(dangling entity) wrote in message . com...
Is there some practical way to do this by doing something funky in the
feedback loop or something? Would there be considerable downsides wrt
the operation of the amplifier itself? Excessive thermal dissipation
in the amplifier output stages, for instance? Do SS amplifiers like
this already exist (for one reason or another), or would this be
relatively virgin territory?


Are you looking for something to drive a novel design of low audio (or
sub-audio) frequency electrical current to air pressure transducer,
perhaps novel enough that conventional terms such as speaker and
subwoofer are inadequate? If it's something you may seek a patent
for, and therefore wish to withhold details, can you at least reveal
input impedence and power requirements? Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?

(unitron) wrote in message . com...
(dangling entity) wrote in message . com...
Is there some practical way to do this by doing something funky in the
feedback loop or something? Would there be considerable downsides wrt
the operation of the amplifier itself? Excessive thermal dissipation
in the amplifier output stages, for instance? Do SS amplifiers like
this already exist (for one reason or another), or would this be
relatively virgin territory?


Are you looking for something to drive a novel design of low audio (or
sub-audio) frequency electrical current to air pressure transducer,
perhaps novel enough that conventional terms such as speaker and
subwoofer are inadequate? If it's something you may seek a patent
for, and therefore wish to withhold details, can you at least reveal
input impedence and power requirements? Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?

Fiddling with the series resistance affects the drivers Qts value (via
Qes). The requirements on the Qts value can vary between designs. So,
there is actually no universally optimal Qts value, and no universally
optimal series resistance (=damping factor) for a loudspeaker DRIVER.
For the engineer, the series resistance can be seen as an interesting
opportunity to change the Qts value.

To make use of this opportunity, the speaker system would have to be
designed *together* with the series resistance, and would typically
include a built-in amplifier. Positive resistor values could be
realised with an ordinary resistor, but in order to avoid power loss,
it can be realised with negative feedback of the driver current.
Negative resistances can be realised with positive feedback of the
driver current.

Commercially available non-amplified speaker systems are however
almost always designed for a near-zero series impedance, probably
because most amplifiers have a near-zero output impedance.

BTW, having understood these effects it appears clear that the value
of extremely low cable resistances and/or extremely high damping
factors is questionable, IMO. As an example, 100 milliohm series
resistance change would correspond to the resistance change due to a
temperature raise of about 7 degrees celcius of the (4 ohm) voice
coil.

Am I drifting off the topic...? :-)

(unitron) wrote in message . com...
(dangling entity) wrote in message . com...
Is there some practical way to do this by doing something funky in the
feedback loop or something? Would there be considerable downsides wrt
the operation of the amplifier itself? Excessive thermal dissipation
in the amplifier output stages, for instance? Do SS amplifiers like
this already exist (for one reason or another), or would this be
relatively virgin territory?


Are you looking for something to drive a novel design of low audio (or
sub-audio) frequency electrical current to air pressure transducer,
perhaps novel enough that conventional terms such as speaker and
subwoofer are inadequate? If it's something you may seek a patent
for, and therefore wish to withhold details, can you at least reveal
input impedence and power requirements? Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?

Fiddling with the series resistance affects the drivers Qts value (via
Qes). The requirements on the Qts value can vary between designs. So,
there is actually no universally optimal Qts value, and no universally
optimal series resistance (=damping factor) for a loudspeaker DRIVER.
For the engineer, the series resistance can be seen as an interesting
opportunity to change the Qts value.

To make use of this opportunity, the speaker system would have to be
designed *together* with the series resistance, and would typically
include a built-in amplifier. Positive resistor values could be
realised with an ordinary resistor, but in order to avoid power loss,
it can be realised with negative feedback of the driver current.
Negative resistances can be realised with positive feedback of the
driver current.

Commercially available non-amplified speaker systems are however
almost always designed for a near-zero series impedance, probably
because most amplifiers have a near-zero output impedance.

BTW, having understood these effects it appears clear that the value
of extremely low cable resistances and/or extremely high damping
factors is questionable, IMO. As an example, 100 milliohm series
resistance change would correspond to the resistance change due to a
temperature raise of about 7 degrees celcius of the (4 ohm) voice
coil.

Am I drifting off the topic...? :-)

(unitron) wrote in message . com...
(dangling entity) wrote in message . com...
Is there some practical way to do this by doing something funky in the
feedback loop or something? Would there be considerable downsides wrt
the operation of the amplifier itself? Excessive thermal dissipation
in the amplifier output stages, for instance? Do SS amplifiers like
this already exist (for one reason or another), or would this be
relatively virgin territory?


Are you looking for something to drive a novel design of low audio (or
sub-audio) frequency electrical current to air pressure transducer,
perhaps novel enough that conventional terms such as speaker and
subwoofer are inadequate? If it's something you may seek a patent
for, and therefore wish to withhold details, can you at least reveal
input impedence and power requirements? Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?

Fiddling with the series resistance affects the drivers Qts value (via
Qes). The requirements on the Qts value can vary between designs. So,
there is actually no universally optimal Qts value, and no universally
optimal series resistance (=damping factor) for a loudspeaker DRIVER.
For the engineer, the series resistance can be seen as an interesting
opportunity to change the Qts value.

To make use of this opportunity, the speaker system would have to be
designed *together* with the series resistance, and would typically
include a built-in amplifier. Positive resistor values could be
realised with an ordinary resistor, but in order to avoid power loss,
it can be realised with negative feedback of the driver current.
Negative resistances can be realised with positive feedback of the
driver current.

Commercially available non-amplified speaker systems are however
almost always designed for a near-zero series impedance, probably
because most amplifiers have a near-zero output impedance.

BTW, having understood these effects it appears clear that the value
of extremely low cable resistances and/or extremely high damping
factors is questionable, IMO. As an example, 100 milliohm series
resistance change would correspond to the resistance change due to a
temperature raise of about 7 degrees celcius of the (4 ohm) voice
coil.

Am I drifting off the topic...? :-)

(unitron) wrote in message . com...
(dangling entity) wrote in message . com...
Is there some practical way to do this by doing something funky in the
feedback loop or something? Would there be considerable downsides wrt
the operation of the amplifier itself? Excessive thermal dissipation
in the amplifier output stages, for instance? Do SS amplifiers like
this already exist (for one reason or another), or would this be
relatively virgin territory?


Are you looking for something to drive a novel design of low audio (or
sub-audio) frequency electrical current to air pressure transducer,
perhaps novel enough that conventional terms such as speaker and
subwoofer are inadequate? If it's something you may seek a patent
for, and therefore wish to withhold details, can you at least reveal
input impedence and power requirements? Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?

Fiddling with the series resistance affects the drivers Qts value (via
Qes). The requirements on the Qts value can vary between designs. So,
there is actually no universally optimal Qts value, and no universally
optimal series resistance (=damping factor) for a loudspeaker DRIVER.
For the engineer, the series resistance can be seen as an interesting
opportunity to change the Qts value.

To make use of this opportunity, the speaker system would have to be
designed *together* with the series resistance, and would typically
include a built-in amplifier. Positive resistor values could be
realised with an ordinary resistor, but in order to avoid power loss,
it can be realised with negative feedback of the driver current.
Negative resistances can be realised with positive feedback of the
driver current.

Commercially available non-amplified speaker systems are however
almost always designed for a near-zero series impedance, probably
because most amplifiers have a near-zero output impedance.

BTW, having understood these effects it appears clear that the value
of extremely low cable resistances and/or extremely high damping
factors is questionable, IMO. As an example, 100 milliohm series
resistance change would correspond to the resistance change due to a
temperature raise of about 7 degrees celcius of the (4 ohm) voice
coil.

Am I drifting off the topic...? :-)

I'd say svante is pretty much riding the same wavelength I am, in
requesting info on such an odd setup. Negative current feedback, but
watchout for instability, eh? Interesting! So would such a
configuration bring about other barriers to high power output (as in
subwoofer amp sort of watts), relative to conventional low Z-out
amplifiers?

I'd say svante is pretty much riding the same wavelength I am, in
requesting info on such an odd setup. Negative current feedback, but
watchout for instability, eh? Interesting! So would such a
configuration bring about other barriers to high power output (as in
subwoofer amp sort of watts), relative to conventional low Z-out
amplifiers?

I'd say svante is pretty much riding the same wavelength I am, in
requesting info on such an odd setup. Negative current feedback, but
watchout for instability, eh? Interesting! So would such a
configuration bring about other barriers to high power output (as in
subwoofer amp sort of watts), relative to conventional low Z-out
amplifiers?

I'd say svante is pretty much riding the same wavelength I am, in
requesting info on such an odd setup. Negative current feedback, but
watchout for instability, eh? Interesting! So would such a
configuration bring about other barriers to high power output (as in
subwoofer amp sort of watts), relative to conventional low Z-out
amplifiers?

(Svante) wrote in message . com...
(unitron) wrote in message . com...

---SNIP!---
Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?


--and then Svante wrote a bunch of smart stuff I could only sort of
grasp, followed by--


Am I drifting off the topic...? :-)

I knew I shouldn't have mentioned religion, I mean, damping factor :-)

Seriously, my question was mostly about why someone would want an amp
intended to drive a speaker to have a high output impedence when the
general trend is to build 'em so that they won't let the magic smoke
out when someone parallels a second speaker on the output.

(Svante) wrote in message . com...
(unitron) wrote in message . com...

---SNIP!---
Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?


--and then Svante wrote a bunch of smart stuff I could only sort of
grasp, followed by--


Am I drifting off the topic...? :-)

I knew I shouldn't have mentioned religion, I mean, damping factor :-)

Seriously, my question was mostly about why someone would want an amp
intended to drive a speaker to have a high output impedence when the
general trend is to build 'em so that they won't let the magic smoke
out when someone parallels a second speaker on the output.

(Svante) wrote in message . com...
(unitron) wrote in message . com...

---SNIP!---
Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?


--and then Svante wrote a bunch of smart stuff I could only sort of
grasp, followed by--


Am I drifting off the topic...? :-)

I knew I shouldn't have mentioned religion, I mean, damping factor :-)

Seriously, my question was mostly about why someone would want an amp
intended to drive a speaker to have a high output impedence when the
general trend is to build 'em so that they won't let the magic smoke
out when someone parallels a second speaker on the output.

(Svante) wrote in message . com...
(unitron) wrote in message . com...

---SNIP!---
Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?


--and then Svante wrote a bunch of smart stuff I could only sort of
grasp, followed by--


Am I drifting off the topic...? :-)

I knew I shouldn't have mentioned religion, I mean, damping factor :-)

Seriously, my question was mostly about why someone would want an amp
intended to drive a speaker to have a high output impedence when the
general trend is to build 'em so that they won't let the magic smoke
out when someone parallels a second speaker on the output.

(dangling entity) wrote in message . com...
I'd say svante is pretty much riding the same wavelength I am, in
requesting info on such an odd setup. Negative current feedback, but
watchout for instability, eh? Interesting! So would such a
configuration bring about other barriers to high power output (as in
subwoofer amp sort of watts), relative to conventional low Z-out
amplifiers?

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies. The main effect would as I said be an
alteration of Qts and a lowered efficiency if the resistor is passive.
In our loudspeaker laboration we actually use a series resistance to
tune the Qts of a driver. The lab instructions
http://www.speech.kth.se/~svante/elak/htlab.pdf
are in swedish, sorry, but you can find the equation for calculating
the series resistance on page 14, equation 11. Q'ts is the Qts you
want, Qts is what you have. It's a horrible equation and students
*never* get it right the first time, so check it carefully before
relying on your results. All variables should be entered in SI units,
ie m3, m2, m/s etc.

HTH
/Svante

(dangling entity) wrote in message . com...
I'd say svante is pretty much riding the same wavelength I am, in
requesting info on such an odd setup. Negative current feedback, but
watchout for instability, eh? Interesting! So would such a
configuration bring about other barriers to high power output (as in
subwoofer amp sort of watts), relative to conventional low Z-out
amplifiers?

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies. The main effect would as I said be an
alteration of Qts and a lowered efficiency if the resistor is passive.
In our loudspeaker laboration we actually use a series resistance to
tune the Qts of a driver. The lab instructions
http://www.speech.kth.se/~svante/elak/htlab.pdf
are in swedish, sorry, but you can find the equation for calculating
the series resistance on page 14, equation 11. Q'ts is the Qts you
want, Qts is what you have. It's a horrible equation and students
*never* get it right the first time, so check it carefully before
relying on your results. All variables should be entered in SI units,
ie m3, m2, m/s etc.

HTH
/Svante

(dangling entity) wrote in message . com...
I'd say svante is pretty much riding the same wavelength I am, in
requesting info on such an odd setup. Negative current feedback, but
watchout for instability, eh? Interesting! So would such a
configuration bring about other barriers to high power output (as in
subwoofer amp sort of watts), relative to conventional low Z-out
amplifiers?

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies. The main effect would as I said be an
alteration of Qts and a lowered efficiency if the resistor is passive.
In our loudspeaker laboration we actually use a series resistance to
tune the Qts of a driver. The lab instructions
http://www.speech.kth.se/~svante/elak/htlab.pdf
are in swedish, sorry, but you can find the equation for calculating
the series resistance on page 14, equation 11. Q'ts is the Qts you
want, Qts is what you have. It's a horrible equation and students
*never* get it right the first time, so check it carefully before
relying on your results. All variables should be entered in SI units,
ie m3, m2, m/s etc.

HTH
/Svante

(dangling entity) wrote in message . com...
I'd say svante is pretty much riding the same wavelength I am, in
requesting info on such an odd setup. Negative current feedback, but
watchout for instability, eh? Interesting! So would such a
configuration bring about other barriers to high power output (as in
subwoofer amp sort of watts), relative to conventional low Z-out
amplifiers?

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies. The main effect would as I said be an
alteration of Qts and a lowered efficiency if the resistor is passive.
In our loudspeaker laboration we actually use a series resistance to
tune the Qts of a driver. The lab instructions
http://www.speech.kth.se/~svante/elak/htlab.pdf
are in swedish, sorry, but you can find the equation for calculating
the series resistance on page 14, equation 11. Q'ts is the Qts you
want, Qts is what you have. It's a horrible equation and students
*never* get it right the first time, so check it carefully before
relying on your results. All variables should be entered in SI units,
ie m3, m2, m/s etc.

HTH
/Svante

(unitron) wrote in message . com...
(Svante) wrote in message . com...
(unitron) wrote in message . com...

---SNIP!---
Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?


--and then Svante wrote a bunch of smart stuff I could only sort of
grasp, followed by--


Am I drifting off the topic...? :-)

I knew I shouldn't have mentioned religion, I mean, damping factor :-)

Seriously, my question was mostly about why someone would want an amp
intended to drive a speaker to have a high output impedence when the
general trend is to build 'em so that they won't let the magic smoke
out when someone parallels a second speaker on the output.

In the normal case it is a good idea to have a *reasonably* low output
impedance, firstly because most speaker systems are designed for such
an amplifier, secondly for the thing you mention about paralleling
more than one speaker.
The non-zero output impedance would have to be designed knowing the
loudspeaker that is connected to it. Such a design should be
integrated in the loudspeaker system.

(unitron) wrote in message . com...
(Svante) wrote in message . com...
(unitron) wrote in message . com...

---SNIP!---
Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?


--and then Svante wrote a bunch of smart stuff I could only sort of
grasp, followed by--


Am I drifting off the topic...? :-)

I knew I shouldn't have mentioned religion, I mean, damping factor :-)

Seriously, my question was mostly about why someone would want an amp
intended to drive a speaker to have a high output impedence when the
general trend is to build 'em so that they won't let the magic smoke
out when someone parallels a second speaker on the output.

In the normal case it is a good idea to have a *reasonably* low output
impedance, firstly because most speaker systems are designed for such
an amplifier, secondly for the thing you mention about paralleling
more than one speaker.
The non-zero output impedance would have to be designed knowing the
loudspeaker that is connected to it. Such a design should be
integrated in the loudspeaker system.

(unitron) wrote in message . com...
(Svante) wrote in message . com...
(unitron) wrote in message . com...

---SNIP!---
Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?


--and then Svante wrote a bunch of smart stuff I could only sort of
grasp, followed by--


Am I drifting off the topic...? :-)

I knew I shouldn't have mentioned religion, I mean, damping factor :-)

Seriously, my question was mostly about why someone would want an amp
intended to drive a speaker to have a high output impedence when the
general trend is to build 'em so that they won't let the magic smoke
out when someone parallels a second speaker on the output.

In the normal case it is a good idea to have a *reasonably* low output
impedance, firstly because most speaker systems are designed for such
an amplifier, secondly for the thing you mention about paralleling
more than one speaker.
The non-zero output impedance would have to be designed knowing the
loudspeaker that is connected to it. Such a design should be
integrated in the loudspeaker system.

(unitron) wrote in message . com...
(Svante) wrote in message . com...
(unitron) wrote in message . com...

---SNIP!---
Ordinarily wouldn't lower amp
output impedence be better from a standpoint of damping factor and not
being subjected to too low of a load impedence (i.e., too great a
load, drawing too much current)?


--and then Svante wrote a bunch of smart stuff I could only sort of
grasp, followed by--


Am I drifting off the topic...? :-)

I knew I shouldn't have mentioned religion, I mean, damping factor :-)

Seriously, my question was mostly about why someone would want an amp
intended to drive a speaker to have a high output impedence when the
general trend is to build 'em so that they won't let the magic smoke
out when someone parallels a second speaker on the output.

In the normal case it is a good idea to have a *reasonably* low output
impedance, firstly because most speaker systems are designed for such
an amplifier, secondly for the thing you mention about paralleling
more than one speaker.
The non-zero output impedance would have to be designed knowing the
loudspeaker that is connected to it. Such a design should be
integrated in the loudspeaker system.

(Svante) wrote in message . com...

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies.

The meaning I intended was really asking about the *amplifier*. Would
the amplifier experience difficulty with this new feedback setup in
delivering rated output, overheating, driving the targeted speaker at
frequencies where the impedance hits the mins, etc.? Basically, I'm
asking if this feedback scheme places additional stresses on the
amplifier such that it doesn't perform as well as it did when it was a
plain ole low-Z amplifier?

(Svante) wrote in message . com...

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies.

The meaning I intended was really asking about the *amplifier*. Would
the amplifier experience difficulty with this new feedback setup in
delivering rated output, overheating, driving the targeted speaker at
frequencies where the impedance hits the mins, etc.? Basically, I'm
asking if this feedback scheme places additional stresses on the
amplifier such that it doesn't perform as well as it did when it was a
plain ole low-Z amplifier?

(Svante) wrote in message . com...

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies.

The meaning I intended was really asking about the *amplifier*. Would
the amplifier experience difficulty with this new feedback setup in
delivering rated output, overheating, driving the targeted speaker at
frequencies where the impedance hits the mins, etc.? Basically, I'm
asking if this feedback scheme places additional stresses on the
amplifier such that it doesn't perform as well as it did when it was a
plain ole low-Z amplifier?

(Svante) wrote in message . com...

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies.

The meaning I intended was really asking about the *amplifier*. Would
the amplifier experience difficulty with this new feedback setup in
delivering rated output, overheating, driving the targeted speaker at
frequencies where the impedance hits the mins, etc.? Basically, I'm
asking if this feedback scheme places additional stresses on the
amplifier such that it doesn't perform as well as it did when it was a
plain ole low-Z amplifier?

(dangling entity) wrote in message . com...
(Svante) wrote in message . com...

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies.

The meaning I intended was really asking about the *amplifier*. Would
the amplifier experience difficulty with this new feedback setup in
delivering rated output, overheating, driving the targeted speaker at
frequencies where the impedance hits the mins, etc.? Basically, I'm
asking if this feedback scheme places additional stresses on the
amplifier such that it doesn't perform as well as it did when it was a
plain ole low-Z amplifier?

Negative and positive current feedback has been used at least since
the sixties, so I'd say it is safe to say that it is practically
possible to use this scheme. As always with feedback, there is the
risk of self-oscillation, which has to be taken care of. In the case
with a single electrodynamic driver connected to such an amp, there
*should* not be much of a problem, since the impedance of the voice
coil is high for HF, resulting in a low current and low feedback at
HF.
If you are new to it, do some experimenting with inexpensive parts
first, to be on the safe side. :-)

(dangling entity) wrote in message . com...
(Svante) wrote in message . com...

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies.

The meaning I intended was really asking about the *amplifier*. Would
the amplifier experience difficulty with this new feedback setup in
delivering rated output, overheating, driving the targeted speaker at
frequencies where the impedance hits the mins, etc.? Basically, I'm
asking if this feedback scheme places additional stresses on the
amplifier such that it doesn't perform as well as it did when it was a
plain ole low-Z amplifier?

Negative and positive current feedback has been used at least since
the sixties, so I'd say it is safe to say that it is practically
possible to use this scheme. As always with feedback, there is the
risk of self-oscillation, which has to be taken care of. In the case
with a single electrodynamic driver connected to such an amp, there
*should* not be much of a problem, since the impedance of the voice
coil is high for HF, resulting in a low current and low feedback at
HF.
If you are new to it, do some experimenting with inexpensive parts
first, to be on the safe side. :-)

(dangling entity) wrote in message . com...
(Svante) wrote in message . com...

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies.

The meaning I intended was really asking about the *amplifier*. Would
the amplifier experience difficulty with this new feedback setup in
delivering rated output, overheating, driving the targeted speaker at
frequencies where the impedance hits the mins, etc.? Basically, I'm
asking if this feedback scheme places additional stresses on the
amplifier such that it doesn't perform as well as it did when it was a
plain ole low-Z amplifier?

Negative and positive current feedback has been used at least since
the sixties, so I'd say it is safe to say that it is practically
possible to use this scheme. As always with feedback, there is the
risk of self-oscillation, which has to be taken care of. In the case
with a single electrodynamic driver connected to such an amp, there
*should* not be much of a problem, since the impedance of the voice
coil is high for HF, resulting in a low current and low feedback at
HF.
If you are new to it, do some experimenting with inexpensive parts
first, to be on the safe side. :-)

(dangling entity) wrote in message . com...
(Svante) wrote in message . com...

Let's see if I understand your question correctly; the maximum output
would normally not be affected, since it is determined by Xmax of the
driver for low frequencies.

The meaning I intended was really asking about the *amplifier*. Would
the amplifier experience difficulty with this new feedback setup in
delivering rated output, overheating, driving the targeted speaker at
frequencies where the impedance hits the mins, etc.? Basically, I'm
asking if this feedback scheme places additional stresses on the
amplifier such that it doesn't perform as well as it did when it was a
plain ole low-Z amplifier?

Negative and positive current feedback has been used at least since
the sixties, so I'd say it is safe to say that it is practically
possible to use this scheme. As always with feedback, there is the
risk of self-oscillation, which has to be taken care of. In the case
with a single electrodynamic driver connected to such an amp, there
*should* not be much of a problem, since the impedance of the voice
coil is high for HF, resulting in a low current and low feedback at
HF.
If you are new to it, do some experimenting with inexpensive parts
first, to be on the safe side. :-)