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Jedd Haas
 
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Default Mackie HR824 Woofer Problem

My HR824's have worked well for about 4 years. Recently, both speakers
have had the woofer cut out entirely. I found that cranking the volume for
a moment or two seemed to "unstick" the woofer and get it going again. (As
the volume is cranked, the woofer emits bursts of sound, as if struggling
to come on, hence my description of "unsticking.")

Anyway, I was able to get a spare woofer off ebay for $30, so I replaced
the woofer that had the problem more frequently. As soon as I put the new
woofer in, it started "sticking" but a shot of high volume got it going
right away. (

Because the problem is so intermittent (and the speakers are out of
warranty) I haven't brought them to my local Mackie repair joint. But that
might be the next step, unless anyone has some insight into the problem?
It seems the woofer may not even be the root of the problem.

Incidentally, I noticed some differences between the old woofer and the
replacement. I'll probably check with Mackie, but here are the details in
case anyone knows about this.

Old woofer marked:
490-001-00 2
04 ‡ 811

New woofer marked:
490-001-00
04 ‡ 703

Which suggests the "new" woofer may in fact be older, due to the lower
part numbers? Also, the "old" woofer had an additional magnet
(doughnut-shaped) epoxied to the back of the speaker. The "new" woofer
lacks this magnet. There's a definite difference to the sound; the bass is
not as strong on the "new" speaker. (By changing the bass response setting
on the back, I was able to get the bass closer to the other speaker.)

Perhaps Mackie's parts department will be willing to sell the magnet--but
of course they're not open at the moment. Does anyone know the details on
the speaker differences? Was the additional magnet a "retrofit" or
something like that?

--
Jedd Haas - Artist
http://www.gallerytungsten.com
http://www.epsno.com
  #2   Report Post  
Scott Dorsey
 
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Jedd Haas wrote:
My HR824's have worked well for about 4 years. Recently, both speakers
have had the woofer cut out entirely. I found that cranking the volume for
a moment or two seemed to "unstick" the woofer and get it going again. (As
the volume is cranked, the woofer emits bursts of sound, as if struggling
to come on, hence my description of "unsticking.")


When this happens, does disconnecting the woofer from the amp fix the
problem? If so, it's the amp throwing out major DC offset. If not, the
woofer cone is mechanically sticking.

Anyway, I was able to get a spare woofer off ebay for $30, so I replaced
the woofer that had the problem more frequently. As soon as I put the new
woofer in, it started "sticking" but a shot of high volume got it going
right away. (


This sounds to me like a DC offset problem. Try running it on the bench
with the woofer removed, make it stick, then disconnect it from the amp
and see if you don't have an amp problem.

On the other hand, you might also have got a bad driver off Ebay. It
would not be the first time someone sold pulls from bad equipment on
Ebay.

Perhaps Mackie's parts department will be willing to sell the magnet--but
of course they're not open at the moment. Does anyone know the details on
the speaker differences? Was the additional magnet a "retrofit" or
something like that?


It may well have been a factory change to reduce magnetic leakage or something
like that. But I bet a nickel the problem is the amp.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
  #3   Report Post  
Jedd Haas
 
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In article , (Scott
Dorsey) wrote:

Jedd Haas wrote:
My HR824's have worked well for about 4 years. Recently, both speakers
have had the woofer cut out entirely. I found that cranking the volume for
a moment or two seemed to "unstick" the woofer and get it going again. (As
the volume is cranked, the woofer emits bursts of sound, as if struggling
to come on, hence my description of "unsticking.")


When this happens, does disconnecting the woofer from the amp fix the
problem? If so, it's the amp throwing out major DC offset. If not, the
woofer cone is mechanically sticking.


I'm not following you here; if I disconnect the woofer, how will I know if
the problem is fixed? Are you suggesting putting in another woofer? If
not, won't it be bad for amp to run it with no speaker? Or do you mean to
disconnect the woofer, then reconnect it to see if it works again
immediately?

Anyway, I was able to get a spare woofer off ebay for $30, so I replaced
the woofer that had the problem more frequently. As soon as I put the new
woofer in, it started "sticking" but a shot of high volume got it going
right away. (


This sounds to me like a DC offset problem. Try running it on the bench
with the woofer removed, make it stick, then disconnect it from the amp
and see if you don't have an amp problem.


Again--if the woofer is removed, how do I make it stick or even know it's
sticking? The problem is intermittent woofer cut-out. I'm not sure how to
get it to stick, it does it on its own at random intervals (sometimes days
apart).

Have you seen DC offset problems on the HR824's before? If so, is the fix
(typically) a few parts, or is it major?

--
Jedd Haas - Artist
http://www.gallerytungsten.com
http://www.epsno.com
  #6   Report Post  
Mike Rivers
 
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In article writes:

My HR824's have worked well for about 4 years. Recently, both speakers
have had the woofer cut out entirely. I found that cranking the volume for
a moment or two seemed to "unstick" the woofer and get it going again. (As
the volume is cranked, the woofer emits bursts of sound, as if struggling
to come on, hence my description of "unsticking.")


That sure sounds like an amplifier problem to me. Since you're already
inside the things, try connecting the woofer up to an amplifier that
you know is good to isolate it to either the speaker or the amplifier.
I'd suggest trying a different speaker but if the amplifier is putting
out DC it could ruin another speaker. So you could have an amplifier
problem that caused a speaker problem.

Anyway, I was able to get a spare woofer off ebay for $30


Guaranteed perfect, no doubt. g Why would anyone have the woofer
out of a Mackie HR824 it they didn't replace it with another one?

It seems the woofer may not even be the root of the problem.


Or it may not be the only problem.

Incidentally, I noticed some differences between the old woofer and the
replacement. I'll probably check with Mackie, but here are the details in
case anyone knows about this.


The did go through a couple of different speakers in that cabinet, but
they're all functionally equivalent. But each one is adjusted at the
factory in test chamber (they give you a real frequency response plot
when they're new) so I expect that unless you send them back to the
factory for repair they'll never sound like new with a replacement
speaker. I doubt that a non-factory authorized repair center would
have suitable test facilities, but would just repair the amplifier or
replace the speaker, whatever is required.

Give a call to tech support and see what they say. They'll probably
tell you to send it in for repair.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo
  #7   Report Post  
play-on
 
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Mackie used to be very good about supporting their products, even out
of warranty.

Al

On Sat, 11 Dec 2004 13:04:31 -0600, (Jedd Haas) wrote:

My HR824's have worked well for about 4 years. Recently, both speakers
have had the woofer cut out entirely. I found that cranking the volume for
a moment or two seemed to "unstick" the woofer and get it going again. (As
the volume is cranked, the woofer emits bursts of sound, as if struggling
to come on, hence my description of "unsticking.")

Anyway, I was able to get a spare woofer off ebay for $30, so I replaced
the woofer that had the problem more frequently. As soon as I put the new
woofer in, it started "sticking" but a shot of high volume got it going
right away. (

Because the problem is so intermittent (and the speakers are out of
warranty) I haven't brought them to my local Mackie repair joint. But that
might be the next step, unless anyone has some insight into the problem?
It seems the woofer may not even be the root of the problem.

Incidentally, I noticed some differences between the old woofer and the
replacement. I'll probably check with Mackie, but here are the details in
case anyone knows about this.

Old woofer marked:
490-001-00 2
04 ‡ 811

New woofer marked:
490-001-00
04 ‡ 703

Which suggests the "new" woofer may in fact be older, due to the lower
part numbers? Also, the "old" woofer had an additional magnet
(doughnut-shaped) epoxied to the back of the speaker. The "new" woofer
lacks this magnet. There's a definite difference to the sound; the bass is
not as strong on the "new" speaker. (By changing the bass response setting
on the back, I was able to get the bass closer to the other speaker.)

Perhaps Mackie's parts department will be willing to sell the magnet--but
of course they're not open at the moment. Does anyone know the details on
the speaker differences? Was the additional magnet a "retrofit" or
something like that?


  #8   Report Post  
Bob Cain
 
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Jedd Haas wrote:
My HR824's have worked well for about 4 years. Recently, both speakers
have had the woofer cut out entirely. I found that cranking the volume for
a moment or two seemed to "unstick" the woofer and get it going again. (As
the volume is cranked, the woofer emits bursts of sound, as if struggling
to come on, hence my description of "unsticking.")


Check the bass rolloff switches in back. They can get
intermittant and "microphonic" in a raggedy sort of way.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
  #9   Report Post  
Cyrus
 
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In article ,
Bob Cain wrote:

Jedd Haas wrote:
My HR824's have worked well for about 4 years. Recently, both speakers
have had the woofer cut out entirely. I found that cranking the volume for
a moment or two seemed to "unstick" the woofer and get it going again. (As
the volume is cranked, the woofer emits bursts of sound, as if struggling
to come on, hence my description of "unsticking.")


Check the bass rolloff switches in back. They can get
intermittant and "microphonic" in a raggedy sort of way.


Bob


To the OP: While you're playing with switches, try reseating any
connectors/switch and switch back any switches/hit any buttons and bring
them back to the position they were in.

I'm with the camp that its something in the amp. Usually speakers either
work or don't work.

--
Cyrus

*coughcasaucedoprodigynetcough*


  #15   Report Post  
Roger F
 
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Default

It may be the "Auto Power" circuit is cutting out? Try turning that off
if it is on. (while fiddling with the switches)

Roger Foote



  #16   Report Post  
Mark
 
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Sounds like an oxidized connection someplace in athe amp or in the
speaker.

Mark

  #17   Report Post  
Doug Schultz
 
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Default


"Jedd Haas" wrote in message
...
My HR824's have worked well for about 4 years. Recently, both speakers
have had the woofer cut out entirely. I found that cranking the volume for
a moment or two seemed to "unstick" the woofer and get it going again. (As
the volume is cranked, the woofer emits bursts of sound, as if struggling
to come on, hence my description of "unsticking.")

Anyway, I was able to get a spare woofer off ebay for $30, so I replaced
the woofer that had the problem more frequently. As soon as I put the new
woofer in, it started "sticking" but a shot of high volume got it going
right away. (

Because the problem is so intermittent (and the speakers are out of
warranty) I haven't brought them to my local Mackie repair joint. But that
might be the next step, unless anyone has some insight into the problem?
It seems the woofer may not even be the root of the problem.

Incidentally, I noticed some differences between the old woofer and the
replacement. I'll probably check with Mackie, but here are the details in
case anyone knows about this.

Old woofer marked:
490-001-00 2
04 ‡ 811

New woofer marked:
490-001-00
04 ‡ 703

Which suggests the "new" woofer may in fact be older, due to the lower
part numbers? Also, the "old" woofer had an additional magnet
(doughnut-shaped) epoxied to the back of the speaker. The "new" woofer
lacks this magnet. There's a definite difference to the sound; the bass is
not as strong on the "new" speaker. (By changing the bass response setting
on the back, I was able to get the bass closer to the other speaker.)

Perhaps Mackie's parts department will be willing to sell the magnet--but
of course they're not open at the moment. Does anyone know the details on
the speaker differences? Was the additional magnet a "retrofit" or
something like that?

--
Jedd Haas - Artist
http://www.gallerytungsten.com
http://www.epsno.com


Sounds like there is some cold solder joint on the PCB in the amp
have a look for something heavy in there that has come loose
do the pencil probe to see if wiggling components makes anything happen.

Doug


  #18   Report Post  
Arny Krueger
 
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"Jedd Haas" wrote in message


Also, the "old" woofer had an additional magnet
(doughnut-shaped) epoxied to the back of the speaker. The "new" woofer
lacks this magnet.


Was the additional
magnet a "retrofit" or something like that?


The external magnet is there to reduce the speakers external magnetic field.
It makes the speakers more friendly for CRT monitors.


  #19   Report Post  
Jedd Haas
 
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Thanks for all your replies. I'm leaning toward the flaky connection
theory. (I had a similar problem about six months back that was solved by
switching from the XLR inputs to the TRS inputs.)

So far it hasn't cut out again, so perhaps it was the bass switch or the
wires connecting to the speaker lugs.

--
Jedd Haas - Artist
http://www.gallerytungsten.com
http://www.epsno.com
  #20   Report Post  
 
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Jedd Haas wrote:
Thanks for all your replies. I'm leaning toward the flaky connection
theory. (I had a similar problem about six months back that was

solved by
switching from the XLR inputs to the TRS inputs.)

So far it hasn't cut out again, so perhaps it was the bass switch or

the
wires connecting to the speaker lugs.

--
Jedd Haas - Artist
http://www.gallerytungsten.com
http://www.epsno.com


This exact thing happened to me yesterday.The problem was
a dirty switch on the back.

Scott Alger

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