biwiring speakers?
Paul Elliott
it! I'm sure its been discussed here before, but I cant find the
posts...So let me just state off hand that I dont understand
biwiring..... The wire goes from the + terminal on the amp to the
plus terminal on the speaker...Only it is split between the 2 plus
terminals...Same with the negatives...
But, with the straps in place, doesnt the traditional cable method,
via the strap, supply power to the both connectors at the speaker?
So, what on earth does removing the strap, and running the wire to
the second terminal set accomplish?
It would seem to me that if anything is going on, perhaps its due to
people running a double thickness of cable..Wouldnt the same thing
be accomplished by using traditional means, but using a thicker guage
cable? According to charts I have, 16 gauge cable is more than
sufficient for 8 ohm speakers running only 10 ft away...But that's
another issue....
Intuitively, I dont see how replacing the strap, with a second run of
cable FROM THE SAME AMP CONNECTOR does anything at all beyond what
the default strap is doing in the first place.
Thanks for the response.
Mkuller
>cable FROM THE SAME AMP CONNECTOR does anything at all beyond what
>the default strap is doing in the first place.
Come on, what has logic and intuition got to do with audio? The theory, as I
understand it, is that by removing the strap and running the second pair of
speaker cables from your amp to your speakers, you reduce "back EMF" from your
woofers from interfering with the other drivers. All I can do is suggest you
try it and see if you hear a difference.
Regards,
Mike
Alex Eisenhut
I wonder, does the cable settling time change in this scenario? Do they both
settle at the same time and same rate? Or is there some sort of squared factor at
work, two cables take four times as long to settle?
How about the focus? Those cables better be focused the same or else the tweeter
will sound blurry.
What I'm worried about are confused electrons. You know, the high frequency ones
that end up at the woofer need to turn around somehow and get to the tweeter, and
vice-versa. With the strap, at least, the path was shorter (assuming the strap was
properly broken in and focused) and didn't muddle out the highs too much, but with
that extra cable, who's to say where those electrons are going to go?
Arthur Shapiro
>Call me Luddite...Call me Philistine...Or just call me I dont get
>it! I'm sure its been discussed here before, but I cant find the
>posts...So let me just state off hand that I dont understand
>biwiring....
I'm not going to try and guess why it works, but it made enough of an
improvement on my own speakers that I thought it was worth the
money.
But I'd like to share an experience with single-wiring that might
spark some discussion. It was an audio society meeting at a major
dealership a few months ago. We were listening to Dunlavy SC-IVa
speakers. Amplification was big solid state stuff, and I've drawn a
blank as to whether it was Krell or Roland. The speakers are
biwireable, but in this demonstration they were single-wired with
jumpers.
I happened to be the only one in the room for the better part of an
hour, just one of those things that happens once in a while. I had
been listening to some music that was already playing on a CD,
although it wasn't music of much personal interest. Finally a few
others came into the room.
I put on some very familiar piano music, and let it be noted that I
am extraordinarily sensitive to correct piano tonality. This system
just didn't make it - rather muddy and unremarkable, and nothing that
would leave me anxious to sell my own system. I'd certainly heard
Dunlavy systems sound a lot better.
The speaker cable happened to be connected to the top pair of
terminals, which I'd guess control the midrange and tweeters. As an
experiment, we moved it down to the bottom pair.
The sound was substantially altered for the better. This was the
unanimous opinion, including the dealer's employee who did the
switch. He had some sort of theory about lessening the back EMF
through the crossover, which may or may not be grounded in reality,
but the change was not particularly subtle. Perhaps we should have
gone back and forth a couple times, but the intent of this meeting
wasn't to evaluate speaker cable installation, but simply to enjoy a
particular system. So we left it in the described configuration for
the remainder of the evening. I found the experience puzzling, and
as this was a CD I'd played hundreds of times before, it wasn't - I
assert - a matter of being more accepting of something with the
familiarity of a second playing. Others in the room might not have
had the same advantage.
Anyway, just an anecdotal experience that I thought worthy of
mention.
Art
Richard D Pierce
Mkuller <mku...@aol.com> wrote:
>>Intuitively, I dont see how replacing the strap, with a second run of
>>cable FROM THE SAME AMP CONNECTOR does anything at all beyond what
>>the default strap is doing in the first place.
>
>Come on, what has logic and intuition got to do with audio?
With audio, it has a LOT to do with it. With high-end hype,
mysticism and bunko, it is the very antithesis, agreed.
>The theory, as I
>understand it, is that by removing the strap and running the second pair of
>speaker cables from your amp to your speakers, you reduce "back EMF" from your
>woofers from interfering with the other drivers.
And how does biwiring change this AT ALL? The same set of
drivers is still connected together in essentially the same
manner. Unless the resistance of the leads betwen the amp and
the various drivers is MUCH higher than it actually is, it will
make NO difference.
Further, looking at this as a matter of dealing with
"back-enf" is misleading, resulting in such bogus theories. The
net effect of the so-called "back-emf" is to raise the impedance
of the woofer at resonance and thus reduce the amount of current
flowing in the cable. If anything, the proponents of such a
theory must conclude that the woofer's influence at these
frequencies is REDUCED, not increased as they erroneously claim.
>All I can do is suggest you
>try it and see if you hear a difference.
And that's fine save that the data suggest stroingly that
people will, when trying to listen for difference, detect them
whether or not they are there.
--
| Dick Pierce |
| Professional Audio Development |
| 1-781/826-4953 Voice and FAX |
| DPi...@world.std.com |
Steve Nugent
Analytical studies that I have done show conclusively that speaker
cable bandwidth will be improved with biwiring if the speaker woofer
and tweeter circuits are significantly different in impedance. The
data speaks for itself. Contrary to popular belief, there are those
that have done the analysis and made the measurements. The rest of
you can continue with your heads in the sand!
Steve N.
AudioEnz
> terminals, which I'd guess control the midrange and tweeters. As an
> experiment, we moved it down to the bottom pair.
>
> The sound was substantially altered for the better.
My local Naim dealer hates bi-wiring and refuses to use it, but many of the
speakers in the store come with the double set of terminals.
What the staff there have discovered is that if they put one banana plug in
the tweeter terminal and one in the woofer terminal, that it sounds better
than both in one set.
I haven't tried this and YMMV of course.
Michael Jones
Editor, AudioEnz
--------------------
New Zealand's online hi-fi and home theatre resource
http://www.audioenz.co.nz
Scott Drysdale
wrote:
>I put on some very familiar piano music, and let it be noted that I
>am extraordinarily sensitive to correct piano tonality. This system
>just didn't make it - rather muddy and unremarkable, and nothing that
>would leave me anxious to sell my own system. I'd certainly heard
>Dunlavy systems sound a lot better.
>
>The speaker cable happened to be connected to the top pair of
>terminals, which I'd guess control the midrange and tweeters. As an
>experiment, we moved it down to the bottom pair.
>
>The sound was substantially altered for the better.
is it possible the straps were off (ie, the speakers were previously
used in bi-wire mode but some dummy forgot), and you moved the wires
from the bass (hence muddy) terminals to the mid/tweeter terminals?
--
// scott drysdale // drys...@brandywine.net
// amigas and panheads and guns, oh my!
Richard D Pierce
Steve Nugent <nug...@agora.rdrop.com> wrote:
>Analytical studies that I have done show conclusively that speaker
>cable bandwidth will be improved with biwiring if the speaker woofer
>and tweeter circuits are significantly different in impedance. The
>data speaks for itself.
What data? where is it? Why not present it here, and not just
allude to it?
>Contrary to popular belief, there are those
>that have done the analysis and made the measurements.
What analysis? What measurements?
If you have what constitutes extraordinary data to support
extraordinary claims, why not present them to a peer-reviewed
forum? if you're data holds true, you're in line for a trip to
Scandanavia, lunch with the King of Sweden, a whopping big check
and more fame than anyone in the high-end audio business could
every imagine.
TT
Please take the time to read these 2 excellent articles written in
very basic understandable English and they will answer your questions
better than I can.
http://www.tnt-audio.com/clinica/ffrc_e.html
http://www.tnt-audio.com/clinica/spkcbl_e.html
I have made a couple of sets of the FFRC (Full Frequency Range Cable)
and am very impressed with the results. All I would suggest is that
you try this for yourself and see.
And if you get bored have a look here
http://members.bellatlantic.net/~pcor/Pages/coathangers.html
Regards TT
"Paul Elliott" <pell...@rcn.com> wrote in message
news:9k6jl...@enews2.newsguy.com...
Ed Sheffield
An EE audio nut buddy says a bi-wire arrangement allows much
of the crossover work to be handled at the amps outputs.
This happens because of the different resistance levels demanded by
high frequecies vs lower frequencies.
Employ true "shotgun bi-wiring".
Use identical length runs of the exact same wire. Be careful. Standard
color coding on wire can be very confusing when used in a bi-wire
arrangement.
Look up Vandersteen Audio's web-page for a great look at bi-wiring.
Mr. Vandersteen noticed this effect, apparently by accident, many
years ago.
Remember if the speaker designer allows bi-wiring, he\she actually
intends for you to bi-wire your gear.
To my ears bi-wiring is the next best thing to horizontal bi-amping.
I have Triangle Antals (bi-wireable) and Hales Rev. 3's (not
bi-wireable). The Rev. 3's are simply better. The Antals sound 15-20%
better bi-wired.
The highs improve markedly, and overall clarity is much improved.
Arthur Shapiro
>is it possible the straps were off (ie, the speakers were previously
>used in bi-wire mode but some dummy forgot), and you moved the wires
>from the bass (hence muddy) terminals to the mid/tweeter terminals?
>
In this particular event, the jumpers were correctly installed. Since we
moved from upper to lower, an initial absence of bass would have been
profound had they been forgotten, and quite noticeable on piano. The Dunlavy
products seem to have good bass response, and that failing would have been
obvious.
Note that I'm describing here a noticeable improvement, not the proverbial
"night & day" difference, although not on the fringes of subtlety either.
Art
Alex Eisenhut
>
> Please take the time to read these 2 excellent articles written in
> very basic understandable English and they will answer your questions
> better than I can.
>
> http://www.tnt-audio.com/clinica/ffrc_e.html
> http://www.tnt-audio.com/clinica/spkcbl_e.html
>
> I have made a couple of sets of the FFRC (Full Frequency Range Cable)
> and am very impressed with the results. All I would suggest is that
> you try this for yourself and see.
>
Cool. I use RG-59 coax cable myself as speaker cable. I use pretty much the
same interconnects, I use Radio Shack 'pins' for the amp and I soldered the
speaker end right to the components inside the speaker.
It just seems odd that all interconnect cables are basically an
'unbalanced' configuration, ie the conductors don't see the same impedance
with respect to each other, but speaker cables almost invariably are
'balanced', ie if you reverse the conductors you have the same impedance,
no matter what the amplifier's output looks like. Of course at 20KHz the
cables might need to be 1 km long to see this, but the coax is good cable
and it gets people talking.
Matt Maika
before taking speakers that have the ability to biwire and run them
in series. I know on them the straps are in parallel on my speakers
bass is 8ohms mid/tweeters are 8 ohms so my question as stated can I
put the sections in series giving me 16ohms or will this cause havoc
with the crossover? My reason for doing this is I am in the process
of building a tube amp that is better suited to run at 16ohms any
information on this would be a great help.
Thanks
Matt Maika
Matt_...@hotmail.com
Steve Nugent
impedances. All others that seem to improve are due to
using high-inductance cable. If you use low-inductance cable,
then single-wiring is always better. Maintains phase coherency,
image and dynamics better.
Steve N.
Steve Nugent
the difference in impedance of the two speaker circuits and
the difference in inductance of the two cables. The cable that
was lower inductance was better when connected to the lower
impedance speaker cuicuit.
Steve N.
Steve Nugent
> In article <9k796...@enews1.newsguy.com>,
> Steve Nugent <nug...@agora.rdrop.com> wrote:
> >Analytical studies that I have done show conclusively that speaker
> >cable bandwidth will be improved with biwiring if the speaker woofer
> >and tweeter circuits are significantly different in impedance. The
> >data speaks for itself.
>
> What data? where is it? Why not present it here, and not just
> allude to it?
>
> >Contrary to popular belief, there are those
> >that have done the analysis and made the measurements.
>
> What analysis? What measurements?
See the biwiring study (among others) at:
http://www.empiricalaudio.com/frAudio_FAQ's.html
Steve N.
[quoted text deleted -- deb]
Jose P
better, to others might not.
It has to do with the fact that your speakers are also big microphones. Some
of the speaker vibration also adds distortion to other speakers directly
connected. It really works with only different frequencies. Let's say you
have two midrange drivers they would be driven by a set of wires and the
tweeters by the other set.
Like I said before try if you like then it is the way to go. If not then
don't waste your money buying extra wires and connectors.
FMW
tested has been able to hear the slightest difference between bi wired and
"non-biwired" speakers (assuming the same speakers, of course.) If you ever
happen to be in Indiana, I'd like to test you.
Fred
AudioNow!
http://www.audionow.com
"Ed Sheffield" <edshe...@home.com> wrote in message
news:9k9fjr$dkm$1...@bourbaki.localdomain...
Andrew Haley
biwiring and then very strangely goes on to say
"Some speakers may benefit from bi-wiring, particularly those which
have a tweeter with a higher impedance than the woofer."
The analysis shows a 2.5 degree phase shift at 20kHz and a tweeter
rolloff at 478 KHz, so there's no way to justify that conclusion.
Another way to get a 2.5 degree phase shift at 20kHz is to move a
tweeter by 4 thousandths of an inch.
The page continues from there with some comments about speaker cables
ringing when fed with RF pulses. Well, yes: the moral is not to put
RF signals into speaker cables. As that there are some high bandwidth
audio amplifiers around, this seems like a very good reason to avoid
certain D/A converters that don't have proper anti-imaging filters.
Andrew.
Richard D Pierce
Jose P <bo...@hotmail.com> wrote:
>It's an audio thing. Some people swear by it. To some people might sound
>better, to others might not.
>It has to do with the fact that your speakers are also big microphones.
Well, in fact, it has absolutely NOTHING to do with this,
because, when connected to an amplifier, be it single- or
bi-wired, speakers are NOT big microphones..
>Some
>of the speaker vibration also adds distortion to other speakers directly
>connected. It really works with only different frequencies. Let's say you
>have two midrange drivers they would be driven by a set of wires and the
>tweeters by the other set.
Wrong. Whether the drivers are connected together at the speaker
or connected together at the amplifier, THEY ARE STILL CONNECTED
TOGETHER.
>Like I said before try if you like then it is the way to go. If not then
>don't waste your money buying extra wires and connectors.
And if he tried it, hasn't he ALREADY wasted the money for extra
wires and connectors?
Look, maybe biwiring makes and audible difference, maybe it
doesn't. The claims that it does remain unproven.
But the "theories" and "reasons" given thus far for why it must
are some of the hokeyest techno-bunk seen around these parts in
some time.
Kalman Rubinson
wrote:
>ON the topic of biwireing speakers does anybody know or done this
>before taking speakers that have the ability to biwire and run them
>in series. I know on them the straps are in parallel on my speakers
>bass is 8ohms mid/tweeters are 8 ohms so my question as stated can I
>put the sections in series giving me 16ohms or will this cause havoc
>with the crossover?
Bad idea. It will probably sound terrible. While the impedance may
be doubled to 16ohms, the performance of the crossover and drivers
will be greatly distorted by putting them in series as the standard
crossover topology presumes parallel (or separate) connection. Quite
different series topologies are employed in certain speakers but,
usually, not just for the impedance effects.
Kal
Richard D Pierce
Steve Nugent <nug...@agora.rdrop.com> wrote:
>Richard D Pierce wrote:
>
>> In article <9k796...@enews1.newsguy.com>,
>> Steve Nugent <nug...@agora.rdrop.com> wrote:
>> >Analytical studies that I have done show conclusively that speaker
>> >cable bandwidth will be improved with biwiring if the speaker woofer
>> >and tweeter circuits are significantly different in impedance. The
>> >data speaks for itself.
>>
>> What data? where is it? Why not present it here, and not just
>> allude to it?
>>
>> >Contrary to popular belief, there are those
>> >that have done the analysis and made the measurements.
>>
>> What analysis? What measurements?
>
>See the biwiring study (among others) at:
>http://www.empiricalaudio.com/frAudio_FAQ's.html
While the data is extremely interesting, academically, it has
little or nothing whatsoever to do with audio.
Let's look at the cable response graphs, showing differences
between single and bi-wired examples. There in terms of
frequency response, effectively NO difference whatsoever below
100 kHz. I don't care what fantasy one might want to claim for
the bnandwidth of audio material, it simply is not going to make
any difference.
Let's, instead, look at the phase response: that actually shows
that there is a difference of 2 degree in phase shift at 20 kHz
between the single- and bi-wired examples. That 2 degrees of
phase shift corresponds to a delay difference of 270
nanoseconds. Look at it another way: the difference between
single- and bi-wiring corresponds to moving the speaker 0.0003
inches. Are you SERIOUSLY suggesting that the introduction of a
delay corresponding to a shift in position of a speaker by less
than 1/1000 of an inch is AUDIBLY SIGNIFICANT?
I would thank Mr. Nugent for pointing out this URL, because it
provides what appears to be reasonable data that, in fact,
strongly suggests that bi-wiring DOES NOT make an audible
difference.
It also provides, in some of the other sections, the lengths to
which some will desparetly go, to search for SOME technical
justification for their beliefs. For example, in the next
section on "cable resonance," we see a dramatic graph showing a
very high-Q "resonance" in a cable. Seems pretty damned
impressive and convincing if you just look at the graph. Nice
graph. Pretty curves. Totally unrealistic.
We have to read the text with some care to learn that to obtain
the graphs, we had to excite the cable with a pulse with a rise
time of 35 NANOSECONDS! Now, where on THIS audio earth does the
author propose one finds signals that have rise times that
short? That sort of a rise time implies a signal bandwidth WELL
IN EXCESS OF 1 MHz. How can anyone reasonably make
extrapolations to audibility with this kind of utterly
unrealistic data?
Further, on reading the text, we learn that the conditions for
the simulation are TOTALLY UNREALISTIC: The driving impedance
was 7.7 ohms and THERE IS NO LOAD ATTACHED TO THE END OF THE
CABLE!
Back to bi-wiring, the text goes on to grasp at straws:
"since the amplifier is now located in the middle of the
cable with the tweeter and woofer at each end, it may be
at a cancellation node for standing waves."
Then again, maybe it isn't. Further, if the driving point is at
a node, it will be EASIER to drive the cable to resonance.
A final desparate attempt at technical legitimacy:
"This can possibly cause an amplifier to become non-linear
due to saturation of the transistors or introduce distortion
by increasing the crossover distortion."
Well, if this was so, it would be TRIVIAL to measure, yet there
are NO data to support the assertion.
And, of course, we learn that "www.empiricalaudio.com" makes and
sells cables! Hardly an objective source of information. One
might even hazard to suggest that empiricalaudio has a stake in
the outcome of the purchasing decision of readers of this
information.
No, thank you, the web site does an EXCELLENT job of refuting
the claims about wires, both through the data presented and
indirectly by exposing the bogus "measurements" sometimes made
to support a belief.
JohnDunlavy
Our DAL loudspeakers are equipped with input terminals that permit
bi-wiring - not because we believe that bi-wiring offers any audible
or measurable advantages - but because the lack of such input
terminals might impair sales.
John D.
JohnDunlavy
The bottom and top sets of terminals on the SC-IV/A loudspeakers are
separately connected, respectively, to the woofers and the
mids-tweeters.
This arrangement of input terminals permits the user to bi-amp the
loudspeakers if that is their desire. However, we have never been
able to document the existence of any measurable or audible
improvements from bi-wiring - if suitable guage loudspeaker cables
are used, e.g., 12 AWG (or larger) for runs shorter than about 10 to
12 feet. .
However, what is often called the "expectation effect" influences
most of us to "hear" differences (even when they cannot possibly
exist) - if we "expect" that they might exist.
Indeed, we have even had numerous visitors to our facility describe,
often in elegant terms, the audible differences they believed they
were hearing - even though we pretended to change cables but did not
do so. I have occasionally even thought that I was able to detect
differences when I believed cables were being changed - but were
not.
But the general belief that significant, audible differences exist
"sells" hundreds of thousands of dollars worth of expensive
loudspeaker cables each year with the "expectation" of achieving more
accurate reproduction.
How sad!
But, perhaps even sadder, is the fact that most of the really
expensive audiophile cables are being designed by persons with little
or no relevant technical/engineering backgrounds, education,
experience, etc.
The "audible superiority" of expensive cables is often "demonstrated"
to customers by dealer salespersons that have been "indoctrinated and
trained" by representatives of cable companies that have much to gain
by perpetuating the belief in "near magical" wire properties, etc.
Of course, situations exist where a low-loss, high-capacitance
loudspeaker cable can (and often does) cause an expensive, high
slew-rate power amp (with too much inverse-feedback) to become
unstable and create audible distortion. But this is a case of an
amplifier that is unstable and should not call into question whether
the cable is at fault.
Within a "stable", properly operating, hi-end audiophile system,
using loudspeakers with a minimum input impedance of about 3 Ohms and
a stable power-amp, I have never been able to satisfactorily document
any "truly audible" differences between 12 foot lengths of
high-quality 12 AWG "ZIP Cord" and equal lengths of the most
expensive loudspeaker cables currently being marketed. (Neither have
experienced audiophile visitors to our well-equipped, main,
audiophile listening room.)
Further, all of the advertisements regarding how audible distorion is
often caused by electrons "jumping between strands" of cable
conductors is simply pure baloney. Such statements are made by
persons who are unaware that electrical signals are propagated along
the conductors of a cable, at nearly light speed (186,000 miles per
sec.), by an electromagnetic field surrounding the conductors - not
by electrons within the conductors. (Ask any professor of E.E. or
physics at a good university.)
Anyway - nuf sed!
John D.
George Robertson
> Well, in fact, it has absolutely NOTHING to do with this,
> because, when connected to an amplifier, be it single- or
> bi-wired, speakers are NOT big microphones..
You are actually wrong. The speaker cone does not move in perfect
tandem with the electrical output. It will bounce around, it will
ring after a pulse. Also, sound reflects around the room and
re-excites the cone.
This is partly to do with the mechanical stiffness of the speaker and
enclosure and partly to do with the amplifier. We amp designers used
to talk about a "damping factor." This is how well the amp can "hold
onto the cone." It's related to output impedance. More of a problem
for transformer delivering amps. Also, if the amp has a low output
impedance a "back EMF" will not be a problem.
I'm not sure about bi-wiring. I've got bi-wirable speakers
(celestions) fed from 2 mono amps (quad). The cable length is about 6
inches. Should I really bother.
I've got DAMN good ears, and I've never heard bi-wiring make a
difference. I really haven't. When I worked at the BBC we used miles
if UTP (yes - unshielded single-strand balanced lines) to bounce
around signals. Sounds pretty good to me.
Like the idea of Co-ax. Nice one. Different.
cheers, george
George Robertson
> >ON the topic of biwireing speakers does anybody know or done this
> >before taking speakers that have the ability to biwire and run them
> >in series. I know on them the straps are in parallel on my speakers
> >bass is 8ohms mid/tweeters are 8 ohms so my question as stated can I
> >put the sections in series giving me 16ohms or will this cause havoc
> >with the crossover?
If you put a tweeter and woofer in series you'll get some mid and, maybe,
some high from the woofer. Turn it up and you'll just get mid. Then you'll
get some smoke.
Richard D Pierce
George Robertson <geo...@owl.co.uk> wrote:
>> Well, in fact, it has absolutely NOTHING to do with this,
>> because, when connected to an amplifier, be it single- or
>> bi-wired, speakers are NOT big microphones..
>
>You are actually wrong. The speaker cone does not move in perfect
>tandem with the electrical output. It will bounce around, it will
>ring after a pulse. Also, sound reflects around the room and
>re-excites the cone.
Well, no it doesn't. First, note the fact that very little of
the total power delivered to a loudspeaker ends up being
radiated as sound: for a direct radiator system, it's one the
order of 1% or less. Second, very little of the total acoutistic
output to the room finds it's way back to the speaker. Now, if
you STILL insist that a speaker acts like a microphone, consider
what the sensitivity ofnmicrophon with the diaphragm mass that
it has, it's effect acoustical-mechnical-electrical source
impedance, no driving a load that is a small fraction of that
source impedance.
ANy such production of "back-emf" MUST manifest itself as a
change in the load impedance presented by the speaker: that's
what the peak at resonance is all about: the "back emf" from a
mechnical resonant loudspeaker is NOT ONE BIT DIFFERENT than the
effect of a resistor/capacitor/inductor parallel resonant
circuit. It's exactly the same thing, and exactly the same
result.
Looking, then, at the impedance: we find that the tiniest
portion of the impedance is the result of the acoustical
radiatiuon imp[edance seen by the drivers: it's roughly
proportional to the efficiency of the system. Thus, even LARGE
changes in the radiation impedance caused by the room will only
manifesrt themselves as TINY changes in the electrical behavior
of the speaker, and room effects DO NOT have LARGE effects on
the speaker's radiation impedance, so the real effects are, at
the very most, miniscule.
To claim that a speaker in any substantive way acts like a
microphone in the loudspeaker-amplifier system behavior is a
ludicrous assertion and constitutes, at its best an
extraordinary claim. Where is your extraordinary evidence to
support such a claim?
On the other hand, I HAVE measured the effects, and they are
simply not as you claim.
>This is partly to do with the mechanical stiffness of the speaker and
>enclosure and partly to do with the amplifier. We amp designers used
>to talk about a "damping factor."
And it's good that you amp designers "used" to talk about it
because it is a nonsense specification. I have, on several
occasions, debunked the notion of damping factor. The
amplifier's output impedance is, except in pathological cases
NOT the dominant contrrolling mechanism for damping
speaker: that is co-opted by the single largest source of loop
impedance in the entire speaker-amplifier system, the DC
resistance of the loudspeaker's voice coil. Unless the output
impedance of the amplifier is substatial compared to that, large
changes in the amplifier output impedance will have almost NO
effect on the damping of the system, despite strdient claims to
the contrary.
> This is how well the amp can "hold
>onto the cone."
No, in fact, damping factor is a measure of how irrelevant the
amplifier is in controlling speaker resonances: the higher the
so-called "damping factr" is, the less the amplifiers
contribnution to total system daping is.
Mark Guidry
the speaker from seeing bass, and the bass section of the speaker
from seeing treble. Thus at a given frequency, with the treble and
bass sections in parallel (either biwired or strapped) the amp sees
something close to the speaker's nominal impedance (of course there
are exceptions, but let's keep this discussion simple). The
crossover effectively prevents the amp from "seeing" the treble part
of the speaker when playing a tone below the crossover frequency.
Conversely the amp doen't "see" the bass section of the speaker when
playing a note above the crossover frequency.
Real speakers are of course more complex, and the crossover sections
overlap due to finite slopes. This is one of the causes of complex
impedance curves!
Anyway, if you think about this simple discussion, it's clear that
putting the bass and treble sections of the speaker in series will
fail. In an ideal speaker you'd get no output. In a real speaker
you'd get some signal around the crossover frequency but no real bass
or treble.
You need a speaker designed for 16 ohm impedance.
GRL
My next set of higher-end will speakers will be Dunlavy's. No question.
- GRL
"JohnDunlavy" <johnd...@aol.com> wrote in message
news:9kegq...@enews2.newsguy.com...
Ernst Raedecker
>15% to 20%. Wow. You hear very well. Neither I nor anybody else I've ever
>tested has been able to hear the slightest difference between bi wired and
>"non-biwired" speakers (assuming the same speakers, of course.) If you ever
>happen to be in Indiana, I'd like to test you.
>Fred
>AudioNow!
>http://www.audionow.com
Well, maybe it's time that we count in some factors that could make a
difference as regards bi-wiring.
For one, it depends on the filtering circuit used in the speaker. One
filter could be more sensitive to bi-wiring than another due to the
way it is designed.
Secondly, if you use single wire, the connectors for the highs and the
lows at the speaker must be connected someway. Many times this is done
with a rather cheap pin of some sort. So, instead of bi-wiring, you
could try and test the effect of using a short piece of your speaker
cable to connect the connectors instead of the standard pin. Then,
later, compare this sound to that of bi-wiring.
Thirdly, it could depend on the sensitivity of the amplifier to the
speaker load in some way.
I have tried bi-wiring at home with 3 speakers: the Monitor Audio 20
SE (the grey one, special edition), the Diapason Adamantes (?, forgot
the exact name) and the Audio Note E-SPa's that I have currently at
home.
My personal listening results:
1) Monitor Audio.
For once I could agree with Dick Pierce in not hearing much of a
difference. Although many people having Monitor Audio's state they
like bi-wiring.
2) Diapason. Bi-wiring seemed to produce more (artificial) "focus",
maybe even a more "tighty organized", deeper soundstage than single
wiring, but at the same time sharpness and artificiality was
introduced. Could have to do with different impedances for the highs
and the lows. The Diapason was rated 6 Ohms and the amp really needs 8
Ohms, so there was a mismatch to start with.
3) Audio Note. I didn't like the bi-wiring at all.
4) The Audio Notes are extremely sensitive to the type of
interconnection you use between the highs and the lows. The Diapason
and the Monitor Audio's were not.
I listened with simple copper cables and with AudioQuest Forest (not
so simple, by the way not my personal favorite, I know of other people
very happy with it).
So _for me_ bi-wiring is a fashion not to follow for the time being.
It _could_ make a difference for other amps and other speakers. I
don't know.
Ernesto.
Arthur Shapiro
>God bless John Dunlavy for his honesty and candor.
>
>My next set of higher-end will speakers will be Dunlavy's. No question.
>
>> Our DAL loudspeakers are equipped with input terminals that permit
>> bi-wiring - not because we believe that bi-wiring offers any audible
>> or measurable advantages - but because the lack of such input
>> terminals might impair sales.
>>
>> John D.
>
I can't argue with Mr. Dunlavy's opinion, and note that it's shared by others
such as JM Labs. My previous speakers, Legacy Sig IIIs, sounded better
biwired, and my current speakers (ESP Concert Grands) don't even provide
jumpers - they expect biwiring. As I already owned the biwired cabling I
never bothered to experiment.
I'd be interested if Mr. Dunlavy has a response to my observation about
single wiring his speakers on the top vs. the bottom terminals. The
difference IMHO was not particularly subtle, and intuitively surprised me.
Art
Guillaume Lemaire
crossover due to market pressure hype.
Audiophysic has "removed" the extra terminals on their new models I
believe.
To me a true test of the merits of bi wiring is to hook the speakers
up bi wired and listen with and without straps so as to keep the
extra cable out of the equasion. Also one strap on (-) terminals only
is interesting. Most people to whom I have demonstrated this have
preferred the sound with the straps in place, more coherent mid range
and integration of mid woofer and tweeter. Bi wired can sound a
little shrill but can appear to have better imaging and detail.
THE STRAPS: If single wiring a bi wire speaker replace those horrible
steel gold lacquered straps with some good wire. This will be the
most awesome cheap upgrade you may ever make to your stereo.
I have heard the difference between a variety of wires used as straps
on my Sonus Fabers and AEs. I connect to the top terminals (HF) as it
sounds cleaner and sweeter that way. Bottom connection gives more
bass.
Regards
Guillaume
Ed Sheffield <edshe...@home.com> wrote in message
news:9k9fjr$dkm$1...@bourbaki.localdomain...
Paul Lew
> In article <9kjvea$1bn$1...@bourbaki.localdomain>,
"GRL" <GLitw...@bigfoot.com> wrote:
>>God bless John Dunlavy for his honesty and candor.
>>
>>My next set of higher-end will speakers will be Dunlavy's. No question.
>>
>
>>> Our DAL loudspeakers are equipped with input terminals that permit
>>> bi-wiring - not because we believe that bi-wiring offers any audible
>>> or measurable advantages - but because the lack of such input
>>> terminals might impair sales.
>>>
>>> John D.
>>
> I can't argue with Mr. Dunlavy's opinion, and note that it's shared by others
> such as JM Labs. My previous speakers, Legacy Sig IIIs, sounded better
> biwired, and my current speakers (ESP Concert Grands) don't even provide
> jumpers - they expect biwiring. As I already owned the biwired cabling I
> never bothered to experiment.
My Dahlquist DQ-12 doc say "for maximum performance, bi-wire"; finally
decided to bi-wire last year and did hear an "improvement". No idea
whether a bit louder and clearer is an "improvement".
The wires used were just the 12 gage speaker wire from Radio Shack which
weren't that expensive; they were more flexible than the 12 gage romex
house wiring I've seen....
JohnDunlavy
The bottom set of input-terminals on all DAL loudspeakers are
connected only to the woofer drivers. The top set of terminals are
connected only to the mid and tweeter drivers.
Thus, if the gold-plated straps normally connecting the two sets of
terminals are removed and a single amp is connected only to one set
of terminals, the listener will be hearing only the woofers or the
mid/tweeters - obviously creating an audibly different sound! Hmmm!
But the ultra-low resistance of the gold-plated straps (probably less
than a few thousandths of an Ohm) could hardly be expected to create
an audible difference or degredation in accuracy.
Is there anyone that would like to bet a healthy sum of money on
being able to consistently identify an audible difference during a
true blind comparison?
Not me - and I have excellent hearing - as do several members of my
technical staff, none of whom believe in audible differences between
most cables - much less between the "straps" on the input connector
plate of our loudspeakers.
John D.
Steve Lampen
I have been reviewing the extensive posts on bi-wiring. Many of these
are old, but they leave me with some basic questions.
1. I have said in the past that a simple and dramatic test would be
to bi-wire a pair of speakers, have a person behind each speaker
change from bi-wiring to adding back the strap between high and low
in a random fashion, to record those random
connections/disconnections, and to have a group listening try and
tell (with perhaps 1 minute of music) if the speakers are bi-wired or
strapped. Then it would be simple to see what percentage they got
correct. Statistical analysis (bell curve) would be easily done.
Results beyond the standard curve would then open up the discussion
of what happens and what is heard.
2. If you are bi-wiring, what happens to the crossover. Since this
circuitry is intended to take a single pair of wires and divide the
power by frequency between the individual drivers, does using
bi-wiring go around this circuitry and feed the speakers
individually? Or is there a "filter" in each input removing the
frequencies not needed? Of course, bi-amping, with active and very
controllable frequency transitions, would be more accurate. In that
case, the wires go directly to the speakers. Having an circuitry of
any description between the amp and the speaker has to have a
dramatic effect on impedance, phase, and other parameters.
3. Which leads me to a third question. Has anyone done studies in
the lab on what is actually seen from the amp to the speaker in terms
of frequency, impedance, phase, (and, while we're at it, "back
EMF")? And then duplicate the tests for single-pair and bi-wired
hook-ups.
Personally, the transition between speakers is an area that I have
only seen casually mentioned, if at all, and the focus on cable is,
at least, poorly aimed. As a cable manufacturer, you might be
surprised that I am so interested in this subject. After all, when
people bi-wire they buy double the amount of wire, so should I
complain? Well, yes, the truth is, after all, our objective.
Steve Lampen
Technology Specialist, Multimedia Products
Belden Electronics Division
http://www.belden.com
Geoffrey Reynolds
>1. I have said in the past that a simple and dramatic test would be
>to bi-wire a pair of speakers, have a person behind each speaker
>change from bi-wiring to adding back the strap between high and low
>in a random fashion, to record those random
<snip>
I'd love to see the results of such a test.
>2. If you are bi-wiring, what happens to the crossover. Since this
>circuitry is intended to take a single pair of wires and divide the
>power by frequency between the individual drivers, does using
>bi-wiring go around this circuitry and feed the speakers
>individually? Or is there a "filter" in each input removing the
>frequencies not needed?
I would think that this would depend on the specific speakers, but in
most cases, the speakers will have 2 crossovers, 1 connected to each
pair of binding posts. Without the strap, what comes in on each pair
of posts goes only to 1 crossover. With the strap, everything goes to
both posts.
> Of course, bi-amping, with active and very
>controllable frequency transitions, would be more accurate. In that
>case, the wires go directly to the speakers. Having an circuitry of
>any description between the amp and the speaker has to have a
>dramatic effect on impedance, phase, and other parameters.
The wires go directly to the speakers only if the crossover circuitry
is removed from the speakers (or otherwise bypassed). I would think
that the main advantage here is that you can either choose an
amplifier that is optimum for each portion of the frequency range OR
you can use 2 identical amps, but each is only working with a chunk of
the frequency range, making for an easier job for the amp.
>3. Which leads me to a third question. Has anyone done studies in
>the lab on what is actually seen from the amp to the speaker in terms
>of frequency, impedance, phase, (and, while we're at it, "back
>EMF")? And then duplicate the tests for single-pair and bi-wired
>hook-ups.
In the case of biwiring, I think that in reality you are just moving
the jumper strap to the other end of the cable, which should result in
little if any difference in the sound. I'm of the opinion that the
frequencies knowing to only travel down the appropriate cable is bull
:).
That said, all of my speakers are currently biwired... I have B&W
Matrix 802 Series 3's, HTM, and 804's in my system. I went with
biwiring as the cable I selected had 4 conductors and adding the extra
connectors didn't change the cost by a significant amount.
See my next post for some questions about biamping...
>Personally, the transition between speakers is an area that I have
>only seen casually mentioned, if at all, and the focus on cable is,
>at least, poorly aimed. As a cable manufacturer, you might be
>surprised that I am so interested in this subject. After all, when
>people bi-wire they buy double the amount of wire, so should I
>complain? Well, yes, the truth is, after all, our objective.
I can see advantages to using double the amount of cable. I can also
(potentially) see advantages to using high quality cable in place of
the jumpers that are included with most speakers. I can't see any
legitimate advantages to biwiring in and of itself.
Obviously, this is mostly my opinion, not a careful scientific
study...
--
Geoffrey Reynolds
jfuentes
difference does it make if the audio signal jumps to the second set
of posts earlier or later (across the bus bar at the speaker vs.
splits off of the receiver terminals), it all gets to the same
place. The cross overs do not get involved until after the signal go
into the cabinet of the speaker anyway. That is my EE side talking.
I am open to those that have more experience in audio than I for
insight. Perhaps basic, conventional principles in electromotive
propagation and conductivity are not sufficient and there is more to
it?
Please explain.
Jon
"Geoffrey Reynolds" <grey...@newsguy.com> wrote in message
news:9o5b0r$hd6$1...@bourbaki.localdomain...
Hans Looman
> I too have questioned the value of bi-wiring. After all, what
> difference does it make if the audio signal jumps to the second set
> of posts earlier or later (across the bus bar at the speaker vs.
> splits off of the receiver terminals), it all gets to the same
> place. The cross overs do not get involved until after the signal go
> into the cabinet of the speaker anyway. That is my EE side talking.
The big advantage of bi-wiring is found in minimizing the influence
of back EMF from bass to mid-high sections of the speakers and vice
versa. Since the output impedance of the amplifier should be almost
zero the amp will shortcircuit this influence. The filter sections in
the speakers do not see eachother anymore. In a one wire situation it
is the impedance of this wire that will substantially lower the amp's
ability to do so, because it acts as a shared impedance for bass and
mid-high range signals. The listening experience difference between
single- and bi-wiring depends a lot on the design of the internal
filters in the speakers, quality of the cable and impedance (damping
factor) of the amplifier/speaker combination.
Regards,
--
Hans Looman (loo...@eldevs.nl)
Eldevs Electronic Devices BV
Kattegat 4C
3446 CL WOERDEN
The Netherlands
Aldo Pignotti
the amp and the speaker. If your speaker wire isn't big enough
to carry the signal then doubling it up will certainly help.
Norm Strong
>the amp and the speaker. If your speaker wire isn't big enough
>to carry the signal then doubling it up will certainly help.
>
The problem with that hypothesis is that only the current for one portion of
the signal will flow through any given wire when it's biwired. The only place
at which the wires share the load is right at the xover frequency. Both high
and low frequencies will still see just the one wire.
Norm Strong (nh...@aol.com)
Seattle WA
Aldo Pignotti
..on two separate wires, you've split the load in two. you've doubled the copper.
there's only one source that is sending out a full frequency signal.
Stewart Pinkerton
No, you haven't, except around the crossover area. High frequencies go
only to the tweeter, low frequencies go only to the woofer. Hence,
there is *no* doubling of the copper except for that brief area around
the crossover. Even there the power is equally divided, otherwise
there would be a hump in the frequency response of the speaker.
>there's only one source that is sending out a full frequency signal.
Yes. So what?
--
Stewart Pinkerton | Music is art, audio is engineering
Aldo Pignotti
> aldopi...@yahoo.com (Aldo Pignotti) writes:
> >
> >..on two separate wires, you've split the load in two. you've doubled the copper.
>
> No, you haven't, except around the crossover area. High frequencies go
> only to the tweeter, low frequencies go only to the woofer. Hence,
> there is *no* doubling of the copper except for that brief area around
> the crossover. Even there the power is equally divided, otherwise
> there would be a hump in the frequency response of the speaker.
>
> >there's only one source that is sending out a full frequency signal.
>
> Yes. So what?
what splits the signal? you said "High frequencies go only to the
tweeter." why is that? the tweeter and the circuitry with the
tweeter may only use the high frequency information but the full
signal is there. biwiring doubles the copper going to the speakers.
Howard Ferstler
>
> ste...@pinkertons.fsnet.co.uk (Stewart Pinkerton) wrote in message news:<9og385$ckp$1...@bourbaki.localdomain>...
> > aldopi...@yahoo.com (Aldo Pignotti) writes:
>
> > >
> > >..on two separate wires, you've split the load in two. you've doubled the copper.
> >
> > No, you haven't, except around the crossover area. High frequencies go
> > only to the tweeter, low frequencies go only to the woofer. Hence,
> > there is *no* doubling of the copper except for that brief area around
> > the crossover. Even there the power is equally divided, otherwise
> > there would be a hump in the frequency response of the speaker.
> >
> > >there's only one source that is sending out a full frequency signal.
> >
> > Yes. So what?
> what splits the signal?
The crossover in the speaker box.
>you said "High frequencies go only to the
> tweeter." why is that?
Because the crossover will only let high frequencies pass
through the wire going to the high-frequency connection on
the speaker hookup. Low frequencies cannot pass down through
the wire going to the high-frequency hookup, because the
crossover is blocking those low signals. Just the opposite
happens with the low-frequency hookup.
> the tweeter and the circuitry with the
> tweeter may only use the high frequency information but the full
> signal is there.
The voltage pressure is there, but only high-frequency
current is flowing through the wire. Only low-frequency
current flows through the low-frequency hookup, for the same
reasons.
> biwiring doubles the copper going to the speakers.
No it does not. The wire run to the woofer section only
carries the lower frequencies, because the crossover
downstream will only let signals like that flow. The wire
run to the mid/tweeter section only carries the higher
frequencies, because the crossover only lets those signals
flow through the hookup to those external leads.
At and near the crossover point there is an overlap, since
both sets of drivers will share the load, and over that
range current will flow through both sets of wires. However,
at definite high and low frequencies, only one set of wires
is carrying significant current.
This is fairly easy to diagram if you use a pencil to sketch
the runs to the speaker from the amp, through the crossover,
and then to the drivers.
Howard Ferstler
Arny Krueger
news:9oq8a...@enews2.newsguy.com...
It doubles the copper, but neither cable is in parallel with the
other over the full audio range. So, from the standpoint of the wire
gauge that is serving each half of the speaker system, the series
resistance is the same as if only one wire was being used.
Bi wiring mainly benefits the person selling the wire. Bi wire = buy
wire!
Hans Looman
news:9oqha...@enews1.newsguy.com...
IMO the coil / magnet systems in both sections of the speaker
generate back EMF, since they are moving coils in magnetic fields.
Especially at crossover frequencies there will be signal from the low
section influencing the midrange section and vice versa.
Using bi-wiring low and mid cannot see eachother anymore, since there
is an almost zero ohm amplifier shortcircuiting the backflowing
current in between.
--
Hans Looman (loo...@eldevs.nl)
Eldevs Electronic Devices BV
WOERDEN - The Netherlands
SdW
>Using bi-wiring low and mid cannot see eachother anymore, since there
>is an almost zero ohm amplifier shortcircuiting the backflowing
>current in between.
In what way would it matter if "low and mid" are able to "see"
eachother? What is the function of the crossover filter, then?
And by "low and mid", are you referring to current, voltage or
both (power) ?
BTW, the "zero ohm" amplifier cannot be considered a short
circuit, because it is the *power source*, delivering the signal.
Could you clarify this a bit for me? Thanks in advance.
--
Sander deWaal
Arny Krueger
news:9osrh...@enews4.newsguy.com...
> > > > Yes. So what?
The essence of back EMF is that the impedance of the driver becomes
higher than what would be predicted by solely the speaker's DC
resistance. Since the speaker driver is passive, the back EMF never
appears as an excess voltage, just reduced current drain. Therefore
more back EMF the higher the impedance the speaker has, and the less
the speaker depends on a very high quality speaker wire for proper
operation.
> Especially at crossover frequencies there will be signal from the low
> section influencing the midrange section and vice versa.
That's one of the things that crossovers are for - keeping the upper
range driver isolated, as necessary; from the power amp and the lower
range driver. You have to remember that the bi-wired cables are still
shorted to each other at the terminals of the power amplifier, so
such additional isolation as biwiring may provide is limited to the
impedance of the speaker cable itself. If the speaker wire has
desirably low impedance, then the benefit of bi-wiring is reduced.
> Using bi-wiring low and mid cannot see each other anymore, since there
> is an almost zero ohm amplifier short-circuiting the back-flowing
> current in between.
If the speaker cable has low impedance, and all quality speaker
cables do, then the power amplifier's short-circuiting effect is
largely present at the speaker terminals.
The purpose of the crossover is to isolate the woofer and the tweeter
from each other and the power amp. To put this into perspective, the
out-of-band isolation provided by the crossover can be measured and
it is often in the range of 10's of dBs. With good speaker cables,
the additional isolation provided by bi-wring is on the order of
100ths or 10ths of a dB, if it exists at all.
Let's say that you have so many ounces of copper to put into speaker
cable. If you bi-wire then half of the copper benefits each driver in
a 2-way speaker. More copper, less voltage variation at the input
terminals to the speaker. If you single-wire then all of he copper
benefits each driver in a 2-way speaker. Which is better?
L. David Matheny
on different amounts of current in the high and low wires. To
see if this could be significant, biwire a pair of speakers and
then use a scope to observe the difference between the high
and low signals at one of the speakers. (Be careful to set
the scope up so you aren't grounding any hot terminal. This
might require a dual-trace scope used in some sort of
differential mode.) If you see any difference, that voltage
might reasonably affect the sound; if you see no difference,
biwiring should be worthless, at least for that speaker.
"jfuentes" <fuen...@earthlink.net> wrote in message
news:9o7qc...@enews1.newsguy.com...
> I too have questioned the value of bi-wiring. After all, what
> difference does it make if the audio signal jumps to the second
> set of posts earlier or later (across the bus bar at the speaker
> vs. splits off of the receiver terminals), it all gets to the same
> place. The cross overs do not get involved until after the signal
> go into the cabinet of the speaker anyway. That is my EE side
> talking.
>
> I am open to those that have more experience in audio than I for
> insight. Perhaps basic, conventional principles in electromotive
> propagation and conductivity are not sufficient and there is more
> to it?
>
> Please explain.
>
> Jon
>
<snip>
Howard Ferstler
With biwiring, both sets of terminals will be hooked to the
amp in parallel, and they will be connected at a common
terminal on that amplifier. On a schematic, this would
simply be shown as a slight increase in resistance between
the mid/tweeter section and the woofer section, with the
increased resistance being that of the wires. The amp will
have nothing to do with this.
Actually, the crossover may be designed for optimum
performance with very little resistance being between the
woofer and tweeter/mid sections, since there are normally
only short jumpers between those sections on the back of the
speaker. However, replacing that very low resistance with
the resistance of two sets of wires (still low, but
obviously not as low as the jumpers) might introduce
artifacts into the crossover topology that actually slightly
degrades the sound at and near the crossover point. No big
deal, probably, but no improvement, either.
Now, if you are talking about bi-AMPING, then things will be
quite different, since then there will indeed be total
isolation between the mid/tweeter and woofer sections.
Howard Ferstler
Arny Krueger
news:9ot3u...@enews2.newsguy.com...
> BTW, the "zero ohm" amplifier cannot be considered a short
> circuit, because it is the *power source*, delivering the signal.
> Could you clarify this a bit for me? Thanks in advance.
A power source is thought of, theoretically, as being composed of a
voltage source and a series resistor, or a current source in paralell
with a resistor.
In either case the resistor is equivalent to the source impedance of
the actual power source.
In the case of the usual "high damping factor" SS power amplifier,
the resistor is very small - close to being a short circuit. For
example, a power amp with a *damping factor* of 80 for an 8 ohm load
has a source impedance of 0.1 ohm.
Richard D Pierce
Hans Looman <loo...@eldevs.nl> wrote:
>IMO the coil / magnet systems in both sections of the speaker
>generate back EMF, since they are moving coils in magnetic fields.
Only at those frequencies where the motional impedance of the
drivers is high, and that ONLY occurs at the fundamental
mechanical resonance of the drivers.
>Especially at crossover frequencies there will be signal from the low
>section influencing the midrange section and vice versa.
False: at crossover frequencies, the motional impedance of the
drivers is low. First, the crossover frequency is most often
quite far away from the woofer's mechnical resonance. Second,
the tweete's mechnical resonance is more highly damped
>Using bi-wiring low and mid cannot see eachother anymore, since there
>is an almost zero ohm amplifier shortcircuiting the backflowing
>current in between.
And, as is omost often ignored in the idiotic "damping
factor" case, this "EMF generator" is ALSO isolated by the
simple ohmic resistance of the voice coil, which FAR exceeds ANY
resistance seen in the speaker cables, except in the most
pathological of cases.
The problem with most "technical" justifications of bi-wiring,
a typical example of which is seen above, is that they are
WOEFULLY incomplete. They seize on a SINGLE second-order effect,
while conveniently ignoring far more dominate first order
effects.
Richard D Pierce
Hans Looman <loo...@eldevs.nl> wrote:
>IMO the coil / magnet systems in both sections of the speaker
>generate back EMF, since they are moving coils in magnetic fields.
Only at those frequencies where the motional impedance of the
drivers is high, i.e, the motion of the drivers is large, and
that ONLY occurs at the fundamental mechanical resonance of
the drivers. At ALL other frequencies, the so-called "back-EMF"
is effectively nonexistent, as evidenced by the fact that the
resulting electrical impedance is wholly dominated by the DC
resistance or simple electrical inductance of the voice coil.
And, just for the record, that "back-EMF" so often invoked as
some mysterious voltage generating demon is NO different than
the same "demon" in any other resonant circuit, such as a
simple parallel RLC tank circuit.
>Especially at crossover frequencies there will be signal from the low
>section influencing the midrange section and vice versa.
False: at crossover frequencies, the motional impedance of the
drivers is low. First, the crossover frequency is most often
quite far away from the woofer's mechanical resonance. Second,
the tweeter's mechanical resonance is more highly damped
>Using bi-wiring low and mid cannot see eachother anymore, since there
>is an almost zero ohm amplifier shortcircuiting the backflowing
>current in between.
And, as is most often ignored in the oft-invoked but incorrect
"damping factor" argument, this "EMF generator" is ALSO isolated
+KaRkUs+
<hfer...@mailer.fsu.edu> wrote:
>Now, if you are talking about bi-AMPING, then things will be
>quite different, since then there will indeed be total
>isolation between the mid/tweeter and woofer sections.
>
>Howard Ferstler
Bi amping or tri amping is THE way to go IMHO. It's expensive but well
worth it IMHO.
KaRkUs.
Howard Ferstler
It does require the careful use of some measuring hardware,
however, in order to get the balances between the drivers
properly done. And I really am not sure that it makes a
great deal of difference in overall sound if a solo amp and
the passive crossover networks are good quality.
I think that bi- and tri-amping will allow the user to
maladjust the bass/mid/treble balance easily, and the
results might be seen as superior to a single amp and fully
passive crossover that was optimized to work with the system
drivers and deliver genuinely flat output.
Howard Ferstler
Mark Wilkinson
> It does require the careful use of some measuring hardware,
> however, in order to get the balances between the drivers
> properly done. And I really am not sure that it makes a
> great deal of difference in overall sound if a solo amp and
> the passive crossover networks are good quality.
>
> I think that bi- and tri-amping will allow the user to
> maladjust the bass/mid/treble balance easily, and the
> results might be seen as superior to a single amp and fully
> passive crossover that was optimized to work with the system
> drivers and deliver genuinely flat output.
>
> Howard Ferstler
Most bi-, or tri-amped designs I've read about (prosound) use active
x-overs, and the manufacturers seem pretty adamant the settings should
remain fixed as calibrated by the factory. I've got a prosound quad-amped
speaker that uses an active x-over that is unadjustable (for the reasons you
mention). The speaker uses an integral 4 channel amp and sounds damn good
(and oh so loud with gut vibrating bass :)
I'd like to see consumer speakers start adapting prosound techniques --
speakers with an integral amp for each individual driver, driven by an
integral active, phase corrected x-over. As well as works for prosound
gear, I gotta believe it might improve consumer gear. Mark
meengr
At one time I was running Martin Logan Sequell II's from a well
restored Hafler DH-220. Then I aquired a Parasound HCA800II and liked
its sound with the ML's a bit better. I then played around with
Bi-amping using the two amps - the Parasound has output level
controls so I was able to balance things pretty well. Eventually
settled on the DH-220 for bass and the HCA800 on panels as the best
combination, and significantly better then either amp alone.
Eventually tried Adcom 565 monos full range and that was far better
than the bi-amped system in all respects.
IMHO there are lots of vaiables in these types of speaker/amp systems
and I wouldn't commit a big sum of money without some serious
comparison testing
Norm Strong
>>quite different, since then there will indeed be total
>>isolation between the mid/tweeter and woofer sections.
>>
>>Howard Ferstler
>
>Bi amping or tri amping is THE way to go IMHO. It's expensive but well
>worth it IMHO.
>
>KaRkUs.
Bi-amping is not only practical but cheap--if it comes in the form of an active
speaker. The advantages of integrating the speaker and its necessary
amplification are so great that I hve a hard time understanding the reluctance
of the average audiophile to embrace the idea. Maybe it's the "mother, I'd
rather do it myself" syndrome. Every problem related to speaker and power amp
is solved by integration:
1. No speaker wire to worry about
2. No passive crossover (a rather expensive item)
3. No concerns over the impedance characteristics of the speaker and how it
might affect the choice of amplifier.
4. No possibility of overload.
5. Frequency response of amplifier can be tailored to compensate for driver
failings.
6. Can be cheaper, since the cost of selling the amplifier can be folded into
one sale.
I could go on.
+KaRkUs+
wrote:
>I think that bi- and tri-amping will allow the user to
>maladjust the bass/mid/treble balance easily, and the
>results might be seen as superior to a single amp and fully
>passive crossover that was optimized to work with the system
>drivers and deliver genuinely flat output.
>
>Howard Ferstler
Fortunately I know what to adjust and to what level to achive that
response you talk about :)
It's not that hard Howard, really it isn't.
KaRkUs.
dwoz
people get it so very wrong?
dwoz
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