 606 with a Quad 405
 

In article , Arny
Krueger
wrote:
"MiNe 109" wrote in message


You'll notice adding amps didn't make any difference to me until I
added the new crossover.

That is the expected result.

However, that improvement was such that I wondered if Linn purposely
degraded the passive crossover.

Sighted evaluation with a big delay between before and after. Who knows?

FWIW, Linn claim deeper measured bass for the active version.

Easily accomplished by throwing some eq into the active crossover. OTOH,
there are so many other opportunities to change midrange frequency
response, system balance, etc.

There's really nothing wrong with a well-designed passive crossover. But
using an active crossover gives the designer more options.

I don't have any specs to hand on the Kabers. However Linn have in the past
had a habit of producing speakers with quite 'nasty' impedance plots,
dropping well below 4 Ohms in places. They may also have followed Naim's
religious faith in using a 0.22 Ohm output series resistor in the power
amps. Thus making it easy for slight changes in the filtering to alter the
overall response. So what Stephen and yourself have said seem quite
plausible.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

Quad 606 with a Quad 405
 

"Bob Latham" wrote in message
...
In article ,
Serge Auckland wrote:

Arny, as this is a UK news group, we normally use UK nomenclature. This
side of the pond, using two amplifiers but retaining the passive
crossover is generally called "bi-amping" whilst using two amplifiers
with electronic crossovers is generally called "active".

Sounds about right to me.

The former is of no value whilst the latter provides many benefits.

Such overwhelming confidence presumably means you've tried it.


Bob.

--
Bob Latham
Stourbridge, West Midlands

As I grew up in Broadcast, active 'speakers were quite common. I discovered
active 'speakers for home use in the mid '80s and have not had passive
'speakers since. In my view there are several benefits from active
operation:-

1) Not having a passive crossover means no resistive losses in the
inevitable series resistance of inductors in series with bass units, and
with consequently better damping factor, although it is a moot point as to
how much the slightly improved damping factor matters.

2) Crossover frequencies and slopes can be much more accurately and
repeatedly tailored with electronic crossovers, especially if done in DSP
than is possible with passive lumped components.

3) The power output of an active system is additive, as the bass amplifiers
only amplify bass signals, ditto for the treble. Using two 100 watt
amplifiers driving 8 ohm bass and treble units is equivalent to a single 400
watt amplifier driving the same drive units passively crossovered as the *
peak voltages* are additive.

4) As I don't get pleasure from owning lots of boxes, nor playing mix 'n
match with amps etc, an active system having everything in the one box is
domestically more acceptable, and is cheaper as you're not paying for fancy
boxes for the amps, nor have to find the space for them.


I use Meridian 'speakers in my main system and small Genelecs in my second
system, and nothing I've heard recently would make me change.

S.



--
http://audiopages.googlepages.com

Quad 606 with a Quad 405
 

"Jim Lesurf" wrote in message
...
In article ,
tony sayer wrote:
The most dramatic change I ever heard was in a shop when the removed the
Isobariks and tried Quad 63's. From awful to excellent. They shop droids
hated the Quads. But then they were unable to hear that one of the
tweeters
in one of the Isobariks was busted... :-)


"Never in the field of domestic audio was so much bull**** dispensed by
so few and believed by so many"

The problem, alas, was that it was a 'key' few people in just the right
places to influence readers of the magazines, and those who innocently
walked into the shops in question. IMHO the results blighted UK domestic
audio for over a decade.

I don't blame those who went into the shops, and bought the gear. Often
they were given no real chance to hear alternatives or make a judgement
for
themselves without being led by the magazines and salesdroids. In the case
I had in mind we had to nag the driods until after I'd shown the Isobariks
were damaged to force them to even bring any other speakers (the 63's)
into
the room. They did so with bad grace, mumbling comments about how poor the
63's were.

I wonder if they sold the Isobariks to someone without replacing the
broken
tweeter...

Remember this was also the days when part of the 'wisdom' was that any
other speakers in the room might 'upset the sound'. Maybe by allowing the
listener to discover how they were being led to buy actually compared with
alternatives. :-)

Curiously, the items in question had carefully controlled 'franchises'
with
higher mark up rates. Triumph of marketing over content. Given the
treatment in the magazines, the items 'sold themselves'. The punter walked
into the shop asking to hear that specific setup, heard it, and bought it.
No real comparisons or experimentation.

No doubt this all still goes on in some cases. One of the reasons I got
fed
up with the audio biz as a living. I also know of other engineers who left
the field for similar reasons.

Maybe these days I am a gamekeeper turned poacher... :-)

Slainte,

Jim

--
Electronics
http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

When I was involved with consumer audio in the mid '80s, (some may remember
Beechwood Audio in Braintree and Bury St Edmunds) I ran an ad in the April
edition of Hi-Fi News offering single ear demonstrations. This required two
customers, one would listen with their right ear blocked, and the other with
the left. At the end of the piece of music, each listener would tell the
other what they had just heard, thus restoring the stereo experience.

It attests to the spirit of the time that only a few older customers
actually understood the ad for what it was......

Not surprisingly, I returned to the relative sanity of broadcasting shortly
afterwards.

S.

--
http://audiopages.googlepages.com