I've got a lot of big, small and medium speakers that have blown out over
the years. Typically I take them to the attic where they usually make
pretty good bookshelf supports.

In the spirit of domestic harmony, I am cleaning out said attic (anyone
*really* refer to their old college texts or books they have read in the
past anymore?). So with all the books being "de-accessioned"
(librarian-speak for "thrown out") I am left with a lot of bowed knotty pine
planks and burned out speakers.

If they can be salvaged, I can use them, but if they're likely to just blow
out again, I will send them to the curb monster that comes by late at night
before trash day.

So my question is this. Is it worth repairing 10 or 20 year old speakers?
Can replacements be readily had?

Is there a good site for diagnosing speaker problems? I almost always
assume it's a fine wire winding in the voice coil that shorted when a
speaker no longer even responds to a battery "click" test but I that's an
assumption.

Is it possible to match the characteristics of the old speakers closely
enough without manufacturer info like a parts list?

Do crossover networks ever go bad? Can they be tested with a multimeter?

And yes, I googled it,

http://www.google.com/search?q=diagn...ms&btnG=Search

but I didn't like very many of the sites it revealed. I'll keep searching
but Google ain't what she used to be.

Hmm, should have added "blown" to the search term - much better. Still not
great, though.

Thanks in advance for your input.

(Followups to alt.home.repair please!)

--
Bobby G.

anyone *really* refer to their old college texts or books
they have read in the past anymore?

I do, on rare occasion.


You presumably have conventional dynamic speakers. It's unlikely any of them
could stand up to current models in terms of sound quality. (There are
exceptions.)

The fact that these speakers are "blown out" is suspicious. Speakers are
almost always blown out by gross abuse; it doesn't "just happen". As a
"classical snob" listener, I'm tempted to believe you don't deserve to own
good speakers, because you just crank up the volume without regard for whether
you're driving the speakers into distortion, a small step away from damaging
them.

Before repairing or replacing these speakers, you should find out /why/ you're
abusing them.

On 5/21/2014 7:29 PM, William Sommerwerck wrote:
anyone *really* refer to their old college texts or books
they have read in the past anymore?

I do, on rare occasion.


You presumably have conventional dynamic speakers. It's unlikely any of
them could stand up to current models in terms of sound quality. (There
are exceptions.)

The fact that these speakers are "blown out" is suspicious. Speakers are
almost always blown out by gross abuse; it doesn't "just happen". As a
"classical snob" listener, I'm tempted to believe you don't deserve to
own good speakers, because you just crank up the volume without regard
for whether you're driving the speakers into distortion, a small step
away from damaging them.

Before repairing or replacing these speakers, you should find out /why/
you're abusing them.


WHAT!

On 5/21/2014 9:05 PM, amdx wrote:
On 5/21/2014 7:29 PM, William Sommerwerck wrote:
anyone *really* refer to their old college texts or books
they have read in the past anymore?

I do, on rare occasion.


You presumably have conventional dynamic speakers. It's unlikely any of
them could stand up to current models in terms of sound quality. (There
are exceptions.)

The fact that these speakers are "blown out" is suspicious. Speakers are
almost always blown out by gross abuse; it doesn't "just happen". As a
"classical snob" listener, I'm tempted to believe you don't deserve to
own good speakers, because you just crank up the volume without regard
for whether you're driving the speakers into distortion, a small step
away from damaging them.

Before repairing or replacing these speakers, you should find out /why/
you're abusing them.


WHAT!
Bobby,
If your attic is anything like mine with regard to temperature and
humidity control, hitting extremes in both parameters, I would caution
you to look carefully at the outcome of storage. You may find that new
issues now exist which did not arise until heat, cold, dust, etc. have
destroyed other elements of the speaker. The adhesives, rubber,
surrounds, electrolytics, cones, etc. can get irreversibly damaged after
a stay in harsh conditions.

Smarty

"Smarty" wrote in message ...

If your attic is anything like mine with regard to temperature
and humidity control, hitting extremes in both parameters,
I would caution you to look carefully at the outcome of storage.
You may find that new issues now exist which did not arise until
heat, cold, dust, etc. have destroyed other elements of the speaker.
The adhesives, rubber, surrounds, electrolytics, cones, etc. can
get irreversibly damaged after a stay in harsh conditions.

Absolutely valid points. But he said these speakers were blown out before
being put in storage.

On 5/21/2014 11:01 PM, William Sommerwerck wrote:
"Smarty" wrote in message ...

If your attic is anything like mine with regard to temperature
and humidity control, hitting extremes in both parameters,
I would caution you to look carefully at the outcome of storage.
You may find that new issues now exist which did not arise until
heat, cold, dust, etc. have destroyed other elements of the speaker.
The adhesives, rubber, surrounds, electrolytics, cones, etc. can
get irreversibly damaged after a stay in harsh conditions.

Absolutely valid points. But he said these speakers were blown out
before being put in storage.
Yes, and I added that attic storage can further contribute new and
unexpected issues. Expecting a speaker which was 'blown out' with a
fried voice coil on the woofer may surprisingly reveal, after storage,
an inoperative tweeter, damaged by attic heat.

My point in posting this caveat was to caution the original poster that
the condition of the speaker when it was put into attic storage may not
reflect the current status due to the attic environment itself.

"William Sommerwerck" wrote in message
...
"Smarty" wrote in message ...

If your attic is anything like mine with regard to temperature
and humidity control, hitting extremes in both parameters,
I would caution you to look carefully at the outcome of storage.
You may find that new issues now exist which did not arise until
heat, cold, dust, etc. have destroyed other elements of the speaker.
The adhesives, rubber, surrounds, electrolytics, cones, etc. can
get irreversibly damaged after a stay in harsh conditions.

Absolutely valid points. But he said these speakers were blown out before
being put in storage.

I don't know the correct names for speaker bits - but if the cone has been
over extended to the flexible webbing that supports the cone around the
speech coil has torn, there could be all kinds of crap settled in the gap
between the magnet poles.

A tiny minority refurbish their own speakers, a not much bigger minority
take them to specialist rebuilders - either way is unlikely to be cheaper
than buying new ones.

"Smarty" wrote in message
...

stuff snipped

Bobby,
If your attic is anything like mine with regard to temperature and
humidity control, hitting extremes in both parameters, I would caution
you to look carefully at the outcome of storage. You may find that new
issues now exist which did not arise until heat, cold, dust, etc. have
destroyed other elements of the speaker. The adhesives, rubber,
surrounds, electrolytics, cones, etc. can get irreversibly damaged after
a stay in harsh conditions.

Those are good points. It's not too bad up there, but there is a good
possibility that there's heat or aging damage and replacing a bad tweeter or
midrange would just be followed up by the failure of a woofer after the
repaired speaker has been run for a while.

Thanks for your input!

--
Bobby G.

On 5/22/2014 9:05 PM, Robert Green wrote:
"Smarty" wrote in message
...

stuff snipped

Bobby,
If your attic is anything like mine with regard to temperature and
humidity control, hitting extremes in both parameters, I would caution
you to look carefully at the outcome of storage. You may find that new
issues now exist which did not arise until heat, cold, dust, etc. have
destroyed other elements of the speaker. The adhesives, rubber,
surrounds, electrolytics, cones, etc. can get irreversibly damaged after
a stay in harsh conditions.
Those are good points. It's not too bad up there, but there is a good
possibility that there's heat or aging damage and replacing a bad tweeter or
midrange would just be followed up by the failure of a woofer after the
repaired speaker has been run for a while.

Thanks for your input!

--
Bobby G.

Glad to offer an opinion Bobby. My attic can reach well over 100 degrees F in the summer and below 0 in the winter, so the comments I offered were not merely theoretical! I have lost some equipment which was stored in working condition, only to find it inoperative years later. Now I am much more careful about what gets stored up there.

amdx wrote:
On 5/21/2014 7:29 PM, William Sommerwerck wrote:
anyone *really* refer to their old college texts or books
they have read in the past anymore?

I do, on rare occasion.


You presumably have conventional dynamic speakers. It's unlikely any of
them could stand up to current models in terms of sound quality. (There
are exceptions.)

The fact that these speakers are "blown out" is suspicious. Speakers are
almost always blown out by gross abuse; it doesn't "just happen". As a
"classical snob" listener, I'm tempted to believe you don't deserve to
own good speakers, because you just crank up the volume without regard
for whether you're driving the speakers into distortion, a small step
away from damaging them.

Before repairing or replacing these speakers, you should find out /why/
you're abusing them.


WHAT!
Hi,
El Cheapo amps blow speakers more. MY HT is 7.1 all Paradigm speakers
driven by Anthem MRX700.
2 ch. stereo is an old British Quad I mod'd with pair of Mirage M7s.

William Sommerwerck wrote: "You presumably have conventional dynamic speakers. It's unlikely any of them
could stand up to current models in terms of sound quality. (There are exceptions.)"

A disturbing trend(consumer at least) is toward smaller and smaller mains accompanied by or requiring a separate subwoofer. Or taller but narrower floor standing mains. I have a pair of dB Plus with 10" woofers and 1" dome tweeters from 1990 that still sound good - at least to me and most company I invite over - and I don't want to go the separate sub route when replacement time comes. Simple physics tells me that a floor standing model with only 6" woofers isn't going to touch those old Canucks for bottom end!


As for the o.p.: If the only damage is rotted surrounds, there are online resources for modern rubber replacements to recone those attic residents.

wrote in message news:8bb55a7d-bacd-4974-bbad-

As for the o.p.: If the only damage is rotted surrounds, there are online
resources for modern rubber replacements to recone those attic residents.

Haven't even cracked one open yet - just doing my "survey" on my options
before I get to that stage and hopefully will know what to look for. Some
speakers I rescued from friends, some died at the hands of a Sony receiver
that had a motorized volume control that occasionally went crazy and turned
itself to maximum volume, others just sound scratchy, etc.

There's no common cause of death for all of them and most of the attic
denizens are bookshelf speakers, hence their employment as bookshelf
supports. I suspect that once I inspect them, most of them will be fed to
the curbside monster but the larger more expensive ones that weren't stored
in the attic may be worthy of repair.

Thanks for your input!

--
Bobby G.

In sci.electronics.repair Robert Green wrote:
Is it worth repairing 10 or 20 year old speakers?

Depends. Were these $500+/each audiopile speakers when new? If so, it
might be worth it. Did they come as a set with a $150 stereo system?
Maybe not worth it. In between... you have to decide.

Can replacements be readily had?

You can get replacement drivers in various sizes and power handling
levels. You can probably get something "close"; whether that's good
enough for you is up to your ears.

Is there a good site for diagnosing speaker problems?

http://www.repairfaq.org/sam/audiofaq.htm#audloud

I almost always assume it's a fine wire winding in the voice coil that
shorted when a speaker no longer even responds to a battery "click"
test but I that's an assumption.

The voice coil is more likely to be open. Sometimes you get lucky and
it's something easy, like the wire to the connectors/terminals on the
back panel has broken, or a push-on connector has fallen off.

Is it possible to match the characteristics of the old speakers
closely enough without manufacturer info like a parts list?

For higher-end ($$$) speakers, if you can't get exact replacements, you
can probably get parts that have been tested to work well in that
particular model. For cheap speakers, you try it and see.

Do crossover networks ever go bad?

They can.

Can they be tested with a multimeter?

Yes. You can see if the inductors (coils) are open circuit, and you
can check the capacitors for open or short circuits. You most likely
will need to unsolder at least one end of each component to make the
test.

It might be faster to note how the wires go, disconnect the crossovers,
and apply audio to each speaker driver directly. If you get sound, then
put the crossover back in line and run audio through it. If the sound
goes away or becomes hideously bad, then the crossover network is
broken.

(Followups to alt.home.repair please!)

A real newsreader will allow you to set the Followup-To: header as you
desire. (Outhouse Depressed is not a real newsreader.)

Matt Roberds

On 22/05/2014 00:24, Robert Green wrote:
I've got a lot of big, small and medium speakers that have blown out over
the years. Typically I take them to the attic where they usually make
pretty good bookshelf supports.

In the spirit of domestic harmony, I am cleaning out said attic (anyone
*really* refer to their old college texts or books they have read in the
past anymore?). So with all the books being "de-accessioned"
(librarian-speak for "thrown out") I am left with a lot of bowed knotty pine
planks and burned out speakers.

If they can be salvaged, I can use them, but if they're likely to just blow
out again, I will send them to the curb monster that comes by late at night
before trash day.

So my question is this. Is it worth repairing 10 or 20 year old speakers?
Can replacements be readily had?

Is there a good site for diagnosing speaker problems? I almost always
assume it's a fine wire winding in the voice coil that shorted when a
speaker no longer even responds to a battery "click" test but I that's an
assumption.

Is it possible to match the characteristics of the old speakers closely
enough without manufacturer info like a parts list?

Do crossover networks ever go bad? Can they be tested with a multimeter?

And yes, I googled it,

http://www.google.com/search?q=diagn...ms&btnG=Search

but I didn't like very many of the sites it revealed. I'll keep searching
but Google ain't what she used to be.

Hmm, should have added "blown" to the search term - much better. Still not
great, though.

Thanks in advance for your input.

(Followups to alt.home.repair please!)

--
Bobby G.




If this was a UK loft then you've increased the probability of adding
bits of iron-corrossion product , now trapped by the magnet , in the VC
gap , to give that classic scratchy sound, as well as the original failure

"N_Cook" wrote in message
...

stuff snipped

If this was a UK loft then you've increased the probability of adding
bits of iron-corrossion product , now trapped by the magnet , in the VC
gap , to give that classic scratchy sound, as well as the original failure

It's a fairly high humidity Washington DC attic.

I didn't know that ferrous debris in the VC gap was an issue. I thought the
scratchy sound came from the voice coil detaching from the paper/plastic
cone.

Thanks for your input!

--
Bobby G.

On 5/23/14, 4:16 PM, Robert Green wrote:
"N_Cook" wrote in message
...

stuff snipped

If this was a UK loft then you've increased the probability of adding
bits of iron-corrossion product , now trapped by the magnet , in the VC
gap , to give that classic scratchy sound, as well as the original failure

It's a fairly high humidity Washington DC attic.

I didn't know that ferrous debris in the VC gap was an issue. I thought the
scratchy sound came from the voice coil detaching from the paper/plastic
cone.

Thanks for your input!

--
Bobby G.



The surround is supposed to keep the cone (and voice coil) centered. I
think scratching was how I realized something was wrong with my
surrounds. When I glued in a new surround, I'd let the glue set, then
move the cone to be sure it didn't scratch. Of ten speakers, I think I
had to reset one surround. I'm glad I caught it while the glue was soft.

On Mon, 26 May 2014 21:52:39 -0400, J Burns
wrote:

On 5/23/14, 4:16 PM, Robert Green wrote:
"N_Cook" wrote in message
...

stuff snipped

If this was a UK loft then you've increased the probability of adding
bits of iron-corrossion product , now trapped by the magnet , in the VC
gap , to give that classic scratchy sound, as well as the original failure

It's a fairly high humidity Washington DC attic.

I didn't know that ferrous debris in the VC gap was an issue. I thought the
scratchy sound came from the voice coil detaching from the paper/plastic
cone.

Thanks for your input!

--
Bobby G.



The surround is supposed to keep the cone (and voice coil) centered. I
think scratching was how I realized something was wrong with my
surrounds. When I glued in a new surround, I'd let the glue set, then
move the cone to be sure it didn't scratch. Of ten speakers, I think I
had to reset one surround. I'm glad I caught it while the glue was soft.
If the "spider" is good, the surround doesn't do any locating. I
rebuilt 8, 4 of them 12 inchers, With the surrounds totally removed
there was no scratching I didn't need to shim the voice coil, and the
surrounds went on quickly and easily, and the speakers sound
EXCELLENT.They were pretty high end speakers - can't remember the
brand and they are up in the mezzanine so I can't check.

J Burns wrote:
On 5/23/14, 4:16 PM, Robert Green wrote:
"N_Cook" wrote in message
...

stuff snipped

If this was a UK loft then you've increased the probability of adding
bits of iron-corrossion product , now trapped by the magnet , in the VC
gap , to give that classic scratchy sound, as well as the original failure

It's a fairly high humidity Washington DC attic.

I didn't know that ferrous debris in the VC gap was an issue. I thought the
scratchy sound came from the voice coil detaching from the paper/plastic
cone.

Thanks for your input!

--
Bobby G.



The surround is supposed to keep the cone (and voice coil) centered. I
think scratching was how I realized something was wrong with my
surrounds. When I glued in a new surround, I'd let the glue set, then
move the cone to be sure it didn't scratch. Of ten speakers, I think I
had to reset one surround. I'm glad I caught it while the glue was soft.

The surround just keeps shifting. The spider centers the coil. The other
thing, spider can droop in or out. I would make adjustments when doing a
repair. I usually wet it down and holding it in place. Kinda starchy
material.

Greg

On 05/26/2014 06:52 PM, J Burns wrote:
On 5/23/14, 4:16 PM, Robert Green wrote:
"N_Cook" wrote in message
...

stuff snipped

If this was a UK loft then you've increased the probability of adding
bits of iron-corrossion product , now trapped by the magnet , in the VC
gap , to give that classic scratchy sound, as well as the original
failure

It's a fairly high humidity Washington DC attic.

I didn't know that ferrous debris in the VC gap was an issue. I
thought the
scratchy sound came from the voice coil detaching from the paper/plastic
cone.

Thanks for your input!

--
Bobby G.



The surround is supposed to keep the cone (and voice coil) centered. I
think scratching was how I realized something was wrong with my
surrounds. When I glued in a new surround, I'd let the glue set, then
move the cone to be sure it didn't scratch. Of ten speakers, I think I
had to reset one surround. I'm glad I caught it while the glue was soft.

The surround is for acoustic loading. The spider keeps the motor aligned.

On Tue, 27 May 2014 05:33:47 -0700, dave wrote:

On 05/26/2014 06:52 PM, J Burns wrote:
On 5/23/14, 4:16 PM, Robert Green wrote:
"N_Cook" wrote in message
...

stuff snipped

If this was a UK loft then you've increased the probability of adding
bits of iron-corrossion product , now trapped by the magnet , in the VC
gap , to give that classic scratchy sound, as well as the original
failure

It's a fairly high humidity Washington DC attic.

I didn't know that ferrous debris in the VC gap was an issue. I
thought the
scratchy sound came from the voice coil detaching from the paper/plastic
cone.

Thanks for your input!

--
Bobby G.



The surround is supposed to keep the cone (and voice coil) centered. I
think scratching was how I realized something was wrong with my
surrounds. When I glued in a new surround, I'd let the glue set, then
move the cone to be sure it didn't scratch. Of ten speakers, I think I
had to reset one surround. I'm glad I caught it while the glue was soft.

The surround is for acoustic loading. The spider keeps the motor aligned.


Not quite the case. The surround seals the airflow between the cone and
the spider. It also provides axial tilt support for the voice coil. Both
properties are important to overall function.

?-)

"Robert Green" wrote in message
...
I've got a lot of big, small and medium speakers that have blown out over
the years. Typically I take them to the attic where they usually make
pretty good bookshelf supports.

In the spirit of domestic harmony, I am cleaning out said attic (anyone
*really* refer to their old college texts or books they have read in the
past anymore?). So with all the books being "de-accessioned"
(librarian-speak for "thrown out") I am left with a lot of bowed knotty
pine
planks and burned out speakers.

If they can be salvaged, I can use them, but if they're likely to just
blow
out again, I will send them to the curb monster that comes by late at
night
before trash day.

So my question is this. Is it worth repairing 10 or 20 year old speakers?
Can replacements be readily had?

Is there a good site for diagnosing speaker problems? I almost always
assume it's a fine wire winding in the voice coil that shorted when a
speaker no longer even responds to a battery "click" test but I that's an
assumption.

Is it possible to match the characteristics of the old speakers closely
enough without manufacturer info like a parts list?

Do crossover networks ever go bad? Can they be tested with a multimeter?

And yes, I googled it,

http://www.google.com/search?q=diagn...ms&btnG=Search

but I didn't like very many of the sites it revealed. I'll keep searching
but Google ain't what she used to be.

Hmm, should have added "blown" to the search term - much better. Still
not
great, though.

Thanks in advance for your input.

(Followups to alt.home.repair please!)

If you're blowing out speakers with that regularity I expect a sever miss
math in equipment. The second would be a recommendation to have your
hearing check as you may have damaged/serious loss of hearing.

All my kids were big into music. I made sure they wore ear protection at
concerts and especially when they were performing. Unlike me (too many
years near jet engines) they can still hear a pin drop.

"NotMe" wrote in message ...

"Robert Green" wrote in message
...
I've got a lot of big, small and medium speakers that have blown out over
the years. Typically I take them to the attic where they usually make
pretty good bookshelf supports.

In the spirit of domestic harmony, I am cleaning out said attic (anyone
*really* refer to their old college texts or books they have read in the
past anymore?). So with all the books being "de-accessioned"
(librarian-speak for "thrown out") I am left with a lot of bowed knotty
pine
planks and burned out speakers.

If they can be salvaged, I can use them, but if they're likely to just
blow
out again, I will send them to the curb monster that comes by late at
night
before trash day.

So my question is this. Is it worth repairing 10 or 20 year old
speakers?
Can replacements be readily had?

Is there a good site for diagnosing speaker problems? I almost always
assume it's a fine wire winding in the voice coil that shorted when a
speaker no longer even responds to a battery "click" test but I that's an
assumption.

Is it possible to match the characteristics of the old speakers closely
enough without manufacturer info like a parts list?

Do crossover networks ever go bad? Can they be tested with a multimeter?

And yes, I googled it,

http://www.google.com/search?q=diagn...ms&btnG=Search

but I didn't like very many of the sites it revealed. I'll keep
searching
but Google ain't what she used to be.

Hmm, should have added "blown" to the search term - much better. Still
not
great, though.

Thanks in advance for your input.

(Followups to alt.home.repair please!)

If you're blowing out speakers with that regularity I expect a sever miss
math in equipment. The second would be a recommendation to have your
hearing check as you may have damaged/serious loss of hearing.

All my kids were big into music. I made sure they wore ear protection at
concerts and especially when they were performing. Unlike me (too many
years near jet engines) they can still hear a pin drop.

Its when you can't hear a speaker cone hit the opposite wall you need to
worry!

NotMe wrote:
"Robert Green" wrote in message
...
I've got a lot of big, small and medium speakers that have blown out over
the years. Typically I take them to the attic where they usually make
pretty good bookshelf supports.

In the spirit of domestic harmony, I am cleaning out said attic (anyone
*really* refer to their old college texts or books they have read in the
past anymore?). So with all the books being "de-accessioned"
(librarian-speak for "thrown out") I am left with a lot of bowed knotty
pine
planks and burned out speakers.

If they can be salvaged, I can use them, but if they're likely to just
blow
out again, I will send them to the curb monster that comes by late at
night
before trash day.

So my question is this. Is it worth repairing 10 or 20 year old speakers?
Can replacements be readily had?

Is there a good site for diagnosing speaker problems? I almost always
assume it's a fine wire winding in the voice coil that shorted when a
speaker no longer even responds to a battery "click" test but I that's an
assumption.

Is it possible to match the characteristics of the old speakers closely
enough without manufacturer info like a parts list?

Do crossover networks ever go bad? Can they be tested with a multimeter?

And yes, I googled it,

http://www.google.com/search?q=diagn...ms&btnG=Search

but I didn't like very many of the sites it revealed. I'll keep searching
but Google ain't what she used to be.

Hmm, should have added "blown" to the search term - much better. Still
not
great, though.

Thanks in advance for your input.

(Followups to alt.home.repair please!)

If you're blowing out speakers with that regularity I expect a sever miss
math in equipment. The second would be a recommendation to have your
hearing check as you may have damaged/serious loss of hearing.

All my kids were big into music. I made sure they wore ear protection at
concerts and especially when they were performing. Unlike me (too many
years near jet engines) they can still hear a pin drop.


Hmmm,
Not only high power blows speakers. El Cheapo amps can blow speakers
much easier than good amps. Why? Cheap amps have too much garbage in
the output signal. My kids are in music since toddlers. Piano, sax,
flute, drum, guitars. I don't have to tell, they wear ear plugs when
they jam. Me? I am lower brass lifer since high school days. Still
active with local concert band.

On 05/29/2014 08:59 AM, Tony Hwang wrote:
NotMe wrote:



Hmmm,
Not only high power blows speakers. El Cheapo amps can blow speakers
much easier than good amps. Why? Cheap amps have too much garbage in
the output signal. My kids are in music since toddlers. Piano, sax,
flute, drum, guitars. I don't have to tell, they wear ear plugs when
they jam. Me? I am lower brass lifer since high school days. Still
active with local concert band.

It's the clipping in the Power Amp that puts DC pulses of opposite
polarity into the voice coil. Pulses always destroy better than steady
current.

On 05/30/2014 07:16 AM, dave wrote:
On 05/29/2014 08:59 AM, Tony Hwang wrote:
NotMe wrote:



Hmmm,
Not only high power blows speakers. El Cheapo amps can blow speakers
much easier than good amps. Why? Cheap amps have too much garbage in
the output signal. My kids are in music since toddlers. Piano, sax,
flute, drum, guitars. I don't have to tell, they wear ear plugs when
they jam. Me? I am lower brass lifer since high school days. Still
active with local concert band.

It's the clipping in the Power Amp that puts DC pulses of opposite
polarity into the voice coil. Pulses always destroy better than steady
current.


RMS = Peak (in a square wave situation afaik)

On Wed, 21 May 2014 19:24:27 -0400, "Robert Green"
wrote:

I've got a lot of big, small and medium speakers that have blown out over
the years. Typically I take them to the attic where they usually make
pretty good bookshelf supports.

In the spirit of domestic harmony, I am cleaning out said attic (anyone
*really* refer to their old college texts or books they have read in the
past anymore?). So with all the books being "de-accessioned"

I kept all my college texts. I even occasionally lend them out. I keep
much of my pleasure reading as well.

(librarian-speak for "thrown out") I am left with a lot of bowed knotty pine
planks and burned out speakers.

If they can be salvaged, I can use them, but if they're likely to just blow
out again, I will send them to the curb monster that comes by late at night
before trash day.

So my question is this. Is it worth repairing 10 or 20 year old speakers?
Can replacements be readily had?

If you can get or make parts.

Is there a good site for diagnosing speaker problems? I almost always
assume it's a fine wire winding in the voice coil that shorted when a
speaker no longer even responds to a battery "click" test but I that's an
assumption.

Is it possible to match the characteristics of the old speakers closely
enough without manufacturer info like a parts list?

Do crossover networks ever go bad? Can they be tested with a multimeter?

Yes but it is rare.
Yes, they can. They are just capacitors and inductors, separate them and
test the components themselves, capacitors dying is by far the most
frequent failure mode. Replacement parts may be hard to get.

And yes, I googled it,

http://www.google.com/search?q=diagn...ms&btnG=Search

but I didn't like very many of the sites it revealed. I'll keep searching
but Google ain't what she used to be.

Hmm, should have added "blown" to the search term - much better. Still not
great, though.

Thanks in advance for your input.

(Followups to alt.home.repair please!)