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Scott Dorsey Scott Dorsey is offline
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Default Help wiring speakers

Nigel Goodwin wrote:

It's not down to output 'resistance' (should be impedance anyway), it's
mostly down to the power supply that can't supply enough power. The
output impedance of transistor amplifiers is extremely low, tiny
fractions of an ohm.


No, the output impedance get actually pretty high at low frequencies,
BECAUSE the power supply can't supply enough power.

The actual amplifier impedance is the series impedance (mostly resistive)
of the output stage, PLUS the impedance (mostly capacitive) of the power
supply.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Brian Running Brian Running is offline
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Heat is about current.

Actually, no. Drop a bazillion amps through 0 ohms and, no poof!
because no heat.


Actually, yes. Take a conductor with a high resistance, and put no
current through it, and poof! No heat.

Current is the flow of electrons,


Actually, no. Current is defined as the flow of charge.


Actually, yes. Charge is a measure of the quantity of electrons. A
coulomb is a definite quantity of electrons. When those electrons move,
it's current. Current is the flow of electrons.

and it is the
physical flow of electrons that causes the heat.


Actually, no. It is the thermal agitation of atoms and molecules
caused by the interruption of flow of current that is heat.


Actually, yes. It's the movement of the free electrons within the
conducting material that causes the heat.

Conductors and devices
are rated for current flow, not for power, because current is the actual
physical phenomenon that generates the heat.


Actually, no. Conductors are rated for current flow over a
certain length,


Actually, yes. They're rated by their cross-section, and it's dependent
upon the material they're made of.

Consider, as a practical example, the required
rating for a 100' extension cord carrying 15 amps, and a
15 amp fuse: the cross sections are radically different,
yet they have the same current carrying capacity.


And that would be a meaningful comparison if they were made of the same
conductor material. But they aren't.

The rise in temperature is determined by the rate in which
the heat is inserted into the system


From where? What's the source of the heat? Go ahead, say it: It's
the current flowing through the conductor.

And a quick check of the fundamental
units used for these calculations reveals it to be something
called "watts."


Because watts are a unit of power, which is what's used to measure the
work done or the heat dissipated. That doesn't change the fact that
it's electric current through a conductor that causes the heat in the
first place.

Current alone is NO determing factor of heat production. The
same current through two different systems having two different
resistances will produce two different amounts of heat.


It's the most basic factor in heat production in an electrical
conductor. Without current, there won't be any heat generated -- can't
get more fundamental than that.

Without a single exception, you will find the heat produced
to be a direct function of power, not of current.


That's just plain wrong. Power is determined by current. No current,
no power. Power measures the amount of heat generated, or work done,
but it's the electrical current that is fundamentally making the power
and causing the heat.
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Brian Running wrote:
Heat is about current.


Actually, no. Drop a bazillion amps through 0 ohms and, no poof!
because no heat.


Actually, yes. Take a conductor with a high resistance, and put no
current through it, and poof! No heat.


Actually, a bazillion amps *won't go* though 0 ohms because the door is
shut. However, I'm sure one can Google up the formula for heat
generated by electrical current. Or Power.
--
Mike.

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Mike Hanson wrote:
Brian Running wrote:
Heat is about current.
Actually, no. Drop a bazillion amps through 0 ohms and, no poof!
because no heat.

Actually, yes. Take a conductor with a high resistance, and put no
current through it, and poof! No heat.


Actually, a bazillion amps *won't go* though 0 ohms because the door is
shut. However, I'm sure one can Google up the formula for heat
generated by electrical current. Or Power.


0 ohms is just that, a superconductor, and researchers have put millions
of amps through superconducting rings to get huge magnetic fields. The
problem is that if they heat up enough to have **any** resistance the
current can cause so much heat the now non-superconductor can explode
from the stored energy.
Power is current squared times resistance.
Bill Baka
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Bill wrote:
Mike Hanson wrote:

Actually, a bazillion amps *won't go* though 0 ohms because the door is
shut. However, I'm sure one can Google up the formula for heat
generated by electrical current. Or Power.


0 ohms is just that, a superconductor, and researchers have put millions
of amps through superconducting rings to get huge magnetic fields. The
problem is that if they heat up enough to have **any** resistance the
current can cause so much heat the now non-superconductor can explode
from the stored energy.
Power is current squared times resistance.
Bill Baka


Yes. I was of course thinking of infinite resistance and should stop
writing two-sentence posts when it's very late and I'm tired. On the
other hand, it generated your response. Nice to meet you, Bill. :-)
--
Mike.



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I'd suspect your lack of bass is caused by the design of the cabinet as
well.

And being a bassist, let me say that a lot of guitarists use too much bass,
and they don't need to, if they are playing with a bassist. Playing with
the amp settings when you are alone is great and all, but you should NOT use
those same settings when the band shows up. You all need to share the sonic
space, and... give the bassist the bass duties. Stay up in guitar range.
As a band... your sound will be much better.

--
-rob Bartlett, TN
O
/(\)
^^
"Ka-el" wrote in message
oups.com...

Mike Rivers wrote:

These people will bicker forever over words and not really answer your
question. But the problem is that we don't really know what your
question is. Several people have explained how impedances combine in
series and parallel, but you won't really get any more assistance than
that until you let us know WHY you want to "upgrade" to 8 ohm speakers.
Do you just haver some 8 ohm speakers that you think sound better than
the originals?


Thanks for your reply.. I started to get a headache just reading all
the inputs
My problem is No low-end at all my 4x10 Hartke guitar cabinet.. my
amp is a Peavy XXL
which sounds better on my Buddy's Marshall cabinet..

What amplifier are you using it with? Is it a Hartke amplifier, or just
a Hartke speaker cabinet? What is the power rating and impedance of the
amplifier? If you're trying to make it louder, you may not be able to
do so. One amplifier may have its peak power at 4 ohms, while another
may have its peak power at 2 ohms, or 8 ohms, but all be called "100
watts."


Just wanna get some more rumble or bass on my Amp.. I was told the
Stock Celestion
on the Hartke GH410a cabinet is crap ?

Also, that stereo/mono wiring with a switch sounds pretty complicated.
Do you need to retain that capability?


I would like to retain that Stereo monitoring switch, but whichever
way that works w/ four 8 Ohms speakers is fine.



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Default Help wiring speakers

In rec.audio.pro Brian Running wrote:
Heat is about current.


Actually, no. Drop a bazillion amps through 0 ohms and, no poof!
because no heat.


Actually, yes. Take a conductor with a high resistance, and put no
current through it, and poof! No heat.

Current is the flow of electrons,


Actually, no. Current is defined as the flow of charge.


Actually, yes. Charge is a measure of the quantity of electrons. A
coulomb is a definite quantity of electrons. When those electrons move,
it's current. Current is the flow of electrons.

and it is the
physical flow of electrons that causes the heat.


Actually, no. It is the thermal agitation of atoms and molecules
caused by the interruption of flow of current that is heat.


Actually, yes. It's the movement of the free electrons within the
conducting material that causes the heat.

Conductors and devices
are rated for current flow, not for power, because current is the actual
physical phenomenon that generates the heat.


Actually, no. Conductors are rated for current flow over a
certain length,


Actually, yes. They're rated by their cross-section, and it's dependent
upon the material they're made of.

Consider, as a practical example, the required
rating for a 100' extension cord carrying 15 amps, and a
15 amp fuse: the cross sections are radically different,
yet they have the same current carrying capacity.


And that would be a meaningful comparison if they were made of the same
conductor material. But they aren't.

The rise in temperature is determined by the rate in which
the heat is inserted into the system


From where? What's the source of the heat? Go ahead, say it: It's
the current flowing through the conductor.

And a quick check of the fundamental
units used for these calculations reveals it to be something
called "watts."


Because watts are a unit of power, which is what's used to measure the
work done or the heat dissipated. That doesn't change the fact that
it's electric current through a conductor that causes the heat in the
first place.

Current alone is NO determing factor of heat production. The
same current through two different systems having two different
resistances will produce two different amounts of heat.


It's the most basic factor in heat production in an electrical
conductor. Without current, there won't be any heat generated -- can't
get more fundamental than that.


Its more basic than resistance? Without reisitance, there won't be any heat
generated -- can't get more fundamental than that.

--
Aaron
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Mike Hanson wrote:
Bill wrote:
Mike Hanson wrote:
Actually, a bazillion amps *won't go* though 0 ohms because the door is
shut. However, I'm sure one can Google up the formula for heat
generated by electrical current. Or Power.

0 ohms is just that, a superconductor, and researchers have put millions
of amps through superconducting rings to get huge magnetic fields. The
problem is that if they heat up enough to have **any** resistance the
current can cause so much heat the now non-superconductor can explode
from the stored energy.
Power is current squared times resistance.
Bill Baka


Yes. I was of course thinking of infinite resistance and should stop
writing two-sentence posts when it's very late and I'm tired. On the
other hand, it generated your response. Nice to meet you, Bill. :-)


I mostly just hang out but some things are so obvious, to me at least,
as an electronics engineer, that I have to reply. Audio is a hobby for
me but I will try to help when the answer seems apparent to me.
Bill Baka
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Scott Dorsey wrote:
anahata wrote:
I take your point, but I'm suggesting or assuming that an amplifier
rated at 500W into 2 ohms will have lower output device resistances than
a different amplifier rated at 500 W into 8 ohms.


This isn't a good assumption to make. In fact, the two could even be the
same amplifier!

A typical amplifier rated at 500W into 8 ohms should also be rated 2000W
into 2 ohms, and therefore ought to have _lower_ device resistance than
an amplifier rated at 500W into 2 ohms.

Unfortunately many don't. Which is why a lot of amplifiers rated 500W
into 8 ohms are only rated 1500W into 2 ohms... where is that other 500W
going?
--scott


HEAT...

--
www.google.com enter
searchinsert query here enter

avoiding newsgroup wiseasses.... PRICELESS.

For some things there is usenet
For everything else there is google.............

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I really appreciate your inputs.. I just think, it's not worth the time
and hussle or messing around on this 4x10 guitar cabinet.. I'll
problaby just buy a 2x12 cab from Avatar w/ Celestion V30 and G12H30..
Thanks for all the help!!

Mike Rivers wrote:
Ka-el wrote:

My Peavy XXL Amp does have that multi Ohm output 4-8-16 Ohm


It's not clear how this switch works (no schematic available). It could
switch taps on a transformer, or it could just be a trick. However, you
can wire four 8-ohm speakers in parallel which gets you 2 ohms, and
that's not recommended by Peavey. You can also wire them to get 8 ohms
by putting two parallel pairs in series, or two series pairs in
parallel. Speaker purists will argue advantages and disadvantages of
each based on speaker damping. So if the amplifier's impedance switch
is for real, you can match them to the amplifier by setting the switch
to 8 ohms.

In your cabinet's stereo mode, you can have either two 4 ohm pairs or
two 16 ohm pairs. However, since your amplifier doesn't have a stereo
output (the two jacks are in parallel) there's only one logical reason
to do this, and that's if you want to use that cabinet with some other
amplifier that does have two channels (or with two amplfiers). But then
you're getting into a different sound because you'll be using those
speakers with another amplifier.

So, again, I think you're looking at the wrong solution to the problem
of not liking the sound of your bass when you play it through that
cabinet with that amplifier.




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Avatars rock, and a 2x12 SHOULD be enough for any geetarist. Lord knows, it
will be enough for any audience member.

-owner of 2x10 and 1x15 Avatars.
--
-rob Bartlett, TN
O
/(\)
^^
"Ka-el" wrote in message
oups.com...
I really appreciate your inputs.. I just think, it's not worth the time
and hussle or messing around on this 4x10 guitar cabinet.. I'll
problaby just buy a 2x12 cab from Avatar w/ Celestion V30 and G12H30..
Thanks for all the help!!

Mike Rivers wrote:
Ka-el wrote:

My Peavy XXL Amp does have that multi Ohm output 4-8-16 Ohm


It's not clear how this switch works (no schematic available). It could
switch taps on a transformer, or it could just be a trick. However, you
can wire four 8-ohm speakers in parallel which gets you 2 ohms, and
that's not recommended by Peavey. You can also wire them to get 8 ohms
by putting two parallel pairs in series, or two series pairs in
parallel. Speaker purists will argue advantages and disadvantages of
each based on speaker damping. So if the amplifier's impedance switch
is for real, you can match them to the amplifier by setting the switch
to 8 ohms.

In your cabinet's stereo mode, you can have either two 4 ohm pairs or
two 16 ohm pairs. However, since your amplifier doesn't have a stereo
output (the two jacks are in parallel) there's only one logical reason
to do this, and that's if you want to use that cabinet with some other
amplifier that does have two channels (or with two amplfiers). But then
you're getting into a different sound because you'll be using those
speakers with another amplifier.

So, again, I think you're looking at the wrong solution to the problem
of not liking the sound of your bass when you play it through that
cabinet with that amplifier.




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Plays Real Basses wrote:
Scott Dorsey wrote:
Unfortunately many don't. Which is why a lot of amplifiers rated 500W
into 8 ohms are only rated 1500W into 2 ohms... where is that other 500W
going? --scott

HEAT...


To explain a bit more, the heat in an amplifier's output devices is
a function of the output current and the *supply rail* voltage, not
the output voltage. To push 500W into 8 ohms, the voltage swing at
the output must be at least 90V peak, or 180V P-P. The output devices
need to be still running in a linear mode before clipping, so the
actual supply rails will normally be 5-7 volts more, say 195V rail
to rail.

When the output is at half the rail, the current (assuming a
resistive load - not the case actually) is over 5 amps, and the
output device on that side is dissipating just under 300 watts.
Now assume an inductive load with a phase angle of 45 degrees.
The maximum current of over 10 amps is reached at the half-rail
voltage on the descending side. The maximum dissipation in the
output devices occurs somewhat after that, when it reaches perhaps
700W (ballpark figures). The ratio of output power to wasted
power is much less with a reactive load.

If you use a lower impedance driver, you reach maximum current at
lower output voltages, so the voltage across the output devices
is *greater*. The effect is that the safe output power will be
less with low 2 ohm speakers than with 8 ohm ones.

I deliberately didn't go into the maths here, but I hope this has
gone some way to answer your question.
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Clifford Heath wrote:
To explain a bit more, the heat in an amplifier's output devices is
a function of the output current and the *supply rail* voltage


Hooray! I was wondering how long it would be before someone reminded us
all that power (and hence heat) has something to do with *voltage*, as
well as current.

I can't be bothered to say more. The rest of it's been covered
more-or-less by various posts in the thread.

--
Anahata
-+- http://www.treewind.co.uk
Home: 01638 720444 Mob: 07976 263827
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Plays Real Basses wrote:
Scott Dorsey wrote:
anahata wrote:
I take your point, but I'm suggesting or assuming that an amplifier
rated at 500W into 2 ohms will have lower output device resistances
than a different amplifier rated at 500 W into 8 ohms.


This isn't a good assumption to make. In fact, the two could even be
the same amplifier!

A typical amplifier rated at 500W into 8 ohms should also be rated 2000W
into 2 ohms, and therefore ought to have _lower_ device resistance than
an amplifier rated at 500W into 2 ohms.

Unfortunately many don't. Which is why a lot of amplifiers rated 500W
into 8 ohms are only rated 1500W into 2 ohms... where is that other 500W
going? --scott


HEAT...

For raw power, one of the new things coming out of the chip
manufacturers labs is PWM, or Pulse Width Modulation so that the output
transistors are either fully on or fully off. So far they have it
working with low power audio and are thinking of making it standard in
cell phones to save even more power. No fidelity there though.
I did a project with it a few years back for motor control with an
output bandwidth up to 1KHz and distortion was not an issue there but I
was putting out about a hundred watts with a 50KHz pulse frequency and
very little transistor heat. I don't know if any manufacturers of high
power audio will try to go that way for a while, but I have heard it
mentioned for consumer audio equipment up to about 50 watts.
Right now, it is a wait and see.
Bill Baka
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Bill wrote:
For raw power, one of the new things coming out of the chip
manufacturers labs is PWM, or Pulse Width Modulation


Hardly new, there have been commercial products based on it for
at least 25 years.

I don't know if any manufacturers of high
power audio will try to go that way for a while, but I have heard it
mentioned for consumer audio equipment up to about 50 watts.


They've been doing it for years now. The pro audio market for
class-D amplifiers with high power output is what one would
call "mature." TI, National and other major semiconductor
manufacturers have had high-power, wide-band integrated
IC PWM class D parts for quite some time.

Try a simple web search for "class D" and ""PWM audio amplifier"
and you will get tens of thousands of hits, many of which point
to existing products you can buy now with power ranging from
a few milliwatts to hundreds of watts, specifically for high-quality
audio applications.



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Ka-eL wrote:
Hi Group!!, Novice in wiring here.. I have a Guitar Cabinet Hartke
(4x10) GH410a that has four 16 Ohms speaker, w/ 4 or 16 Ohm mono and 8
Ohm stereo switch on the input Jack.. I would like to upgrade the
speakers to four 8 Ohm.. No knowledge in impedance on speakers, but
I've heard that I need to revise my wiring? and find out what is the
total Ohm of the cabinet? w/ the switch from Mono 4-16 Ohm and Stereo 8
Ohm.. what will be my cabinet Ohm? do I need to replace the speaker
Jack inputs for 8 Ohm? I appreciate any Help!!



I've read the replies and your responses to them. Mike River's advice
is the best, sell the Hartke and get a cabinet you like.

A potential problem I haven't seen discussed is that since you haven't
learned a lot about electronics and wiring, do you know how to solder?
It's not real hard, either, but some experience in doing it helps avoid
cold solder joints and other problems.

If you need to get someone else to actually do the wiring, I think
you'll find it cheaper to sell the Hartke and buy a used cabinet that
works the way you want. Clearly, a 4 X 10 cabinet can give you the
sound you like, but they're not all created equal.

-Raf


--
Misifus-
Rafael Seibert

blog: http://rafsrincon.blogspot.com/
Photos: http://www.flickr.com/photos/rafiii
home: http://www.rafandsioux.com

--
Posted via a free Usenet account from http://www.teranews.com

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"Bill" wrote in message
. ..
Plays Real Basses wrote:
Scott Dorsey wrote:
anahata wrote:
I take your point, but I'm suggesting or assuming that an amplifier
rated at 500W into 2 ohms will have lower output device resistances
than a different amplifier rated at 500 W into 8 ohms.

This isn't a good assumption to make. In fact, the two could even be
the same amplifier!

A typical amplifier rated at 500W into 8 ohms should also be rated

2000W
into 2 ohms, and therefore ought to have _lower_ device resistance than
an amplifier rated at 500W into 2 ohms.

Unfortunately many don't. Which is why a lot of amplifiers rated 500W
into 8 ohms are only rated 1500W into 2 ohms... where is that other

500W
going? --scott


HEAT...

For raw power, one of the new things coming out of the chip
manufacturers labs is PWM, or Pulse Width Modulation so that the output
transistors are either fully on or fully off. So far they have it
working with low power audio and are thinking of making it standard in
cell phones to save even more power. No fidelity there though.
I did a project with it a few years back for motor control with an
output bandwidth up to 1KHz and distortion was not an issue there but I
was putting out about a hundred watts with a 50KHz pulse frequency and
very little transistor heat. I don't know if any manufacturers of high
power audio will try to go that way for a while, but I have heard it
mentioned for consumer audio equipment up to about 50 watts.
Right now, it is a wait and see.
Bill Baka


There are, and have been for some time, amps in the kilowatt and higher
range using PWM. Your info is 20 years old.



--
Posted via a free Usenet account from http://www.teranews.com

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"Bill" wrote in message
. ..
Plays Real Basses wrote:
Scott Dorsey wrote:
anahata wrote:
I take your point, but I'm suggesting or assuming that an amplifier
rated at 500W into 2 ohms will have lower output device resistances
than a different amplifier rated at 500 W into 8 ohms.

This isn't a good assumption to make. In fact, the two could even be
the same amplifier!

A typical amplifier rated at 500W into 8 ohms should also be rated 2000W
into 2 ohms, and therefore ought to have _lower_ device resistance than
an amplifier rated at 500W into 2 ohms.

Unfortunately many don't. Which is why a lot of amplifiers rated 500W
into 8 ohms are only rated 1500W into 2 ohms... where is that other 500W
going? --scott


HEAT...

For raw power, one of the new things coming out of the chip manufacturers
labs is PWM, or Pulse Width Modulation so that the output transistors are
either fully on or fully off.


The other approach is called Class G, where the power supply voltage is
modulated to meet the current needs.

As others have noted, both Class G and PWM technologies go back at least 20
years and have very mature examples on the market right now, with
more-or-less competitive performance and reliability, selling for
competitive prices.


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liquidator wrote:

There are, and have been for some time, amps in the kilowatt and higher
range using PWM. Your info is 20 years old.

Raw power yes, but I wouldn't call it audiophile quality.
I know about those and they might make for good football stadium amps
but fidelity doesn't count there.
Bill Baka
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Arny Krueger wrote:
The other approach is called Class G, where the power supply voltage is
modulated to meet the current needs.

As others have noted, both Class G and PWM technologies go back at least 20
years and have very mature examples on the market right now, with
more-or-less competitive performance and reliability, selling for
competitive prices.


I would go with the Class G for pure audio quality and not just
efficiency. Of course then the power supply has to be a switcher, or PWM.
Bill Baka


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Bill bbaka@c-o-m-c-a-s-t-dot-n-e-t wrote:

For raw power, one of the new things coming out of the chip
manufacturers labs is PWM, or Pulse Width Modulation so that the output
transistors are either fully on or fully off. So far they have it
working with low power audio and are thinking of making it standard in
cell phones to save even more power. No fidelity there though.
I did a project with it a few years back for motor control with an
output bandwidth up to 1KHz and distortion was not an issue there but I
was putting out about a hundred watts with a 50KHz pulse frequency and
very little transistor heat. I don't know if any manufacturers of high
power audio will try to go that way for a while, but I have heard it
mentioned for consumer audio equipment up to about 50 watts.
Right now, it is a wait and see.


Actually, there are lots and lots of high power "Class D" switching
amps. The Crown K2 was probably the first one that became popular but
now there are a huge number of them on the market. For the most part
I have not been impressed with the sound quality of any of them, but they
DO produce a huge amount of power in a couple rack spaces, and there are
certainly applications that can benefit from that.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Default Help wiring speakers

Scott Dorsey wrote:
Bill bbaka@c-o-m-c-a-s-t-dot-n-e-t wrote:
For raw power, one of the new things coming out of the chip
manufacturers labs is PWM, or Pulse Width Modulation so that the output
transistors are either fully on or fully off. So far they have it
working with low power audio and are thinking of making it standard in
cell phones to save even more power. No fidelity there though.
I did a project with it a few years back for motor control with an
output bandwidth up to 1KHz and distortion was not an issue there but I
was putting out about a hundred watts with a 50KHz pulse frequency and
very little transistor heat. I don't know if any manufacturers of high
power audio will try to go that way for a while, but I have heard it
mentioned for consumer audio equipment up to about 50 watts.
Right now, it is a wait and see.


Actually, there are lots and lots of high power "Class D" switching
amps. The Crown K2 was probably the first one that became popular but
now there are a huge number of them on the market. For the most part
I have not been impressed with the sound quality of any of them, but they
DO produce a huge amount of power in a couple rack spaces, and there are
certainly applications that can benefit from that.
--scott


I see you get my point, either power or fidelity, but rarely both. The
Class D amps can be made higher fidelity but that requires better
feedback, higher switching frequencies (less efficient), or bigger
smoothing inductors (bigger and more expensive).
Economics is driving things, and not always in the desired direction.
Bill Baka
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liquidator liquidator is offline
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"Bill" wrote in message
. ..
liquidator wrote:

There are, and have been for some time, amps in the kilowatt and higher
range using PWM. Your info is 20 years old.

Raw power yes, but I wouldn't call it audiophile quality.
I know about those and they might make for good football stadium amps
but fidelity doesn't count there.
Bill Baka


pure bull.

http://www.digiamps.com/

http://www.cadaudio.dk/hifiamplifiers.htm



--
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Bill Bill is offline
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Default Help wiring speakers

liquidator wrote:
"Bill" wrote in message
. ..
liquidator wrote:
There are, and have been for some time, amps in the kilowatt and higher
range using PWM. Your info is 20 years old.

Raw power yes, but I wouldn't call it audiophile quality.
I know about those and they might make for good football stadium amps
but fidelity doesn't count there.
Bill Baka


pure bull.

http://www.digiamps.com/

http://www.cadaudio.dk/hifiamplifiers.htm



It wasn't "Pure bull" that long ago. I visited both sites and while
neither mentioned their actual clock frequency, Cadaudio did mention
that they have now gotten better fidelity by raising their PWM clock.
The clock and inductors needed used to be the limiting factor, and the
cost. The THD at 1KHz of 0.02% does look good (now) but that does
increase more with frequency than with a linear amp. As higher speed
transistors come out PWM amps will get better. Both of these
manufacturers are pretty obviously for the high power do it your self
audiophile since they are open frame units. I doubt you will see them on
sale at Wal-mart any time soon.
They both appear to be Danish so that explains why I haven't seen
anything like that on this side of the pond.

Sometimes I have to provoke someone who knows about something to post a
link to the group, thinking they are calling my bluff, but in fact
providing information I don't have time to chase.

Digiamps seems to have some very low prices, while Cadaudio is more what
I would expect at about a kilobuck.

Provoking a response usually works, so I have to thank Liquidator for
providing us all with 2 more bookmarks in the audio arena.

It's just the way I post.
Bill Baka
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liquidator liquidator is offline
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"Bill" wrote in message
t...
liquidator wrote:
"Bill" wrote in message
. ..
liquidator wrote:
There are, and have been for some time, amps in the kilowatt and

higher
range using PWM. Your info is 20 years old.

Raw power yes, but I wouldn't call it audiophile quality.
I know about those and they might make for good football stadium amps
but fidelity doesn't count there.
Bill Baka


pure bull.

http://www.digiamps.com/

http://www.cadaudio.dk/hifiamplifiers.htm



It wasn't "Pure bull" that long ago. I visited both sites and while
neither mentioned their actual clock frequency, Cadaudio did mention
that they have now gotten better fidelity by raising their PWM clock.
The clock and inductors needed used to be the limiting factor, and the
cost. The THD at 1KHz of 0.02% does look good (now) but that does
increase more with frequency than with a linear amp. As higher speed
transistors come out PWM amps will get better. Both of these
manufacturers are pretty obviously for the high power do it your self
audiophile since they are open frame units. I doubt you will see them on
sale at Wal-mart any time soon.
They both appear to be Danish so that explains why I haven't seen
anything like that on this side of the pond.

Sometimes I have to provoke someone who knows about something to post a
link to the group, thinking they are calling my bluff, but in fact
providing information I don't have time to chase.

Digiamps seems to have some very low prices, while Cadaudio is more what
I would expect at about a kilobuck.

Provoking a response usually works, so I have to thank Liquidator for
providing us all with 2 more bookmarks in the audio arena.

It's just the way I post.
Bill Baka



PWM is generally more advanced in Europe.

The only American manufacturer I know really pursuing it is Tripath.

There is nothing inherently worse about it,just many businesses look at new
technologies as a way to make things cheaper instead of better.




--
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Default Help wiring speakers

liquidator wrote:
"Bill" wrote in message
t...
It's just the way I post.
Bill Baka



PWM is generally more advanced in Europe.

The only American manufacturer I know really pursuing it is Tripath.

There is nothing inherently worse about it,just many businesses look at new
technologies as a way to make things cheaper instead of better.


Europe does have a tendency to do things for the sake of technology and
not just the dollar return to the venture capital group. I wish America
were more like that. Some of the best audio (and video) equipment I have
seen has come from a single engineer or group that were so sick of being
told to do things on the cheap that they started their own companies.
Your statement about "cheaper instead of better" is right on the mark
here in the states.
Bill Baka
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Middle C Middle C is offline
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"Lord Vader" wrote in message
oups.com...
Thanks for the Reply.. What I tryin' to do is upgrade the stock (four
16 Ohms) 10 "speakers w/ better speakers w/ lots of low end. I haven't
seen any 16 Ohms replacement most or all of them are 8 Ohms.. You said
I have to get 16 or 4 Ohms enable to use the 4/16 Mono and 8 Stero Ohm
switch? If I go with four 8 Ohms, then I need to replace the input
switch thats just 8 Ohms? Thanks for the Help!!

Oci-One Kanubi wrote:


In that case, you may want to consider getting a whole new cabinet. The
cabinet has as much to do with getting that low end tone as the speakers.
Bass speakers need specific cabinet volume and porting to operate at there
optimum levels. Putting bass speakers into your 'guitar' cabinet will not
likely produce very good results.

But to answer your question, you would want to bypass the ohm switching
feature of the cabnet. You best bet would be to use 8ohm speakers, and net
a total 8 ohm load.

MIddel C















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