This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah, I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

In the meantime I brought the HF driver home to check it's not voice
coil rub.

Graham

Eeyore wrote:
This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah, I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

In the meantime I brought the HF driver home to check it's not voice
coil rub.

Graham

I imagine that there are variations in lamps, given that they are
designed to provide 'light', not speaker protection. I suspect you'll
find an issue with the driver, though. Swap them around to check and/or
do a sweep test.

I just picked up a set of Bose (I know...they were cheap) 201s at a
thrift store. The only thing wrong with them--besides being Bose--were
the blown out protection lamps in series with the tweeters. Not bad for
$7.99, plus the cost of two lamps...altogether less than $10. They'll
make decent computer speakers for my 12 year old.

jak


jak

jakdedert wrote:

Eeyore wrote:
This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah, I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

In the meantime I brought the HF driver home to check it's not voice
coil rub.

I imagine that there are variations in lamps, given that they are
designed to provide 'light', not speaker protection. I suspect you'll
find an issue with the driver, though. Swap them around to check and/or
do a sweep test.

A 'swap', or rather replacement, was done earlier with no good effect. Hence I
laid the suspicion on the damaged push-ons. I will still test the drivers
though. I have 2 drivers that measure ok plus a third blown one and a
replacement diaphragm.


I just picked up a set of Bose (I know...they were cheap) 201s at a
thrift store. The only thing wrong with them--besides being Bose--were
the blown out protection lamps in series with the tweeters. Not bad for
$7.99, plus the cost of two lamps...altogether less than $10. They'll
make decent computer speakers for my 12 year old.

Nice steal. For undemanding work they aren't *that* bad.

Graham

Eeyore wrote:
This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah, I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

In the meantime I brought the HF driver home to check it's not voice
coil rub.


Some Machs and RCFs use a 24 volt projector lamp. I`ve seen these become
intermittent - they check fine with a meter, but introduce terrible
distortion and crackling under pressure - it sounds just like the driver
diaphragm breaking up. They also easily break if the cabinet is roughly
handled.


Ron

"Ron Johnson" wrote in message
...
Eeyore wrote:
This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

here is a novel thought
DON"T OVERDRIVE THEM
simple and effective

it's what I do
the easiest way to overdrive a speaker is to use a amp larger than the
speakers rateing
George
George

Soundhaspriority wrote:

"Eeyore" wrote in message

This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah, I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

I think it's unlikely, because any fracture causes a local hotspot, which
rapidly leads to failure. I'd look at the socket instead!

I will double check that. Thanks for the tip.


We've probably
all seen strange tin-lead phenomena on lightbulb button contacts. The
constant thermal cycling, the pressure, the dissimilar metals...

Interesting point.

Graham

Ron Johnson wrote:

Eeyore wrote:
This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah, I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

In the meantime I brought the HF driver home to check it's not voice
coil rub.

Some Machs and RCFs use a 24 volt projector lamp.

24V truck lamp here.


I`ve seen these become
intermittent - they check fine with a meter, but introduce terrible
distortion and crackling under pressure - it sounds just like the driver
diaphragm breaking up.

That's EXACTLY what I'm getting. Thanks for the effective conformation.


They also easily break if the cabinet is roughly handled.

Well it has been but the bulb's nicely cushioned.

Graham

George's Pro Sound Company wrote:

"Ron Johnson" wrote
Eeyore wrote:
This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

here is a novel thought
DON"T OVERDRIVE THEM
simple and effective

it's what I do
the easiest way to overdrive a speaker is to use a amp larger than the
speakers rateing

The amps aren't but a blast of HF feedback will do it since it will whistle
through the HF filter. I am as it happens going to fit an 80W P-Audio driver
in the damn second JBL JRX112M that's blown its puny HF driver for the second
time, despite improving JBL's original ineffective bulb protection which was
100% ineffective. Jesus that design is CRAP. 1st order crossover !

Bear in mind these are the 15 year old monitors made of MDF and have been very
little trouble generally over the years.

Graham

"Meat Plow" wrote in message
...
On Fri, 14 Nov 2008 22:44:46 +0000, Eeyore
wrote:

This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah, I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

In the meantime I brought the HF driver home to check it's not voice
coil rub.

Graham

Been using some Wharfedale stage gear for a year or so. The mains are
all protected by lamps. I've replaced two in a year but not
experienced a distorted HF. You'll find problems in the xover or drive
I would assume rather than the lamp.

or maybe it's time to upgrade from that MI grade junk your using
George

Meat Plow wrote:

"George's Pro Sound Company"wrote:
"Meat Plow" wrote in message
Eeyore wrote:

This is a well established technique for preventing voice coils burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah, I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

In the meantime I brought the HF driver home to check it's not voice
coil rub.

Been using some Wharfedale stage gear for a year or so. The mains are
all protected by lamps. I've replaced two in a year but not
experienced a distorted HF. You'll find problems in the xover or drive
I would assume rather than the lamp.

or maybe it's time to upgrade from that MI grade junk your using
George

Who, me?

From what I've heard they're well considered and in the IAG group now.
http://www.internationalaudiogroup.com/

The Chang brothers don't believe in messing about AIUI.
http://www.internationalaudiogroup.c...ve_summary.php

Graham

In article ,
George's Pro Sound Company wrote:

"Ron Johnson" wrote in message
...
Eeyore wrote:
This is a well established technique for preventing voice coils
burning out under conditions of 'overdrive'.

here is a novel thought
DON"T OVERDRIVE THEM
simple and effective

Easily said - but not so easy to do when setting up this sort of
equipment. Let alone when that equipment is being used by all sorts.

it's what I do
the easiest way to overdrive a speaker is to use a amp larger than the
speakers rateing

Strangely that's not always so.

The best solution would be a decent limiter on the amp input - but these
cost if it's not going to sound horrid when it operates. A bulb is a very
cheap solution to help protect the speakers.

--
*If love is blind, why is lingerie so popular? *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
George's Pro Sound Company wrote:

"Ron Johnson" wrote in message
...
Eeyore wrote:
This is a well established technique for preventing voice coils
burning out under conditions of 'overdrive'.

here is a novel thought
DON"T OVERDRIVE THEM
simple and effective

Easily said - but not so easy to do when setting up this sort of
equipment. Let alone when that equipment is being used by all sorts.

it's what I do
the easiest way to overdrive a speaker is to use a amp larger than the
speakers rateing

Strangely that's not always so.

The best solution would be a decent limiter on the amp input - but these
cost if it's not going to sound horrid when it operates. A bulb is a very
cheap solution to help protect the speakers.

No lamps in my meyers.
setting up a system that both sounds good and stays within the limits of the
equipment used is NOT hard, it simply requires one know what they are doing.
a amp equal to the speaker rms rateing will never burn out the speaker
unless the amp is clipped hard and long
it will never exceed the excursion of the speaker unless someone fires a gun
a inch from a mic at foolish gains
set your system up properly and you have no need for these foolish lamps.
create cheap MI gear that is used improperly and you need to limit the abuse
idiots can administer, to save on the warrentte costs
I have never heard a speaker with lamps(I've owned plenty) sound as good as
a speaker with out lamps

again no lamps in my meyers, I do have alimiter but it is set well above
any threshold I pass music at.
why buy a 1000 watt amp then limit it to 300 watts, why not just buy a 300
watt amp?
George

"Meat Plow" wrote in message
...
On Sun, 16 Nov 2008 04:25:13 +0000, Eeyore
wrote:



Meat Plow wrote:

"George's Pro Sound Company"wrote:
"Meat Plow" wrote in message
Eeyore wrote:

This is a well established technique for preventing voice coils
burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this
method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah,
I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would
heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

In the meantime I brought the HF driver home to check it's not voice
coil rub.

Been using some Wharfedale stage gear for a year or so. The mains are
all protected by lamps. I've replaced two in a year but not
experienced a distorted HF. You'll find problems in the xover or
drive
I would assume rather than the lamp.

or maybe it's time to upgrade from that MI grade junk your using
George

Who, me?

From what I've heard they're well considered and in the IAG group now.
http://www.internationalaudiogroup.com/

The Chang brothers don't believe in messing about AIUI.
http://www.internationalaudiogroup.c...ve_summary.php

Graham



We've been using the Warfe pro-audio stuff for a year and have had few
problems. One 2500 watt power amp we used for our 18" subs got sent
back because it was too sensitive and would fault when pushed hard at
4 ohms. The replacement did not exhibit this behavior under the exact
conditions. I've replaced a couple lamp protectors elsewhere.

I wouldn't call Wharfedale junk. It's usable, sounds good and reliable
and a lot less expensive than other name brands.

I consider W home stereo grade gear, not suitable for Pro Live Sound, below
behringer

In article ,
George's Pro Sound Company wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
George's Pro Sound Company wrote:

"Ron Johnson" wrote in message
...
Eeyore wrote:
This is a well established technique for preventing voice coils
burning out under conditions of 'overdrive'.

here is a novel thought
DON"T OVERDRIVE THEM
simple and effective

Easily said - but not so easy to do when setting up this sort of
equipment. Let alone when that equipment is being used by all sorts.

it's what I do
the easiest way to overdrive a speaker is to use a amp larger than the
speakers rateing

Strangely that's not always so.

The best solution would be a decent limiter on the amp input - but
these cost if it's not going to sound horrid when it operates. A bulb
is a very cheap solution to help protect the speakers.

No lamps in my meyers. setting up a system that both sounds good and
stays within the limits of the equipment used is NOT hard, it simply
requires one know what they are doing.

These days always having 'someone who knows what they're doing' is rare.
And even less likely with a small band starting out. So you need to make
equipment as idiot proof as possible.

a amp equal to the speaker rms
rateing will never burn out the speaker unless the amp is clipped hard
and long it will never exceed the excursion of the speaker unless
someone fires a gun a inch from a mic at foolish gains set your system
up properly and you have no need for these foolish lamps.

Either the amp cannot produce enough wally to damage the speakers or it
can - so the gunshot thing is rubbish. But no speaker is designed to
handle DC for long - which is what you can get from a grossly overloaded
amp. To be certain that DC couldn't wreck the speakers would require a
*much* smaller amp than would otherwise make sense. Or, of course, use an
amp which can't pass DC.

create cheap
MI gear that is used improperly and you need to limit the abuse idiots
can administer, to save on the warrentte costs I have never heard a
speaker with lamps(I've owned plenty) sound as good as a speaker with
out lamps

Correctly designed the lamp should have little effect on the sound as its
cold resistance will be very low. Only when it starts to 'protect' will
the resistance increase.

again no lamps in my meyers, I do have alimiter but it is set well
above any threshold I pass music at. why buy a 1000 watt amp then limit
it to 300 watts, why not just buy a 300 watt amp?

Why are you using a limiter at all, then?

--
*Rehab is for quitters.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

George's Pro Sound Company wrote:
"Ron Johnson" wrote in message
Eeyore wrote:

This is a well established technique for preventing voice coils
burning out under conditions of 'overdrive'.

here is a novel thought
DON"T OVERDRIVE THEM
simple and effective

Easily said - but not so easy to do when setting up this sort of
equipment. Let alone when that equipment is being used by all sorts.

And it is. Another new house engineer recently for example.


it's what I do the easiest way to overdrive a speaker is to use a amp
larger than the
speakers rateing

Strangely that's not always so.

Well this is where it gets slightly complicated.


The best solution would be a decent limiter on the amp input - but these
cost if it's not going to sound horrid when it operates. A bulb is a very
cheap solution to help protect the speakers.

But a simple level limiter still won't stop the amp delivering full power say
@ 8kHz. Tweeters aren't meant to see that. It would have to be a frequency
sensitive limiter matched to the crossover. Which has given me a product idea
of course.

Graham

the easiest way to overdrive a speaker is to use a[n] amp
larger than the speaker[']s rateing [sic]

Actually, the easiest way to overdrive a speaker is to play it at a level
where it produces audible distortion. But as most listeners have no idea
what distortion sounds like...

No lamps in my meyers. setting up a system that both sounds good and
stays within the limits of the equipment used is NOT hard, it simply
requires one know what they are doing.

These days always having 'someone who knows what they're doing' is rare.
And even less likely with a small band starting out. So you need to make
equipment as idiot proof as possible.

a amp equal to the speaker rms
rateing will never burn out the speaker unless the amp is clipped hard
and long it will never exceed the excursion of the speaker unless
someone fires a gun a inch from a mic at foolish gains set your system
up properly and you have no need for these foolish lamps.

Either the amp cannot produce enough wally to damage the speakers or it
can - so the gunshot thing is rubbish.

Bull****
excursion aand burning out are completely diffrent
a amp "can" put out several times it's rated power for a instant, enough to
throw a cone. been there already

But no speaker is designed to
handle DC for long - which is what you can get from a grossly overloaded
amp. To be certain that DC couldn't wreck the speakers would require a
*much* smaller amp than would otherwise make sense.

the lamp does nothing twards DC protection. I have caps on my tweeters that
do prevent DC

Or, of course, use an
amp which can't pass DC.

except when they fail.

create cheap
MI gear that is used improperly and you need to limit the abuse idiots
can administer, to save on the warrentte costs I have never heard a
speaker with lamps(I've owned plenty) sound as good as a speaker with
out lamps

Correctly designed the lamp should have little effect on the sound as its
cold resistance will be very low. Only when it starts to 'protect' will
the resistance increase.

the designers activate these lamps at such low power levels they are almost
constantly lit

again no lamps in my meyers, I do have alimiter but it is set well
above any threshold I pass music at. why buy a 1000 watt amp then limit
it to 300 watts, why not just buy a 300 watt amp?

Why are you using a limiter at all, then?

why not properly use a properly sized amp, why would you limit within the
range that your produceing in?
if it ain't loud enough, deploy more gear.
I have limiters for dumb ****s
true story from 1993 at one of my first shows with a guest engineer
like the guy who's talkback mic was draped across my console when he grabbed
it the cable spun the trim pot for the kick drum to max
next hit of the drum I had 7 18 inch speaker cones sitting in the feild
next day I got a limiter
more true lifes adventures

for when the "talent" throws a wireless mic against the wall, but the
limiter didn't stop Marlyn Manson from trashing a Midas console on me with a
cast base mic stand though

george

"William Sommerwerck" wrote in message
...
the easiest way to overdrive a speaker is to use a[n] amp
larger than the speaker[']s rateing [sic]

Actually, the easiest way to overdrive a speaker is to play it at a level
where it produces audible distortion. But as most listeners have no idea
what distortion sounds like...

thats why I don't take direction from the audience
George

"William Sommerwerck" wrote in message
...
the easiest way to overdrive a speaker is to use a[n] amp
larger than the speaker[']s rateing [sic]

Actually, the easiest way to overdrive a speaker is to play it at a level
where it produces audible distortion. But as most listeners have no idea
what distortion sounds like...

OTOH distortion does not destroy speakers, speakers are as happy to play
distortion as clean signal
only when you exceed the heat dissipating ability of the motor do you burn
out a speaker

clipping does not damage speakers and distortion does not damage speakers,
its overheating and over excursion that damages speakers
distortion is one method of achieving overheating, but you can overheat with
a spotlessly clean signal as well

"George's Pro Sound Company" wrote in message
m...

"William Sommerwerck" wrote in message
...


the easiest way to overdrive a speaker is to use a[n] amp
larger than the speaker[']s rateing [sic]

Actually, the easiest way to overdrive a speaker is to play it at a level
where it produces audible distortion. But as most listeners have no idea
what distortion sounds like...

OTOH distortion does not destroy speakers, speakers are as happy to play
distortion as clean signal only when you exceed the heat dissipating
ability
of the motor do you burn out a speaker

Although what you say is true in terms of physics (the speaker's excursion
limits do not have a necessary relationship with its heat-dissipating
capability), in practice, audible distortion is a warning that you should
turn down the volume. William Michael Watson Dayton-Wright told me horror
stories of how he could not design a speaker with sufficient power-handling
capability to keep "deaf" listeners from overdriving and damaging it.


clipping does not damage speakers and distortion does not damage
speakers, it[']s overheating and over excursion that damages speakers
distortion is one method of achieving overheating, but you can overheat
with a spotlessly clean signal as well

The distortion I was talking about was the sort that comes from pushing it
into its excursion limits.

"William Sommerwerck" wrote in message
...
"George's Pro Sound Company" wrote in message
m...

"William Sommerwerck" wrote in message
...


the easiest way to overdrive a speaker is to use a[n] amp
larger than the speaker[']s rateing [sic]

Actually, the easiest way to overdrive a speaker is to play it at a
level
where it produces audible distortion. But as most listeners have no idea
what distortion sounds like...

OTOH distortion does not destroy speakers, speakers are as happy to play
distortion as clean signal only when you exceed the heat dissipating
ability
of the motor do you burn out a speaker

Although what you say is true in terms of physics (the speaker's excursion
limits do not have a necessary relationship with its heat-dissipating
capability), in practice, audible distortion is a warning that you should
turn down the volume. William Michael Watson Dayton-Wright told me horror
stories of how he could not design a speaker with sufficient
power-handling
capability to keep "deaf" listeners from overdriving and damaging it.


clipping does not damage speakers and distortion does not damage
speakers, it[']s overheating and over excursion that damages speakers
distortion is one method of achieving overheating, but you can overheat
with a spotlessly clean signal as well

The distortion I was talking about was the sort that comes from pushing it
into its excursion limits.

I grant you all your points as valid, and bottoming(or farting) a woofer is
truely a horid sound
George

I grant you all your points as valid, and bottoming (or farting)
a woofer is truely a horid sound.

Agreed. I've never heard it called that, but it's an apt description.

What gets you up so early on a Sunday? (I'm on the west coast, and have been
up since 2AM.)

"William Sommerwerck" wrote in message
...
I grant you all your points as valid, and bottoming (or farting)
a woofer is truely a horid sound.

Agreed. I've never heard it called that, but it's an apt description.

What gets you up so early on a Sunday? (I'm on the west coast, and have
been
up since 2AM.)

went out had a couple of dogfish 90 minutes and that set me down early(8pm)
some days your just not tired at 4 am
G

What gets you up so early on a Sunday? (I'm on the west coast,
and have been up since 2AM.)

went out had a couple of dogfish 90 minutes and that set me down
early(8pm) some days your just not tired at 4 am

As in...

http://www.dogfish.com/brewings/Seas...le/3/index.htm

"William Sommerwerck" wrote in message
...
What gets you up so early on a Sunday? (I'm on the west coast,
and have been up since 2AM.)

went out had a couple of dogfish 90 minutes and that set me down
early(8pm) some days your just not tired at 4 am

As in...

http://www.dogfish.com/brewings/Seas...le/3/index.htm

Same brewery but this IPA
http://www.dogfish.com/brewings/Year...A/11/index.htm

I like to protect gear from whatever might come, so I like lamps and polyswiches. I would
be almost as happy with a frequency-selective limiter that could independently account for
the thermal and displacement limits of the tweeter, mid and woofer (with appropriately
different time constants - an even greater challenge), but the reality is that a lamp in
the tweeter circuit handles 80% of abuse, so it's cheap insurance.

But an interesting twist is that with the simple 2nd order HPFs I have been trying (with a
very high Fc, eg 8 kHz, to flatten CD horn response and match sensitivities), a lamp or
polyswitch in the INPUT to the crossover has the nice benefit of also seeing more MF, and
so potentially account for both thermal and displacement limitations. Admittedly the time
constants cannot be independent as would really be required, but it's still better than
having the lamp in the crossover output circuit, and a LOT safer for the amp, which
becomes UNLOADED when the protection operates, instead of shorted.

Tony

"Dave Plowman (News)" wrote in message
...
But no speaker is designed to
handle DC for long - which is what you can get from a grossly overloaded
amp. To be certain that DC couldn't wreck the speakers would require a
*much* smaller amp than would otherwise make sense. Or, of course, use an
amp which can't pass DC.


Jeez...a little knowledge is a dangerous thing.

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

"Eeysore = incorrigible pommy ****wit TROLL "



** QUIT the ****ing CROSS POSTING

ARSEHOLE !!!!

The cross-posting was to relevant groups you clown.

** Those other NGs are NOT compatible with this one.

Yes they are.


** 100% WRONG.

Your autism is showing - big time.

CROSSPOSTING IS AN ABOMINATION !!

Stevenson is the BIGGEST TROLL on Usenet





..... Phil

In article ,
liquidator wrote:

"Dave Plowman (News)" wrote in message
...
But no speaker is designed to handle DC for long - which is what you
can get from a grossly overloaded amp. To be certain that DC couldn't
wreck the speakers would require a *much* smaller amp than would
otherwise make sense. Or, of course, use an amp which can't pass DC.


Jeez...a little knowledge is a dangerous thing.

Suggest you try driving a DC coupled amp into heavy clipping and see the
results to speakers which can nominally handle its output.

--
*A 'jiffy' is an actual unit of time for 1/100th of a second.

Dave Plowman London SW
To e-mail, change noise into sound.