Chris Berry wrote:

.. The cap is there to protect the compression driver from
any DC offset as the power amp may have - or develop when
failing - on the output. An active cross-over on the input
side of the power amp does not make any difference in that
context. In the context of instrument sound ... i. e. one
where a theoretical minor midrange summing unlinearity is
irrelevant ... adding that capacitor can be done so as to
provide the required x-over slope.

Sorry - I meant 18dB. AFAICS the capacitors in the high pass passive network
should provide the necessary isolation.

What high pass passive network? - we're talking about using an active
network in front of the power amp input and about supplementing it with
a cap in series with the compression driver. If I get you right you have
a third order highpass in the preamp you use, in which case adding a
series cap CAN be done with the aim of increasing the roll-off to 24 dB
pr. octave, it either has to augment the x-over that is used or to be
acting so far below that it does not cause too much effect (phase
change) at the x-over point.

Please understand when such apparent nagging happens that it is about
keeping it relevant also for those that just have similar problems, a
usenet follow up is hardly ever written with just the questionee in
mind.

[dimensioning x-over coils]

It is not just about cross-section but also about lenght of copper, i.
e. also about the resistive loss and about how much is acceptable in the
context of the design.

Very true. Is there any way of calculating the power requirements though?

Hmmm .... I'll leave this to other people. It is probably somewhat less
simple than looking at its restistance vs. the current through it.

Sorry, I don't want to bother with checking what cap to use in series
with the compression driver for the result of using the ashley to become
18 dB pr. octave.

/* note to new readers: the ashley instrument preamps internal */
/* x-over is reported as being 18 dB pr. octave */

I don't think it would be useful so no worries. You've been very helpful and
your advice is very much appreciated. Certainly opened up some avenues of
thought that are worth experimenting with!

If you want to take the gamble of not using the recommended protection
cap, then it is just that, a gamble and your very own. From your
description of the poweramp the risk is probably not large, just
understand that it is a risk of the order of magnitude of whatever a
repair kit costs. Back in the very old days when I was involved with a
rental company here in Copenhagen the owner of the shop decided against
using any protection caps because they in his opinion were too
detrimental to the sound. He felt the risk was worth it and the
compression drivers that did die had other kinds of overload as cause of
death. It is however the consensus here in aapls that not using
compression driver protection caps constitutes malpractice.

I'm contenplating using another inductor in series with one of the drivers -
a bit of calculation and I'll test how it sounds in a moment.

I hope you don't see this as a waste of time because I have posted qhestions
about crossovers elsewhere but this is the only forum that actually has the
knowledge on the subject in real world applications that I've found.

There is also rec.audio.tech, I have added a crosspost to them in case
the good people there want to supplement.

I realise that you folks deal primarily with bigger issues but it's really
nice that you can spend the time to help sort out something small.

A cross-over is a cross-over is a cross-over, but concerns may be more
stringent for front of house, and I did read it as being about voice
projection, dual 10" units and a small midrange horn seemed to point in
that general direction.

The design strategy is however the same and there is still the Behringer
active cross-overs to consider depending on just what functionality your
still only vaguely defined equipment has to offer.

I haven't tried using them, but based on specs something like the

http://www.behringer.com/02_products...X2310&lang=ENG

may or may not do just fine. It is simply meant to constitute an example
of the budget friendly choices out there. List price at
http://www.aage.dk is a humble dkk 995 including local v.a.t. ....

On http://www.ashly.com/powercard they say that:

"The XR-1 Three-Way Crossover features 24dB/octave filters,
"20 Hz Low-cut filter, 360 degree phase control, internally
"adjustable frequency, CD Horn EQ switching, auxiliary outputs,
"and a mode switch for biamped or low only configuration.

An obvious question: just what ashly product is it that you _are_ using?

Thanks again...

Oh ... you're welcome ...

cb

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

"Peter Larsen" wrote in message
...

Sorry - I meant 18dB. AFAICS the capacitors in the high pass passive
network
should provide the necessary isolation.

What high pass passive network? - we're talking about using an active
network in front of the power amp input and about supplementing it with
a cap in series with the compression driver. If I get you right you have
a third order highpass in the preamp you use, in which case adding a
series cap CAN be done with the aim of increasing the roll-off to 24 dB
pr. octave, it either has to augment the x-over that is used or to be
acting so far below that it does not cause too much effect (phase
change) at the x-over point.

OKOKOKOKOK.....
Here's the confusion: The ashly instrument preamplifier (Model BP-41 has a
built in 12dB/octave active crossover.)
The protection I'm talking about here is an 18dB passive crossover - at
1700Hz (high pass) at the moment (it's being modified all the time) which
I'm using to protect the compression driver for which 12dB 1600Hz is the
recomended min spec.
Here I believe there is no further necessary dc protection or components
(say except an Lpad which is there and a overload protection PTC).


Please understand when such apparent nagging happens that it is about
keeping it relevant also for those that just have similar problems, a
usenet follow up is hardly ever written with just the questionee in
mind.

Sure Peter, I understand very well. It's out of courtesy (something not
always found on usenet) that I respond in this way to what you describe as
nagging. Respect is due and you are helping me a lot already so there's no
reason to start any kind of flame war. I am grateful.


[dimensioning x-over coils]

It is not just about cross-section but also about lenght of copper, i.
e. also about the resistive loss and about how much is acceptable in
the
context of the design.

Very true. Is there any way of calculating the power requirements
though?

Hmmm .... I'll leave this to other people. It is probably somewhat less
simple than looking at its restistance vs. the current through it.

Sorry, I don't want to bother with checking what cap to use in series
with the compression driver for the result of using the ashley to
become
18 dB pr. octave.

/* note to new readers: the ashley instrument preamps internal */
/* x-over is reported as being 18 dB pr. octave */

Actually 12dB/octave.
/* Note to new readers (as this is cross posted) that the 12dB works well on
the compression driver but on the 10" speakers the result was unsatisfactory
with midrange peaks being present.


I don't think it would be useful so no worries. You've been very helpful
and
your advice is very much appreciated. Certainly opened up some avenues
of
thought that are worth experimenting with!

If you want to take the gamble of not using the recommended protection
cap, then it is just that, a gamble and your very own. From your
description of the poweramp the risk is probably not large, just
understand that it is a risk of the order of magnitude of whatever a
repair kit costs. Back in the very old days when I was involved with a
rental company here in Copenhagen the owner of the shop decided against
using any protection caps because they in his opinion were too
detrimental to the sound. He felt the risk was worth it and the
compression drivers that did die had other kinds of overload as cause of
death. It is however the consensus here in aapls that not using
compression driver protection caps constitutes malpractice.

See above - I think we're talking cross purposes here. the 18dB High pass
being used is passive...
I do trust and understand where that experience comes from.


I'm contenplating using another inductor in series with one of the
drivers -
a bit of calculation and I'll test how it sounds in a moment.

I hope you don't see this as a waste of time because I have posted
qhestions
about crossovers elsewhere but this is the only forum that actually has
the
knowledge on the subject in real world applications that I've found.

There is also rec.audio.tech, I have added a crosspost to them in case
the good people there want to supplement.

Thanks.


I realise that you folks deal primarily with bigger issues but it's
really
nice that you can spend the time to help sort out something small.

A cross-over is a cross-over is a cross-over, but concerns may be more
stringent for front of house, and I did read it as being about voice
projection, dual 10" units and a small midrange horn seemed to point in
that general direction.

Sorry about that. the good news is what I've tried already does seem to
confirm your assumptions... It actually has a fairly nice response from
40-17kHz...


The design strategy is however the same and there is still the Behringer
active cross-overs to consider depending on just what functionality your
still only vaguely defined equipment has to offer.

I haven't tried using them, but based on specs something like the

http://www.behringer.com/02_products...X2310&lang=ENG

may or may not do just fine. It is simply meant to constitute an example
of the budget friendly choices out there. List price at
http://www.aage.dk is a humble dkk 995 including local v.a.t. ....

I'm really inclined against active crossovers at the moment e.g. the poor
results the ashly crossover yielded. Something wasn't quite right so a
simple 2 band crossover is going to waste a whole channel of my amp (2x1400W
into 4 ohms) for a midrange that's going to be receiving about 18W of power
before protection kicks in... I'm convinced that the passive crossover I'm
using now sounds a lot better - although it might not be as efficient.
It looks like this at present:
Low pass: 1600Hz -6dB/octave
High pass: 1700Hz -18dB/octave.

After your input, I'm willing to try splitting the low pass into:
900Hz -6dB/octave and 1350Hz or 1600Hz -6dB/octave.



On http://www.ashly.com/powercard they say that:

"The XR-1 Three-Way Crossover features 24dB/octave filters,
"20 Hz Low-cut filter, 360 degree phase control, internally
"adjustable frequency, CD Horn EQ switching, auxiliary outputs,
"and a mode switch for biamped or low only configuration.

An obvious question: just what ashly product is it that you _are_ using?

Ashly BP-41. It's a solid state bass preamp which is considered very
versatile for studio use and behaves similar to a mixing desk. 3 band EQ, 1
band parametric and 12dB/octave active crossover.

Thanks again Peter.
cb

"Peter Larsen" wrote in message
...

Sorry - I meant 18dB. AFAICS the capacitors in the high pass passive
network
should provide the necessary isolation.

What high pass passive network? - we're talking about using an active
network in front of the power amp input and about supplementing it with
a cap in series with the compression driver. If I get you right you have
a third order highpass in the preamp you use, in which case adding a
series cap CAN be done with the aim of increasing the roll-off to 24 dB
pr. octave, it either has to augment the x-over that is used or to be
acting so far below that it does not cause too much effect (phase
change) at the x-over point.

OKOKOKOKOK.....
Here's the confusion: The ashly instrument preamplifier (Model BP-41 has a
built in 12dB/octave active crossover.)
The protection I'm talking about here is an 18dB passive crossover - at
1700Hz (high pass) at the moment (it's being modified all the time) which
I'm using to protect the compression driver for which 12dB 1600Hz is the
recomended min spec.
Here I believe there is no further necessary dc protection or components
(say except an Lpad which is there and a overload protection PTC).


Please understand when such apparent nagging happens that it is about
keeping it relevant also for those that just have similar problems, a
usenet follow up is hardly ever written with just the questionee in
mind.

Sure Peter, I understand very well. It's out of courtesy (something not
always found on usenet) that I respond in this way to what you describe as
nagging. Respect is due and you are helping me a lot already so there's no
reason to start any kind of flame war. I am grateful.


[dimensioning x-over coils]

It is not just about cross-section but also about lenght of copper, i.
e. also about the resistive loss and about how much is acceptable in
the
context of the design.

Very true. Is there any way of calculating the power requirements
though?

Hmmm .... I'll leave this to other people. It is probably somewhat less
simple than looking at its restistance vs. the current through it.

Sorry, I don't want to bother with checking what cap to use in series
with the compression driver for the result of using the ashley to
become
18 dB pr. octave.

/* note to new readers: the ashley instrument preamps internal */
/* x-over is reported as being 18 dB pr. octave */

Actually 12dB/octave.
/* Note to new readers (as this is cross posted) that the 12dB works well on
the compression driver but on the 10" speakers the result was unsatisfactory
with midrange peaks being present.


I don't think it would be useful so no worries. You've been very helpful
and
your advice is very much appreciated. Certainly opened up some avenues
of
thought that are worth experimenting with!

If you want to take the gamble of not using the recommended protection
cap, then it is just that, a gamble and your very own. From your
description of the poweramp the risk is probably not large, just
understand that it is a risk of the order of magnitude of whatever a
repair kit costs. Back in the very old days when I was involved with a
rental company here in Copenhagen the owner of the shop decided against
using any protection caps because they in his opinion were too
detrimental to the sound. He felt the risk was worth it and the
compression drivers that did die had other kinds of overload as cause of
death. It is however the consensus here in aapls that not using
compression driver protection caps constitutes malpractice.

See above - I think we're talking cross purposes here. the 18dB High pass
being used is passive...
I do trust and understand where that experience comes from.


I'm contenplating using another inductor in series with one of the
drivers -
a bit of calculation and I'll test how it sounds in a moment.

I hope you don't see this as a waste of time because I have posted
qhestions
about crossovers elsewhere but this is the only forum that actually has
the
knowledge on the subject in real world applications that I've found.

There is also rec.audio.tech, I have added a crosspost to them in case
the good people there want to supplement.

Thanks.


I realise that you folks deal primarily with bigger issues but it's
really
nice that you can spend the time to help sort out something small.

A cross-over is a cross-over is a cross-over, but concerns may be more
stringent for front of house, and I did read it as being about voice
projection, dual 10" units and a small midrange horn seemed to point in
that general direction.

Sorry about that. the good news is what I've tried already does seem to
confirm your assumptions... It actually has a fairly nice response from
40-17kHz...


The design strategy is however the same and there is still the Behringer
active cross-overs to consider depending on just what functionality your
still only vaguely defined equipment has to offer.

I haven't tried using them, but based on specs something like the

http://www.behringer.com/02_products...X2310&lang=ENG

may or may not do just fine. It is simply meant to constitute an example
of the budget friendly choices out there. List price at
http://www.aage.dk is a humble dkk 995 including local v.a.t. ....

I'm really inclined against active crossovers at the moment e.g. the poor
results the ashly crossover yielded. Something wasn't quite right so a
simple 2 band crossover is going to waste a whole channel of my amp (2x1400W
into 4 ohms) for a midrange that's going to be receiving about 18W of power
before protection kicks in... I'm convinced that the passive crossover I'm
using now sounds a lot better - although it might not be as efficient.
It looks like this at present:
Low pass: 1600Hz -6dB/octave
High pass: 1700Hz -18dB/octave.

After your input, I'm willing to try splitting the low pass into:
900Hz -6dB/octave and 1350Hz or 1600Hz -6dB/octave.



On http://www.ashly.com/powercard they say that:

"The XR-1 Three-Way Crossover features 24dB/octave filters,
"20 Hz Low-cut filter, 360 degree phase control, internally
"adjustable frequency, CD Horn EQ switching, auxiliary outputs,
"and a mode switch for biamped or low only configuration.

An obvious question: just what ashly product is it that you _are_ using?

Ashly BP-41. It's a solid state bass preamp which is considered very
versatile for studio use and behaves similar to a mixing desk. 3 band EQ, 1
band parametric and 12dB/octave active crossover.

Thanks again Peter.
cb

"Peter Larsen" wrote in message
...

Sorry - I meant 18dB. AFAICS the capacitors in the high pass passive
network
should provide the necessary isolation.

What high pass passive network? - we're talking about using an active
network in front of the power amp input and about supplementing it with
a cap in series with the compression driver. If I get you right you have
a third order highpass in the preamp you use, in which case adding a
series cap CAN be done with the aim of increasing the roll-off to 24 dB
pr. octave, it either has to augment the x-over that is used or to be
acting so far below that it does not cause too much effect (phase
change) at the x-over point.

OKOKOKOKOK.....
Here's the confusion: The ashly instrument preamplifier (Model BP-41 has a
built in 12dB/octave active crossover.)
The protection I'm talking about here is an 18dB passive crossover - at
1700Hz (high pass) at the moment (it's being modified all the time) which
I'm using to protect the compression driver for which 12dB 1600Hz is the
recomended min spec.
Here I believe there is no further necessary dc protection or components
(say except an Lpad which is there and a overload protection PTC).


Please understand when such apparent nagging happens that it is about
keeping it relevant also for those that just have similar problems, a
usenet follow up is hardly ever written with just the questionee in
mind.

Sure Peter, I understand very well. It's out of courtesy (something not
always found on usenet) that I respond in this way to what you describe as
nagging. Respect is due and you are helping me a lot already so there's no
reason to start any kind of flame war. I am grateful.


[dimensioning x-over coils]

It is not just about cross-section but also about lenght of copper, i.
e. also about the resistive loss and about how much is acceptable in
the
context of the design.

Very true. Is there any way of calculating the power requirements
though?

Hmmm .... I'll leave this to other people. It is probably somewhat less
simple than looking at its restistance vs. the current through it.

Sorry, I don't want to bother with checking what cap to use in series
with the compression driver for the result of using the ashley to
become
18 dB pr. octave.

/* note to new readers: the ashley instrument preamps internal */
/* x-over is reported as being 18 dB pr. octave */

Actually 12dB/octave.
/* Note to new readers (as this is cross posted) that the 12dB works well on
the compression driver but on the 10" speakers the result was unsatisfactory
with midrange peaks being present.


I don't think it would be useful so no worries. You've been very helpful
and
your advice is very much appreciated. Certainly opened up some avenues
of
thought that are worth experimenting with!

If you want to take the gamble of not using the recommended protection
cap, then it is just that, a gamble and your very own. From your
description of the poweramp the risk is probably not large, just
understand that it is a risk of the order of magnitude of whatever a
repair kit costs. Back in the very old days when I was involved with a
rental company here in Copenhagen the owner of the shop decided against
using any protection caps because they in his opinion were too
detrimental to the sound. He felt the risk was worth it and the
compression drivers that did die had other kinds of overload as cause of
death. It is however the consensus here in aapls that not using
compression driver protection caps constitutes malpractice.

See above - I think we're talking cross purposes here. the 18dB High pass
being used is passive...
I do trust and understand where that experience comes from.


I'm contenplating using another inductor in series with one of the
drivers -
a bit of calculation and I'll test how it sounds in a moment.

I hope you don't see this as a waste of time because I have posted
qhestions
about crossovers elsewhere but this is the only forum that actually has
the
knowledge on the subject in real world applications that I've found.

There is also rec.audio.tech, I have added a crosspost to them in case
the good people there want to supplement.

Thanks.


I realise that you folks deal primarily with bigger issues but it's
really
nice that you can spend the time to help sort out something small.

A cross-over is a cross-over is a cross-over, but concerns may be more
stringent for front of house, and I did read it as being about voice
projection, dual 10" units and a small midrange horn seemed to point in
that general direction.

Sorry about that. the good news is what I've tried already does seem to
confirm your assumptions... It actually has a fairly nice response from
40-17kHz...


The design strategy is however the same and there is still the Behringer
active cross-overs to consider depending on just what functionality your
still only vaguely defined equipment has to offer.

I haven't tried using them, but based on specs something like the

http://www.behringer.com/02_products...X2310&lang=ENG

may or may not do just fine. It is simply meant to constitute an example
of the budget friendly choices out there. List price at
http://www.aage.dk is a humble dkk 995 including local v.a.t. ....

I'm really inclined against active crossovers at the moment e.g. the poor
results the ashly crossover yielded. Something wasn't quite right so a
simple 2 band crossover is going to waste a whole channel of my amp (2x1400W
into 4 ohms) for a midrange that's going to be receiving about 18W of power
before protection kicks in... I'm convinced that the passive crossover I'm
using now sounds a lot better - although it might not be as efficient.
It looks like this at present:
Low pass: 1600Hz -6dB/octave
High pass: 1700Hz -18dB/octave.

After your input, I'm willing to try splitting the low pass into:
900Hz -6dB/octave and 1350Hz or 1600Hz -6dB/octave.



On http://www.ashly.com/powercard they say that:

"The XR-1 Three-Way Crossover features 24dB/octave filters,
"20 Hz Low-cut filter, 360 degree phase control, internally
"adjustable frequency, CD Horn EQ switching, auxiliary outputs,
"and a mode switch for biamped or low only configuration.

An obvious question: just what ashly product is it that you _are_ using?

Ashly BP-41. It's a solid state bass preamp which is considered very
versatile for studio use and behaves similar to a mixing desk. 3 band EQ, 1
band parametric and 12dB/octave active crossover.

Thanks again Peter.
cb

"Peter Larsen" wrote in message
...

Sorry - I meant 18dB. AFAICS the capacitors in the high pass passive
network
should provide the necessary isolation.

What high pass passive network? - we're talking about using an active
network in front of the power amp input and about supplementing it with
a cap in series with the compression driver. If I get you right you have
a third order highpass in the preamp you use, in which case adding a
series cap CAN be done with the aim of increasing the roll-off to 24 dB
pr. octave, it either has to augment the x-over that is used or to be
acting so far below that it does not cause too much effect (phase
change) at the x-over point.

OKOKOKOKOK.....
Here's the confusion: The ashly instrument preamplifier (Model BP-41 has a
built in 12dB/octave active crossover.)
The protection I'm talking about here is an 18dB passive crossover - at
1700Hz (high pass) at the moment (it's being modified all the time) which
I'm using to protect the compression driver for which 12dB 1600Hz is the
recomended min spec.
Here I believe there is no further necessary dc protection or components
(say except an Lpad which is there and a overload protection PTC).


Please understand when such apparent nagging happens that it is about
keeping it relevant also for those that just have similar problems, a
usenet follow up is hardly ever written with just the questionee in
mind.

Sure Peter, I understand very well. It's out of courtesy (something not
always found on usenet) that I respond in this way to what you describe as
nagging. Respect is due and you are helping me a lot already so there's no
reason to start any kind of flame war. I am grateful.


[dimensioning x-over coils]

It is not just about cross-section but also about lenght of copper, i.
e. also about the resistive loss and about how much is acceptable in
the
context of the design.

Very true. Is there any way of calculating the power requirements
though?

Hmmm .... I'll leave this to other people. It is probably somewhat less
simple than looking at its restistance vs. the current through it.

Sorry, I don't want to bother with checking what cap to use in series
with the compression driver for the result of using the ashley to
become
18 dB pr. octave.

/* note to new readers: the ashley instrument preamps internal */
/* x-over is reported as being 18 dB pr. octave */

Actually 12dB/octave.
/* Note to new readers (as this is cross posted) that the 12dB works well on
the compression driver but on the 10" speakers the result was unsatisfactory
with midrange peaks being present.


I don't think it would be useful so no worries. You've been very helpful
and
your advice is very much appreciated. Certainly opened up some avenues
of
thought that are worth experimenting with!

If you want to take the gamble of not using the recommended protection
cap, then it is just that, a gamble and your very own. From your
description of the poweramp the risk is probably not large, just
understand that it is a risk of the order of magnitude of whatever a
repair kit costs. Back in the very old days when I was involved with a
rental company here in Copenhagen the owner of the shop decided against
using any protection caps because they in his opinion were too
detrimental to the sound. He felt the risk was worth it and the
compression drivers that did die had other kinds of overload as cause of
death. It is however the consensus here in aapls that not using
compression driver protection caps constitutes malpractice.

See above - I think we're talking cross purposes here. the 18dB High pass
being used is passive...
I do trust and understand where that experience comes from.


I'm contenplating using another inductor in series with one of the
drivers -
a bit of calculation and I'll test how it sounds in a moment.

I hope you don't see this as a waste of time because I have posted
qhestions
about crossovers elsewhere but this is the only forum that actually has
the
knowledge on the subject in real world applications that I've found.

There is also rec.audio.tech, I have added a crosspost to them in case
the good people there want to supplement.

Thanks.


I realise that you folks deal primarily with bigger issues but it's
really
nice that you can spend the time to help sort out something small.

A cross-over is a cross-over is a cross-over, but concerns may be more
stringent for front of house, and I did read it as being about voice
projection, dual 10" units and a small midrange horn seemed to point in
that general direction.

Sorry about that. the good news is what I've tried already does seem to
confirm your assumptions... It actually has a fairly nice response from
40-17kHz...


The design strategy is however the same and there is still the Behringer
active cross-overs to consider depending on just what functionality your
still only vaguely defined equipment has to offer.

I haven't tried using them, but based on specs something like the

http://www.behringer.com/02_products...X2310&lang=ENG

may or may not do just fine. It is simply meant to constitute an example
of the budget friendly choices out there. List price at
http://www.aage.dk is a humble dkk 995 including local v.a.t. ....

I'm really inclined against active crossovers at the moment e.g. the poor
results the ashly crossover yielded. Something wasn't quite right so a
simple 2 band crossover is going to waste a whole channel of my amp (2x1400W
into 4 ohms) for a midrange that's going to be receiving about 18W of power
before protection kicks in... I'm convinced that the passive crossover I'm
using now sounds a lot better - although it might not be as efficient.
It looks like this at present:
Low pass: 1600Hz -6dB/octave
High pass: 1700Hz -18dB/octave.

After your input, I'm willing to try splitting the low pass into:
900Hz -6dB/octave and 1350Hz or 1600Hz -6dB/octave.



On http://www.ashly.com/powercard they say that:

"The XR-1 Three-Way Crossover features 24dB/octave filters,
"20 Hz Low-cut filter, 360 degree phase control, internally
"adjustable frequency, CD Horn EQ switching, auxiliary outputs,
"and a mode switch for biamped or low only configuration.

An obvious question: just what ashly product is it that you _are_ using?

Ashly BP-41. It's a solid state bass preamp which is considered very
versatile for studio use and behaves similar to a mixing desk. 3 band EQ, 1
band parametric and 12dB/octave active crossover.

Thanks again Peter.
cb